Reliability and validity of the brief insomnia questionnaire in the America Insomnia Survey

Article (PDF Available)inSleep 33(11):1539-49 · November 2010with199 Reads
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Abstract
to evaluate the reliability and validity of the Brief Insomnia Questionnaire (BIQ), a fully structured questionnaire developed to diagnose insomnia according to hierarchy-free Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), International Classification of Diseases-10 (ICD-10), and research diagnostic criteria/International Classification of Sleep Disorders-2 (RDC/ICSD-2) general criteria without organic exclusions in the America Insomnia Survey (AIS). probability subsamples of AIS respondents, oversampling BIQ positives, completed short-term test-retest interviews (n = 59) or clinical reappraisal interviews (n = 203) to assess BIQ reliability and validity. the AIS is a large (n = 10,094) epidemiologic survey of the prevalence and correlates of insomnia. adult subscribers to a national managed healthcare plan. None BIQ test-retest correlations were 0.47-0.94 for nature of the sleep problems (initiation, maintenance, nonrestorative sleep [NRS]), 0.72-0.95 for problem frequency, 0.66-0.88 for daytime impairment/distress, and 0.62 for duration of sleep. Good individual-level concordance was found between BIQ diagnoses and diagnoses based on expert interviews for meeting hierarchy-free inclusion criteria for diagnoses in any of the diagnostic systems, with area under the receiver operating characteristic curve (AUC, a measure of classification accuracy insensitive to disorder prevalence) of 0.86 for dichotomous classifications. The AUC increased to 0.94 when symptom-level data were added to generate continuous predicted-probability of diagnosis measures. The AUC was lower for dichotomous classifications based on RDC/ICSD-2 (0.68) and ICD-10 (0.70) than for DSM-IV-TR (0.83) criteria but increased consistently when symptom-level data were added to generate continuous predicted-probability measures of RDC/ICSD-2, ICD-10, and DSM-IV-TR diagnoses (0.92-0.95). these results show that the BIQ generates accurate estimates of the prevalence and correlates of hierarchy-free insomnia in the America Insomnia Survey.

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SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
THIS PAPER PRESENTS DATA ON THE RELIABILITY
AND VALIDITY OF A NEW FULLY STRUCTURED MEA-
SURE OF INSOMNIA THAT WAS DEVELOPED FOR USE
in the America Insomnia Survey (AIS), a large (n = 10,094)
epidemiologic survey of the prevalence and correlates of in-
somnia in a sample of subscribers to a large, national, man-
aged healthcare plan in the United States. This Brief Insomnia
Questionnaire (BIQ) was designed to be administered by an
interviewer. It generates insomnia diagnoses according to the
inclusion criteria of the Diagnostic and Statistical Manual,
Fourth Edition, Text Revision
1
(DSM-IV-TR), International
Classication of Diseases-10
2
(ICD-10), and research diagnos-
tic criteria
3
(RDC), and International Classication of Sleep
Disorders-2
4
(ICSD-2), and systems but without operational-
izing the diagnostic hierarchy rules or organic exclusion rules
in these systems. One important aim of the AIS is to compare
the prevalence and correlates of insomnia across these diagnos-
tic systems to determine the implications of using one system
rather than another. Although a number of self-report scales or
fully structured interviews have shown good concordance with
clinical diagnoses either in patient samples
5-9
or community
samples comparing insomniacs with good sleepers,
10-12
none of
those scales or interviews available generates insomnia diag-
noses according to the denitions and general criteria of all the
systems of interest to the AIS: DSM-IV-TR, ICD-10, and RDC/
ICSD-2. Rather than use multiple existing measures for this
purpose, we developed the BIQ to assess insomnia according
to all of these diagnostic systems. This was done by developing
a set of questions similar to those in other brief screening mea-
sures that were judged by an advisory group of experts in sleep
medicine to have good face validity in operationalizing each of
the relevant criteria in each of the 3 diagnostic systems.
Analysis of the psychometric properties of the BIQ pro-
ceeded in 4 steps. First, we investigated short-term test-retest
reliability of each questionnaire component in a small (n = 59)
probability subsample of AIS respondents, oversampling BIQ
positives who were readministered the BIQ 2 days after the
AIS interview. The retest interval was purposefully kept short
to guarantee that there was very little change in the recall pe-
RELIABILITY AND VALIDITY OF THE BRIEF INSOMNIA QUESTIONNAIRE
Reliability and Validity of the Brief Insomnia Questionnaire in the America
Insomnia Survey
Ronald C. Kessler, PhD
1
; Catherine Coulouvrat, MD
2
; Goeran Hajak, MD
3
; Matthew D. Lakoma, MPH
1
; Thomas Roth, PhD
4
; Nancy Sampson, BA
1
;
Victoria Shahly, PhD
1
; Alicia Shillington, PhD
5
; Judith J. Stephenson, SM
6
; James K. Walsh, PhD
7
; Gary K. Zammit, PhD
8
1
Department of Health Care Policy, Harvard Medical School, Boston, MA;
2
Sano-Aventis, Paris, France;
3
Department of Psychiatry and
Psychotherapy, University of Regensburg, Germany;
4
Sleep Disorders and Research Center, Henry Ford Health System, Detroit, MI;
5
Epi-Q, Inc.,
Oak Brook, IL;
6
HealthCore, Inc., Wilmington, DE;
7
Sleep Medicine and Research Center, St. Luke’s Hospital, St. Louis, MO;
8
Clinilabs, Inc., and
Department of Psychiatry, Columbia University College of Physicians & Surgeons, New York, NY.
Study Objectives: To evaluate the reliability and validity of the Brief Insomnia Questionnaire (BIQ), a fully structured questionnaire developed to
diagnose insomnia according to hierarchy-free Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), International Clas-
sication of Diseases-10 (ICD-10), and research diagnostic criteria/International Classication of Sleep Disorders-2 (RDC/ICSD-2) general criteria
without organic exclusions in the America Insomnia Survey (AIS).
Design: Probability subsamples of AIS respondents, oversampling BIQ positives, completed short-term test-retest interviews (n = 59) or clinical
reappraisal interviews (n = 203) to assess BIQ reliability and validity.
Setting: The AIS is a large (n = 10,094) epidemiologic survey of the prevalence and correlates of insomnia.
Participants: Adult subscribers to a national managed healthcare plan.
Intervention: None
Measurements and Results: BIQ test-retest correlations were 0.47-0.94 for nature of the sleep problems (initiation, maintenance, nonrestorative
sleep [NRS]), 0.72-0.95 for problem frequency, 0.66-0.88 for daytime impairment/distress, and 0.62 for duration of sleep. Good individual-level
concordance was found between BIQ diagnoses and diagnoses based on expert interviews for meeting hierarchy-free inclusion criteria for diag-
noses in any of the diagnostic systems, with area under the receiver operating characteristic curve (AUC, a measure of classication accuracy
insensitive to disorder prevalence) of 0.86 for dichotomous classications. The AUC increased to 0.94 when symptom-level data were added to
generate continuous predicted-probability of diagnosis measures. The AUC was lower for dichotomous classications based on RDC/ICSD-2 (0.68)
and ICD-10 (0.70) than for DSM-IV-TR (0.83) criteria but increased consistently when symptom-level data were added to generate continuous
predicted-probability measures of RDC/ICSD-2, ICD-10, and DSM-IV-TR diagnoses (0.92-0.95).
Conclusions: These results show that the BIQ generates accurate estimates of the prevalence and correlates of hierarchy-free insomnia in the
America Insomnia Survey.
Keywords: Insomnia, reliability, validity, epidemiology, DSM-IV, ICD-10, ICSD-2, RDC
Citation: Kessler RC; Coulouvrat C; Hajak G; Lakoma MD; Roth T; Sampson N; Shahly V; Shillington A; Stephenson JJ; Walsh JK; Zammit GK.
Reliability and validity of the brief insomnia questionnaire in the america insomnia survey. SLEEP 2010;33(11):1539-1549.
Submitted for publication January, 2010
Submitted in nal revised form May, 2010
Accepted for publication July, 2010
Address correspondence to: Ronald C. Kessler, Department of Health
Care Policy, Harvard Medical School 180 Longwood Ave, Boston, MA
02115; Tel: (617) 432-3587; Fax: (617) 432-3588; E-mail: kessler@hcp.
med.harvard.edu
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
riod (the 30 days before interview) and that any lack of concor-
dance in BIQ reports in the test and retest interviews was due
to unreliability rather than to true chance. Second, we exam-
ined the aggregate consistency of prevalence estimates based
on the BIQ with those based on independent, semistructured,
clinical reappraisal interviews in a probability subsample of
AIS respondents (n = 203). As in the test-retest sample, BIQ
positives were oversampled in the clinical reappraisal sample.
Third, we examined individual-level concordance of diagnoses
based on the BIQ and clinical interviews. Fourth, we explored
the possibility of improving concordance by developing pre-
diction equations where BIQ item-level data were added to the
diagnostic classications to predict clinical diagnoses.
METHODS
The Main AIS Sample
The AIS was carried out between October 2008 and July
2009 in a stratied probability sample of 10,094 adult (ages
18 years and older) members of a large (more than 34 million
members) national commercial health plan in the United States.
The sample was restricted to fully insured members enrolled for
at least 12 months to allow medical and pharmacy claims data
to be used in substantive analyses. Sample eligibility was also
limited to members who provided the plan with a telephone
number, could speak English, and had no impairment that lim-
ited their ability to be interviewed over the telephone. The sam-
ple was selected with stratication to match the United States
census population distribution on the cross-classication of age
(18-34, 35-49, 50-64, 65-74 and 75+), sex, urbanicity (Census
Standard Metropolitan Statistical Areas [SMSA], non-SMSA
urbanized areas, and rural areas), and census region (Northeast,
South, Midwest, and West).
The AIS was designed to obtain 10,000 completed inter-
views. Target respondents were sampled in random replicates
of 50, which were constructed to be representative of the popu-
lation on the sociodemographic and geographic selection crite-
ria. Information about previous diagnoses or treatment of sleep
problems was ignored in selecting the sample so as to make
it representative of all plan subscribers. An introductory letter
was sent to target respondents a few days before attempts to
make telephone contact began. The letter explained that the sur-
vey was being carried out “to better understand how health and
health problems affect the daily lives of people,” that respon-
dents were selected randomly, that participation was voluntary,
that responses were completely condential, that participa-
tion would not affect healthcare benets in any way, and that
a $20 incentive was being offered for participation. A toll-free
number was included for respondent questions and opting out.
Once respondents were contacted, verbal informed consent was
obtained before beginning interviews. The Human Subjects
Committee of the New England Institutional Review Board ap-
proved these recruitment, consent, and eld procedures.
Up to 20 call attempts were made to reach each target respon-
dent. Disconnected numbers were traced. Forwarded numbers
were followed. The interview, which used computer-assisted
telephone administration, averaged 39 minutes (with a standard
deviation of 6 minutes). Additional replicates were released as
earlier ones were completed. All cases in all released replicates
were resolved (i.e., an interview, a refusal, or a termination due
to reaching the 20-attempt limit), resulting in a total of 10,094
completed interviews. The cooperation rate (the rate of sur-
vey completion among target respondents with known work-
ing telephone numbers, including respondents who were never
reached) was 65.0%. The 10,094 interviews were weighted for
residual discrepancies between the joint distribution in the sam-
ple and the census population on the cross-classication of the
sociodemographic and geographic selection criteria, although
these variables were only weakly related to the probability of
participation.
The Test-Retest Sample
A probability subsample of 59 AIS respondents was admin-
istered a second brief telephone retest interview 2 days after
their AIS interview to establish the test-retest reliability of the
BIQ symptom questions. This test-retest sample oversampled
BIQ positives. The target-sample size (n = 50), which we some-
what exceeded, was selected to yield 0.90 power to detect a
Pearson correlation of 0.40. The nal retest sample included
23 respondents classied by the initial survey as having in-
somnia, 12 classied as subthreshold cases (i.e., respondents
who reported meeting Criterion A: at least 1 sleep problem, 3
or more days a week 30 minutes a night, 1 month or longer,
but who do not meet full criteria), and 24 randomly selected
respondents representing all others in the AIS sample (i.e.,
those who did not meet Criterion A). Respondents in the third
of these sampling strata are usually referred to as good sleepers.
As noted below, comparisons of respondents screened positive
for insomnia only with good sleepers (i.e., excluding respon-
dents in the rather substantial intermediate group of people who
have at least some symptoms but do not meet full criteria on
the insomnia-screening scale) leads to biased estimated of the
accuracy of insomnia screening scales. It is consequently note-
worthy that our comparison group is not limited to good sleep-
ers but also includes this intermediate stratum of respondents
with some insomnia symptoms. The sample was weighted so
that the weighted proportion of respondents in each of the 3
sampling strata was identical to that in the total weighted AIS
sample and summed to 100%. This weighting took into consid-This weighting took into consid-
eration the poststratication weight used in the main survey so
that signicance tests could be made using appropriate design-
based methods.
Because the recall period for the assessment of insomnia in
both the AIS and the retest survey was the past 30 days, the
retest interviews were carried out 2 days after the main sur-
vey interviews to guarantee that no meaningful true change in
insomnia status occurred in the retest interval, compared with
the recall interval. As is typical in short-term test-retest studies,
retest respondents were informed that we were testing the in-
strument and not testing the accuracy of respondent reports and
were instructed not to try to remember their responses in the
initial interview but, rather, to respond in the way they currently
thought provided the most accurate answers to the questions.
Respondents targeted for retest interviews received verbal no-
tice of selection at the end of their AIS interview. Verbal in-
formed consent was then obtained before scheduling the retest
interview for within the next 2 days. Respondents were paid $20
for participation in the retest interview. The Human Subjects
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
Committee of the New England Institutional Review Board ap-
proved these recruitment, consent, and eld procedures.
The Clinical Reappraisal Sample
A separate (from the test-retest sample) probability sub-
sample of 203 AIS respondents was administered a telephone,
clinical reappraisal interview (described below) within 2 weeks
of their AIS interview to assess the accuracy of the insomnia
diagnoses in the main interview. The target sample size (n =
200) was selected to yield a standard error of 0.10 in estimat-
ing Cohen’s κ,
13
a standard measure of concordance in clinical
reappraisal studies. We slightly exceeded the target sample size.
The clinical reappraisal sample oversampled BIQ positives and
used the same 3-stratum sampling scheme as in the test-retest
sample. The sample included 83 respondents classied in the
main survey as having insomnia, 63 subthreshold cases, and
57 respondents representing all others in the AIS sample (i.e.,
those who did not meet BIQ criteria for either insomnia or sub-
threshold insomnia).
As in the test-retest survey, respondents targeted for the
clinical reappraisal survey received verbal notice of selection
at the end of their AIS interview and provided verbal informed
consent before scheduling their clinical reappraisal interviews.
Each respondent was paid $20 for participation in the clinical
reappraisal survey. The Human Subjects Committee the New
England Institutional Review Board approved these recruit-
ment, consent, and eld procedures. The completed clinical
reappraisal interviews were weighted to adjust for the oversam-
pling of BIQ positives. As in the test-retest sample, this weight-his weight-
ing took into consideration the poststratication weight used in
the main survey so that signicance tests could be made using
appropriate design-based methods.
The Assessment of Insomnia
The BIQ
The BIQ was designed to assess current insomnia by op-
erationalizing DSM-IV-TR inclusion Criteria A (predominant
complaint of difculty initiating or maintaining sleep or NRS
for at least 1 month) and B (the sleep disturbance or associated
daytime fatigue causes clinically signicant distress or impair-
ment ) for a diagnosis of primary insomnia; ICD-10 inclusion
Criteria A (complaint of difculty falling asleep or maintain-
ing sleep or poor quality sleep), B (at least 3 times per week
for at least 1 month), C (preoccupation with sleeplessness and
excessive concern over consequences), and D (marked distress
or interference with activities of daily living) for a diagnosis of
non-organic insomnia; and RDC/ICSD-2 inclusion Criteria A
(difculty initiating or maintaining sleep or waking up too early
or chronically NRS), B (difculty occurs despite adequate op-
portunity and circumstances for sleep), and C (daytime impair-
ment related to the nighttime sleep difculty) for a diagnosis of
insomnia disorder. (The full text of the BIQ and coding rules
for diagnoses are available at www.hcp.med.harvard.edu/wmh/
afliated_studies.php. The instrument is in the public domain
and can be used by other investigators without restriction.) It
should be recalled that RDC and ICSD-2 general criteria for
insomnia were developed to be identical, except that the former
are intended for research applications and the latter for clinical
use.
14
That is why we refer to these as dening RDC/ICSD-2
insomnia.
Due to difculties associated with distinguishing primary in-
somnia from insomnia due to physical, mental, or other sleep
disorders or due to substance or alcohol use,
15
no attempt was
made to operationalize the diagnostic hierarchy rules in DSM-
IV-TR Criteria C and D (the sleep disturbance does not occur
exclusively during the course of narcolepsy, breathing-related
sleep disorder, circadian rhythm sleep disorder, parasomnia,
or another mental disorder) or the organic exclusion rules in
DSM-IV Criterion E (the sleep disturbance is not due to the
direct physiological effects of a substance or general medi-
cal condition) or to specify DSM-IV-TR or RDC/ICSD-2 pri-
mary insomnia or ICD-10 non-organic insomnia in terms of
their respective subtypes. It is noteworthy in this regard that
1 major revision under consideration for DSM-V is to elimi- major revision under consideration for DSM-V is to elimi-
nate the current DSM-IV distinction between primary insomnia
and sleep disorders due to another mental disorder or a general
medical condition in favor of a unitary diagnosis of insomnia
disorder with concurrent specication of clinically comorbid
conditions.
16
This revision would avoid causal attributions for
comorbid conditions, a move consistent with the recommen-
dations of the 2005 National Institutes of Health State of the
Science position on the classication of insomnia disorders.
17
Importantly, the AIS included fully structured assessments of
many of the physical and mental disorders known to be associ-
ated with insomnia so that comorbidity could be studied empiri-
cally. In addition, medical and pharmacy claims data for the 12
months before the interview were obtained from the health plan
for all AIS respondents to allow an investigation of patterns of
comorbidity of insomnia with diagnosed and treated comorbid
conditions.
The BIQ question series began by asking respondents how
many nights out of 7 in a typical week they have problems fall-
ing asleep, how many nights they have problems staying asleep
throughout the night, how many mornings out of 7 they typical-
ly wake up before they want to, and how many mornings they
wake up still feeling tired or unrested. Positive responses were
followed with questions about how long it usually takes to fall
asleep on nights with a problem falling asleep, how much time
they usually spend awake at night on nights they have trouble
sleeping, how many times per night they usually wake up dur-
ing those nights, how long it usually takes them to get back to
sleep once they wake up at night, and how much earlier than
they wished do they awaken in the morning when they awaken
early. Respondents who reported NRS were asked to rate the
severity of their problem waking up feeling tired or unrested
using the response options mild, moderate, severe, and very se-
vere.
Respondents with sleep problems were then asked how
many weeks, months or years these problems had been going
on in order to operationalize the 1-month duration requirement
in DSM-IV-TR and ICD-10. They were also asked 2 questions
about adequate opportunity to sleep prefaced with the preamble
“(t)he next questions are about how much your sleep problems
are caused by the place you sleep being too light, too noisy, too
hot or cold, or uncomfortable.” The rst question was: “How
much do you think your sleep problems are caused by prob-
lems with the place you sleep—would you say not at all, a little,
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
severity to the rst 8 questions, 7 to 10 on items of the Sheehan
Disability Scales, and either at least moderate concern or worry
about sleep or much or very much worry or distress about sleep.
The latter 2 items were also used to dene ICD-10 Criterion C.
The semistructured assessment in the clinical reappraisal survey
As noted above, the clinical reappraisal interviews were ad-
ministered over the telephone. Telephone administration is now
widely accepted in clinical reappraisal studies of psychiatric
disorders based on evidence of validity comparable with in-per-with in-per- in-per-
son administration.
19-21
The semistructured research diagnostic
interview schedule was developed specically for this project.
It included DSM, ICD, and RDC/ICSD-2 symptom checklists,
scripted initial questions, suggested probes, spaces to record
notes, and interviewer-based rating categories of denite, prob-
able, possible, and no for each rated symptom. Clinical inter-
viewers were blinded to respondents’ reports on the AIS when
conducting clinical reappraisal interviews.
The seven 7 clinical interviewers were all PhD-level licensed
psychologists with a specialization in the diagnosis and treat-
ment of insomnia and between 6 and 20+ years of clinical ex-
perience diagnosing and treating sleep disorders. Five of the
seven 7 had a Certicate in Behavioral Sleep Medicine from the
American Academy of Sleep Medicine. One of the remaining
2 was both a PhD-level clinical psychologist and a registered
polysomnographic technologist. The nal interviewer was a
PhD-level clinical psychologist who specialized in cognitive
behavioral therapy for sleep disorders.
Interviewer training took place over 2 sessions that focused
on review of the data-collection protocol, discussion of diag-
nostic criteria, and practice in administration and scoring of
the semistructured clinical interview. The supervisor was a
PhD-level clinical psychologist with extensive experience ad-
ministering and supervising research diagnostic interviews of
sleep disorders. The supervisor also provided 1-on-1feedback
to interviewers in practice and production interviews based on
review of digitally recorded clinical interviews and hard-copy
interviews. The supervisor independently scored 15% of these
interviews. Symptom-level supervisor-interviewer interrater
agreement less than κ = 0.85 prompted immediate contact of the
interviewer to resolve ratings differences. Aggregate diagnosis-
level supervisor-interviewer interrater agreement (κ) before
reconciliation across all the dually rated interviews in this ran-
dom 15% sample of clinical interviews was 0.95 for diagnoses
based on DSM, 1.0 for ICD, 0.86 for RDC/ISCD-2, and 0.95
for any criteria.
Initial inspection of associations between AIS and clinical
interview reports found that a number of respondents denied
having any sleep problems in the clinical reappraisal interviews
despite reporting sleep problems in the AIS. To address this is-
sue of respondent-reporting inconsistency, reconciliation inter-
views were carried out by the clinical interviewer supervisor
with 16 respondents classied as meeting criteria for insomnia
according to at least 1 of the diagnostic systems in the AIS and
either not meeting criteria (n = 9) or continuing to meet criteria
(n = 7) in the clinical reappraisal survey. Respondents were re-
minded of their main survey responses at the beginning of these
reconciliation interviews. Clinical probes were then used to
judge whether or not these symptoms met criteria for insomnia
some, a lot, or totally?” The second question was: “Some peo-
ple have sleep problems because they either have to get up very
early, stay up late, or get up in the night because of their job or
because of having a baby or a sick person who needs their help.
How much do you think your sleep problems are caused by
these kinds of demands on your time—would you say not at all,
a little, some, a lot, or totally?”
Respondents with sleep problems were then asked 16 ques-
tions about daytime distress and impairment. The rst 8 of these
questions asked how much difculty respondents had because
of their sleep problems over the past 30 days in each of the fol-
lowing areas: reduced motivation; performance at work, school,
or social activities; making errors or having accidents; irritabil-
ity, nerves, or mood disturbance; daytime attention, concentra-
tion, or memory problems; daytime fatigue; daytime sleepiness;
tension headaches; or digestive problems. The response options
were none, mild, moderate, or severe difculty. The next 4
distress-impairment questions were a modied version of the
Sheehan Disability Scales
18
that asked respondents to rate the
extent to which their sleep problems interfered with their daily
activities during the past 4 weeks using a 0-to-10scale, where 0
means no interference and 10 means very severe interference.
The 4 areas of role functioning were: “your home management,
like cleaning, shopping, and taking care of your home; your
ability to work; your social life; and your close personal rela-
tionships.” Respondents were reminded of the anchors before
answering each question and were also instructed that they
could use any number between 0 and 10 to answer.
The next 2 distress-impairment questions asked about days
out of role due to sleep problems: “About how many days out
of 30 in the past month were you totally unable to work or carry
out your other usual daily activities because of problems with
your sleep? About how many days out of 365 in the past year
were you totally unable to work or carry out your other usual
daily activities because of problems with your sleep?” The nal
2 distress-impairment questions asked respondents how much
concern or worry they had about their sleep (response options:
none, mild, moderate, and severe) and how worried or dis-
tressed they were about their sleep problems (response options:
not at all, a little, some, much, and very much).
A variety of coding schemes were used to combine BIQ ques-
tion responses to generate diagnoses. The nal scheme dened
DSM-IV-TR Criterion A, ICD-10 Criteria A and B, and RDC/
ICSD-2 Criterion A as requiring at least 30 days of problems
initiating sleep 3 or more nights a week, with an average of 30
or more minutes to fall asleep at night; problems staying asleep
3 or more nights a week, with an average of 30 minutes of being
awake; waking 3 or more times a night 3 or more nights a week;
waking too early 3 or more nights a week, with an average of
30 or more minutes too early; or NRS with at least moderate
severity 3 or more nights a week. RDC/ICSD-2 Criterion B
was dened as requiring the respondent to not report that their
sleep problems were caused a lot or totally by problems with
the place they sleep and that the problems were not caused a lot
or totally by demands on their time that required them to sleep
irregularly. DSM-IV-TR Criterion B, ICD-10 Criterion D, and
RDC/ICSD-2 Criterion B were dened as requiring endorse-
ment of at least 2 (1 in the case of RDC/ICSD-2) of the dis-1 in the case of RDC/ICSD-2) of the dis- in the case of RDC/ICSD-2) of the dis-
tress-impairment questions with responses of at least moderate
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
noncase. Although originally developed to study the association
between a continuous predictor and a dichotomous outcome,
AUC can be used in the special case in which the predictor is a
dichotomy, in which case AUC equals (SN + SP)/2. As a result
of this useful interpretation, we focus on AUC in our evaluation
of concordance between diagnoses based on the AIS and the
clinical interviews. We also report SN and SP, the key com-
ponents of AUC in the dichotomous case, as well as positive
predictive value (PPV; the proportion of BIQ cases conrmed
by the clinical interviews), negative predictive value (NPV; the
proportion of BIQ noncases conrmed as noncases by the clini-
cal interviews), and κ.
We next estimated a series of stepwise logistic-regression
equations, in which clinical diagnoses were treated as dichot-
omous outcomes and BIQ symptom variables were included
along with BIQ diagnoses as predictors, to determine whether
BIQ symptom-level data improve the prediction of clinical di-
agnoses, compared with prediction based on BIQ diagnoses.
Signicant improvement of this sort can be used to generate
predicted probabilities of clinical diagnoses for each survey re-
spondent not in the clinical reappraisal sample. As discussed in
more detail elsewhere,
28
diagnostic imputations based on these
predicted probabilities can then be used to make estimates of
the prevalence and correlates of clinical diagnoses in the full
sample so as to incorporate the analysis of validity into substan-
tive investigations. For example, it is possible in this way to
carry out parallel analyses of the extent to which the correlates
of predicted clinical diagnoses differ from the correlates of BIQ
diagnoses.
The AUC was the statistic used to describe these improve-
ments. As noted above, the AUC is typically used with a dimen-
sional predictor and a dichotomous outcome. As a result, it is a
simple matter to think of the AUC as the association between
a predicted probability of a dichotomous outcome, in our case
based on a prediction either from the dichotomous BIQ case
classication or from a logistic-regression equation containing
both BIQ diagnoses and symptom measures as predictors, and
the observed classication on the outcome. This makes it pos-
sible to evaluate the extent to which AUC increases as more
complex predictors are added to an equation over and above the
initial BIQ dichotomous diagnostic classication.
Statistical signicance was consistently evaluated in all of
the above analyses using 0.05-level 2-sided tests. The Taylor
series linearization method
29
was used to adjust estimates of
statistical signicance for the effects of weighting. All the stan-
dard errors reported here are design-based estimates that were
obtained using the Taylor series method.
RESULTS
Test-Retest Reliability
Good short-term (2 days) test-retest reliability was found
for most core BIQ items. Test-retest Pearson correlations are in
the range 0.72 to 0.95 for reports about numbers of nights in a
typical week respondents have problems falling asleep, staying
asleep, waking too early, and feeling unrested after a full night’s
sleep (Table 1). Correlations are also quite high for reports of
how long it takes to fall asleep (0.75), amount of time awake
at night (0.80), and average number of nighttime awakenings
in each of the diagnostic systems, with the supervisor blinded
as to the results of the rst clinical reappraisal interview. Fi-
nal diagnoses of these discrepant cases were based on LEAD
standard procedures
22
that used the information in both of the
2 clinical interviews. The method of multiple imputation
23
was
used to impute nal clinical diagnoses based on the results of
the reconciliation interviews to discrepant cases when recon-
ciliation interviews could not be carried out. Multiple imputa-
tion adjusts standard errors of descriptive statistics to account
for the increases in measurement error introduced by imputed
missing values.
Analysis Methods
After weighting the test-retest sample data to adjust for the
oversampling of BIQ positives, we investigated the stability of
the responses at both the aggregate and individual levels. At the
aggregate level, we compared test and retest interview means.
At the individual level, we calculated Pearson correlations be-
tween reports made in the 2 interviews.
After weighting the clinical reappraisal sample data to ad-
just for the oversampling of BIQ positives, we investigated
concordance between diagnoses based on the BIQ and the
clinical interviews at both the aggregate and individual lev-
els. At the aggregate level, we compared prevalence estimates
based on the 2 methods using McNemar χ
2
tests. Individual-
level diagnostic concordance was then evaluated using 2
different descriptive measures, the area under the receiver op-the area under the receiver op-
erating characteristic curve (AUC)
24
and κ. Although κ is the
most widely used measure of concordance in validity studies
of psychiatric disorders, it has been criticized because it is de-
pendent on prevalence and, consequently, is often low in situ-
ations in which there appears to be high agreement between
low-prevalence measures.
25
An important implication is that κ
varies across populations that differ in prevalence even when
the populations do not differ in sensitivity (SN; the percentage
of true cases correctly classied by the AIS) or specicity (SP;
the percentage of true noncases correctly classied). Because
SN and SP are considered to be fundamental parameters, this
means that the comparison of κ across different populations
cannot be used to evaluate the cross-population performance
of a test.
Critics of κ prefer to assess concordance with measures that
are a function of SN and SP. The odds ratio (OR) meets this
requirement, as OR is equal to [SN × SP]/[(1-SN) × (1 - SP)].
26
However, the upper end of the OR is unbounded, making it dif-
cult to interpret the OR as a measure of concordance. Yule’s
Q has been proposed as an alternative measure to resolve this
problem,
27
as Q is a bounded transformation of OR [Q = (OR
- 1)/(OR + 1)] that ranges between -1 and +1. Q can be in-
terpreted as the difference in the probabilities of a randomly
selected clinical case and a randomly selected clinical noncase
that differ in their classication in the clinical interview being
correctly versus incorrectly classied by the BIQ. The difculty
with Q is that “tied pairs” (i.e., clinical cases and noncases that
have the same BIQ classication) are excluded, which means
that Q does not tell us about actual prediction accuracy.
AUC is a measure that resolves this problem, as AUC can be
interpreted as the probability that a randomly selected clinical
case will score higher on the AIS than will a randomly selected
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
acceptably low test-retest correlation, number of months
with sleep problems (0.62), is due to instability in the
reports of respondents with subthreshold sleep problems.
The correlation is much higher (0.81) among respondents
who reported in the AIS that their sleep problems occur
at least 3 nights a week.
Mean values of BIQ symptom reports are generally
similar for the test and retest interviews, although the
within-person change scores are statistically signicant
for 4 items (number of nights of NRS, number of awak-4 items (number of nights of NRS, number of awak- items (number of nights of NRS, number of awak-
enings per night, difculties caused by sleep problems,
and the Sheehan Disability Scales), all with higher means
in the test than in the retest. This indicates that the test-
retest correlations are likely to be downwardly biased by
effects of repeat administration on reduced reports.
Concordance of Diagnoses Based on the BIQ and Clinical
Interviews
Prevalence estimates based on the BIQ were com-
pared with those based on clinical interviews in the clini-
cal reappraisal sample for each of the diagnostic systems.
McNemar tests show that the prevalence estimates differ
signicantly for DSM-IV-TR, RDC/ICSD-2, and any di-
agnosis but not for ICD-10 diagnoses (Table 2). Preva-
lence estimates based on the BIQ were lower than those
based on the clinical interviews, resulting in PPV consis-
tently being higher than SN.
Using established descriptors for the values of κ,
31
individual-level concordance between diagnoses based
on the BIQ and the clinical interviews is substantial
in the range 0.61-0.80; AUC in the range 0.81-0.90) for
diagnoses based on DSM-IV-TR and any criteria, fair to
moderate in the range 0.41-0.60; AUC in the range
0.61-0.70) for diagnoses based on RDC/ICSD-2 crite-
ria, and fair (κ in the range 0.20-0.40; AUC in the range
0.61-0.70) for diagnoses based on ICD-10 criteria. The
majority of clinical cases are detected by the BIQ (SN)
for DSM-IV-TR and any criteria (67.6%-72.6%) but not
by RDC/ICSD-2 or ICD-10 criteria (41.7%-42.5%). The
vast majority of BIQ cases are conrmed by the clini-
cal interviews (PPV) using DSM-IV-TR and any criteria
(95.5%-96.7%), compared with smaller proportions us-with smaller proportions us- smaller proportions us-
ing RDC/ICSD-2 (70.9%) and ICD-10 (42.7%) criteria.
As might be expected given the BIQ underestimation
of prevalence, the vast majority of clinical noncases are
classied accurately by the BIQ (SP) for all diagnostic
systems (94.4%-98.9%). In a similar way, the proportions of
BIQ noncases conrmed by the clinical interviews (NPV) are
consistently high (83.1%-97.7%).
Bias Introduced by Using Super-Normal Controls
As noted in the introduction, a number of previously devel-
oped self-report insomnia scales were validated in community
samples by comparing the scale scores of conrmed insom-
niacs with those of good sleepers.
10-12
This approach excludes
people who have some evidence of sleep problems but do not
meet full criteria for insomnia in a clinical interview. For ex-
ample, the validity of a short insomnia questionnaire known
as the Sleep Disorders Questionnaire (SDQ)
32
was evaluated
(0.94). Correlations for assessments of daytime impairment and
distress due to sleep problems are in the range 0.71 to 0.88.
Four of the BIQ symptom reports have test-retest correlates
lower than the 0.70, which is generally considered the mini-
mum acceptable level.
30
One of these 4, NRS (0.47), is unstable
due to only 7 retest respondents reporting NRS. Two others,
amount of time waking too early in the morning (0.51) and
number of days out of role due to sleep problems in the past
month (0.66), are inuenced by wide observed response ranges.
When responses are dichotomized (0-29 vs 30+ minutes waking
too early and 0 vs 1+ days out of role), the test-retest tetrachoric
correlations become much higher (0.86 for waking too early;
0.84 for days out of role). The nal symptom report with an un-
Table 1—Short-term (2 days) test-retest reliability of continuous Brief Insomnia
Questionnaire component measures of sleep problems in the weighted America
Insomnia Survey test-retest sample of 59 adults
a
I. Number of nights per week
Time 1 Time 2
Pearson
r
Mean SD Mean SD
Problems falling asleep 0.9 (1.6) 1.0 (1.8) 0.87
c
Waking in the night 1.3 (2.3) 1.2 (2.2) 0.95
c
Waking too early in the morning 2.4 (2.5) 2.2 (2.3) 0.72
c
Nonrestorative sleep 3.3
b
(2.2) 2.8 (2.4) 0.80
c
II. Severity on nights of occurrence
Sleep latency, min 26.0 (43.6) 27.1 (43.7) 0.75
c
Amount of time awake at night, min 29.0 (63.2) 19.1 (41.5) 0.80
b
Number of awakenings per night 0.8
b
(1.6) 0.7 (1.3) 0.94
c
Earliness of waking in morning, min 26.9 (46.2) 18.8 (26.6) 0.51
b
Severity of nonrestorative sleep 1.1 (0.6) 1.0 (0.6) 0.47
c
III. Daytime impairment/distress
Difculties caused by sleep problems
d
1.5
b
(0.5) 1.4 (0.4) 0.87
c
Sheehan Disabilities Scales
e
0.9
b
(1.3) 0.6 (1.0) 0.88
c
Days out of role
f
0.2 (1.0) 0.1 (0.6) 0.66
c
Concern/worry/distress about sleep
g
-0.1 (0.8) -0.2 (0.9) 0.71
c
IV. Duration of sleep problems
Number of months 53.8 (89.6) 42.5 (57.8) 0.62
c
a
Signicant within-individual difference in scores in the test and retest interviews
based on a 0.05-level 2-sided test.
b
Signicant correlations between test and retest scores based on a 0.05-level,
2-sided test.
c
The data were weighted to adjust for the oversampling of respondents classied in
the Brief Insomnia Questionnaire as meeting criteria for insomnia or subthreshold
insomnia.
d
Mean responses to 8 questions about how much difculty respondents had
because of their sleep problems over the past 30 days in reduced motivation;
performance at work, school, or social activities; making errors or having accidents;
irritability, nerves, or mood disturbance; daytime attention, concentration, or
memory problems; daytime fatigue; daytime sleepiness; tension headaches; or
digestive problems. Response options were 1-4 (none, mild, moderate, severe).
e
Mean responses to 4 questions about how much sleep problems interfered with
daily activities during the past 4 weeks in home management, ability to work, social
life, and close personal relationships. Response options were 0-10 (none to very
severe interference).
f
Days out of role (0-30) due to sleep problems in the past month.
g
Standardized (to mean 0 and standard deviation 1.0) responses to 2 questions
about concern/worry (none, mild, moderate, and severe) and worry/distress (not at
all, a little, some, much, and very much) about sleep problems.
SLEEP, Vol. 33, No. 11, 2010
1545
Reliability & Validity of the BIQ in the AIS—Kessler et al
a week for 1 month or longer) but failed to meet full criteria
for insomnia in the BIQ. Results show clearly that concordance
estimates are substantially inated in this way. (Table 3); κ in-
creases from 0.40 to 0.77 in the full sample to 0.53 to 0.91.
AUC increases from 0.68 to 0.86 in the full sample to 0.84 to
0.95. These increases are due to consistently larger increases in
SN (from 41.7-72.6 to 93.7-100.0) than decreases in SP (from
94.4-98.9 to 73.6-93.8) when noncases with sleep problems are
excluded from consideration.
Concordance Based on Continuous Classifications Using BIQ
Symptom Data
Stepwise logistic-regression analysis was used to select BIQ
symptom questions that signicantly predict clinical diagno-
ses after controlling for dichotomous BIQ diagnoses. Each re-
spondent in the clinical reappraisal sample was then assigned
a predicted probability of each clinical diagnosis based on the
resulting logistic-regression equations (Table 4). The AUC for
these predicted probability measures predicting clinical diagno-
ses were substantially higher than the AUC for the dichotomous
BIQ diagnostic classications in predicting clinical diagnoses
based on RDC/ICSD-2 (0.92 vs 0.68) and ICD-10 (0.95 vs 0.70)
criteria and somewhat higher in predicting diagnoses based on
DSM-IV-TR (0.92 vs 0.83) and any (0.94 vs 0.86) criteria.
The improved predictions of diagnoses using the continuous
rather than dichotomous classications is due to the fact that
dichotomous classications do not take into consideration the
fact that some respondents are closer to the diagnostic threshold
than are other respondents. This information is taken into ac-
count in calculating predicted probabilities of diagnoses, result-
ing in ROC curves with good discrimination between cases and
controls throughout the range of the distributions (Figure 1). In
addition to the values of AUC being higher, bias in prevalence
estimates is removed when predicted probabilities of clinical
diagnoses are used instead of diagnoses based on dichotomous
BIQ disorder classications.
in a sample of college students who
were recruited based on SDQ scores
obtained in a classroom screening
exercise.
12
Respondents were divided
into 3 mutually exclusive and collec-3 mutually exclusive and collec- mutually exclusive and collec-
tively exhaustive subgroups based
on these screening scores: those who
did not complain of any sleep prob-
lems (A), those who reported sleep
problems but did not meet diagnostic
criteria of the SDQ for insomnia (B),
and those who met diagnostic crite-
ria for insomnia in the SDQ (C). An
accredited expert in sleep medicine
then carried out clinical interviews
to evaluate the accuracy of diagnoses
based on the SDQ among respon-
dents in subgroups A and C. Impor-
tantly, respondents in subgroup B
were excluded. Control groups of
this sort, which exclude people with
subthreshold evidence of the syn-
drome under study, are referred to in
the methodologic literature as super-normal controls.
33
Super-normal control groups are often favored in studies
designed to detect risk factors that have subtle effects specic
to particular disorders.
34,35
However, this usually introduces up-
ward bias in the estimate of AUC in validity studies because
the increase in SN (due to the omitted true positives all being
screened negatives) is typically greater than the decrease in SP
(due to the omitted true negatives all being screened negatives)
because the proportion of all true positives who are in subgroup
B is usually greater than the proportion of all true negatives
who are in subgroup B, and AUC is the average of SN and SP.
36
It is important to note that the sampling strategy used in
the AIS clinical reappraisal study is different in an important
way from the super-normal control approach in that all AIS
respondents had a non-0 probability of selection into the clini-
cal reappraisal sample. As in the super-normal control design,
we began with 3 sampling strata: respondents who reported
no sleep problems (A), respondents who reported some sleep
problems who did not meet the caseness criteria (B), and BIQ
cases (C). Unlike the situation with super-normal sampling,
in which only respondents in strata A and C are sampled, we
included respondents in all 3 strata in the clinical reapprais-3 strata in the clinical reapprais- strata in the clinical reapprais-
al sample. Even though respondents in strata B and C were
oversampled, the data were weighted to adjust for this overs-
ampling prior to carrying out analysis. The weighted data had
the same sample proportions in the 3 strata as in the full AIS
sample.
The results reported here for concordance of BIQ diagnoses
with clinical diagnoses will inevitably be compared with the
results of published validations of other insomnia measures in
community samples even though the latter studies usually used
super-normal controls. Based on this realization, we examined
the effect of using super-normal controls on estimates of BIQ
validity by replicating the validity analyses reported in the last
section after excluding from the clinical reappraisal sample re-
spondents who reported some sleep problems (2 or more days
Table 2—Consistency of diagnoses based on the Brief Insomnia Questionnaire with diagnoses based on
clinical interviews in the weighted America Insomnia Scale clinical reappraisal sample of 203 adults
a
Criteria
DSM-IV-TR ICD-10 RDC/ICSD-2 Any
McNemar χ
2
test
a
760.2
b
0.0 560.0
b
661.4
b
κ
0.72 (0.06) 0.40 (0.12) 0.42 (0.06) 0.77 (0.06)
AUC
0.83 (0.05) 0.70 (0.13) 0.68 (0.05) 0.86 (0.05)
OR (95% CI)
141.6 (114.7-174.8) 31.0 (24.4-39.4) 12.0 (10.0-13.7) 229.1 (181.1-289.7)
SN
67.6 (5.3) 42.5 (13.6) 41.7 (5.9) 72.6 (5.1)
SP
98.5 (0.8) 97.7 (0.9) 94.4 (1.9) 98.9 (0.7)
PPV
95.5 (2.2) 42.7 (11.9) 70.9 (6.2) 96.7 (1.9)
NPV
86.9 (3.8) 97.7 (1.1) 83.1 (4.4) 88.7 (3.5)
Data are shown as mean (SEM), except odds ratio (OR) and 95% condence interval of the OR (95% CI).
DSM-IV-TR refers to Diagnostic and Statistical Manual, Fourth Edition, Text Revision; ICD-10, International
Classication of Diseases-10; RDC/ICSD-2, research diagnostic criteria and International Classication
of Sleep Disorders-2; AUC, area under the receiver operating characteristic curve; SN, sensitivity; SP,
specicity; PPV, positive predictive value; NPV, negative predictive value.
a
The
data were weighted to adjust for the oversampling of respondents classied in the fully structured
America Insomnia Survey interviews as meeting criteria for insomnia or subthreshold insomnia;
b
Signicant
at the 0.05 level, 2-sided test.
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
reliability is generally found to be lower for insomnia than
other sleep complaints in psychometric studies,
6
as well as for
the fact that reports of more qualitative symptoms of insomnia,
such as the restorative value of sleep and daytime functioning,
are usually found to be less stable in test-retest studies than are
more quantitative reports of sleep-problem frequency and dura-
tion.
5,39
Our results regarding the short-term test-retest reliabil-
ity of BIQ symptoms are not entirely consistent with the latter
results, though, as the test-retest correlations for BIQ reports of
daytime impairment (0.87-0.88) are as high as those for reports
of more quantitative symptoms. Indeed, the majority of BIQ
items have good to excellent test-retest reliability. The few cas-
es in which test-retest reliability is unacceptably low, as noted
in the results section, are due either to sparse data, sensitivity
at the upper end of a wide response range, or response incon-
sistency among respondents with subthreshold symptoms. We
also found that mean values of some items were signicantly
lower on retest, which suggests that the test-retest paradigm un-
derestimates true BIQ reliability.
As noted in the introduction, only limited psychometric in-
formation is available on the validity of other fully structured
insomnia scales. Much of this information is based on patient
samples,
5-9
which cannot be compared with the results in the
current report because the severity of insomnia is almost cer-
tainly greater in clinical than in community samples. Several
other studies have evaluated the validity of various fully struc-
tured insomnia scales in community samples, compared with
diagnoses based on clinical interviews.
10-12
Estimates of AUC
in those studies were in the range 0.81 to 1.0. However, all of
those studies used super-normal control groups. As shown in
our comparison of validity statistics based on the full BIQ clini-
cal reappraisal sample and the subsample that excluded BIQ
noncases who reported sleep problems, the use of super-normal
controls inates estimates of diagnostic concordance. The exact
magnitude of this ination in previous studies cannot be deter-
DISCUSSION
Unlike other sleep conditions, such as breathing-related and
circadian rhythm disorders, that are conrmable using relative-
ly objective methods, chronic or transient insomnia is primarily
diagnosed by self-reported sleep history obtained during clini-
cal interview.
37
Indeed, American Academy of Sleep Medicine
best-practice guidelines caution against diagnosing insomnia
using objective indices such as polysomnography or actigra-
phy because of substantial night-to-night variability in sleep
symptoms and “rst-night” phenomena. The Academy recom-
mends instead that routine insomnia diagnoses be grounded in
self-reported sleep history.
38
This inherently subjective nature
of insomnia presumably contributes to the fact that test-retest
Table 3—The effect of using super-normal controls versus normal
controls in the evaluation of consistency of diagnoses based on the Brief
Insomnia Questionnaire with diagnoses based on clinical interviews in
the weighted America Insomnia Scale clinical reappraisal sample
a
Cohen’s κ
Criteria
DSM-IV-TR ICD-10 RDC/ICSD-2 Any
SNC 0.89 (0.04) 0.53 (0.16) 0.64 (0.08) 0.91 (0.04)
NC 0.72 (0.06) 0.40 (0.12) 0.42 (0.06) 0.77 (0.06)
Area under the receiver operating characteristic curve
SNC 0.95 (0.11) 0.92 (0.23) 0.84 (0.07) 0.95 (0.13)
NC 0.83 (0.05) 0.70 (0.13) 0.68 (0.05) 0.86 (0.05)
Sensitivity
SNC 96.8 (2.2) 100.0 (0.0) 93.7 (4.4) 97.0 (2.1)
NC 67.6 (5.3) 42.5 (13.6) 41.7 (5.9) 72.6 (5.1)
Specity
SNC 92.2 (3.9) 84.9 (4.8) 73.6 (6.1) 93.8 (3.6)
NC 98.5 (0.8) 97.7 (0.9) 94.4 (1.9) 98.9 (0.7)
Positive predictive value
SNC 95.5 (2.2) 42.7 (12.0) 70.9 (6.2) 96.7 (1.9)
NC 95.5 (2.2) 42.7 (11.9) 70.9 (6.2) 96.7 (1.9)
Negative predictive value
SNC 94.4 (3.9) 100.0 (0.0) 94.4 (3.9) 94.4 (3.9)
NC 86.9 (3.8) 97.7 (1.1) 83.1 (4.4) 88.7 (3.5)
(n)
b
(113) (52) (91) (117)
DSM-IV-TR refers to Diagnostic and Statistical Manual, Fourth Edition,
Text Revision; ICD-10, International Classication of Diseases-10; RDC/
ICSD-2, research diagnostic criteria and International Classication of
Sleep Disorders-2; SNC, results based on the analysis of Brief Insomnia
Questionnaire (BIQ) cases compared to super-normal controls; NC,
results based on the full sample, which includes normal controls.
a
Data are displayed as mean (SEM). The data were weighted in exactly
the same way as in Table 2, but the sample excluded respondents who
reported sleep problems at least 2 nights a week for at least 1 month in the
BIQ who did not meet diagnostic criteria for insomnia in the BIQ according
to the diagnostic system specied in the row heading. This exclusion
resulted in the BIQ noncases consisting exclusively of BIQ SNC.
b
The sample sizes are those for the analyses based on the SNC data.
The sample size for analyses based on the data from the NC data is
consistently n = 203 across outcomes. Sample size varies across
outcomes for the SNC data because the excluded cases were conned
to respondents who did not meet criteria for insomnia according to the
diagnostic system specied in the specic row heading.
Table 4—Comparisons of AUC in predicting clinical diagnoses based
on the dichotomous Brief Insomnia Questionnaire classication and of
continuous predicted probabilities of clinical diagnoses based on Brief
Insomnia Questionnaire item-level data in the clinical reappraisal sample
of 203 adults
Criteria
AUC
a
Dichotomous Continuous
DSM-IV-TR 0.83 (0.05) 0.92 (0.06)
ICD-10 0.70 (0.13) 0.95 (0.19)
RDC/ICSD-2 0.68 (0.05) 0.92 (0.06)
Any 0.86 (0.05) 0.94 (0.06)
DSM-IV-TR refers to Diagnostic and Statistical Manual, Fourth Edition,
Text Revision; ICD-10, International Classication of Diseases-10; RDC/
ICSD-2, research diagnostic criteria and International Classication of
Sleep Disorders-2.
a
Dichotomous area under the receiver operating characteristic curve
(AUC) values are for the dichotomous Brief Insomnia Questionnaire
(BIQ) diagnostic classications; Continuous AUC values are for the
continuous predicted probabilities of clinical diagnoses derived from
logistic regression equations using BIQ diagnoses and BIQ item-level
data to predict clinical diagnoses. Data are displayed as mean (SEM).
SLEEP, Vol. 33, No. 11, 2010
1547
Reliability & Validity of the BIQ in the AIS—Kessler et al
be a valid mode of clinical assessment for other DSM disor-
ders,
19-21
it is conceivable that the accuracy of clinical diagnoses
would have been improved by in-person assessment. If so, con-
cordance between diagnoses based on the BIQ and those based
on clinical interviews would presumably have been higher than
reported are here. A related limitation is that the accuracy of
clinical diagnoses might have been improved by including
sleep diaries, polysomnography, or other additional information
to supplement clinical interviews. This limitation highlights the
fact that, even though we used the word validation to character-
ize the current investigation, the fact that the clinical diagnoses
cannot be taken as perfectly valid means that the estimates of
concordance reported here should be considered lower-bound
estimates on the validity of the BIQ. Even if accepted on face
value, rather than as lower-bound estimates, though, the results
demonstrate that the BIQ accurately estimates the prevalence
and correlates of insomnia in the AIS.
ACKNOWLEDGMENTS
The America Insomnia Survey (AIS) was conceived of and
funded by Sano-Aventis (SA). The study was designed and su-
pervised by a 4-member Executive Committee of academic ex-4-member Executive Committee of academic ex--member Executive Committee of academic ex-
perts in insomnia (Goran Hajak, Thomas Roth, James K. Walsh)
and psychiatric epidemiology (Ronald C. Kessler). The Executive
Committee developed the study protocol and survey instrument,
supervised data collection, and is responsible for planning data
analyses, interpreting results, and publishing study reports. An
AIS Steering Committee made up of both academics and repre-
sentatives from SA provides consultation to the Executive Com-
mittee. Steering Committee members include experts in sleep
mined because it depends on how extreme the exclusion crite-
ria were in dening super-normal subjects. As a result, there is
no principled way to compare the validity estimates in earlier
studies with those in the current report. Nor is it legitimate to
compare the estimates in earlier reports with the BIQ estimates
based on comparisons with super-normal control subjects be-
cause we have no way of knowing if the exclusion rules used
in our sampling scheme were comparable with those used in
earlier studies.
While these issues of noncomparability make it impossible
to evaluate the comparative performance of the BIQ versus
other fully structured insomnia measures such as the Pittsburgh
Sleep Quality Index
5
or SDQ,
32
our results show clearly that
diagnoses based on dichotomous BIQ classications have sub-
stantial concordance with clinical diagnoses of insomnia based
on DSM-IV-TR and any criteria, fair to moderate concordance
with clinical diagnoses based on RDC/ICSD-2 criteria, and fair
concordance with diagnoses based on ICD-10 criteria. In addi-
tion, we found that probability-of-diagnosis measures based on
BIQ item-level data have consistently excellent AUCs (0.92-
0.95) across all diagnostic systems. This result is important be-
cause, unlike the situation in clinical practice, there is no need
in epidemiologic studies to classify individual respondents di-
chotomously as either denite cases or denite noncases.
A limitation of the current study is that the survey coopera-
tion rate was only 65.0%. This low rate might indicate the ex-
istence of bias in the sample composition, which could distort
estimates of instrument validity. Another limitation is that the
clinical reappraisal interviews were carried out over the tele-
phone. Although telephone administration has been shown to
Figure 1—Receiver operating characteristic curves for America Insomnia Survey-based predicted probabilities of insomnia based on different diagnostic
systems in the clinical reappraisal sample of 203 adults. DSM-IV-TR refers to Diagnostic and Statistical Manual, Fourth Edition, Text Revision; ICD-10,
International Classication of Diseases-10; research diagnostic criteria and International Classication of Sleep Disorders-2, RDC/ICSD-2.
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
1- Specificity
Sensitivity
DSM-IV-TR
ICD-10
RDC/ICSD-2
Any
Diagnostic System
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
Transcept, and Wyeth; and has received research support from
Actelion, Affectis, Astra-Zeneca, BrainLab, Daimler Benz, Es-
sex, GlaxoSmithKline, Lundbeck, Neurim, NeuroBiotec, Neu-
rocrine, Novartis, Organon, Sano-Aventis, Schwarz, Sepracor,
Takeda, UCB, Volkswagen, Weinmann, and Wyeth. Mr. Lakoma
is an employee of the Department of Health Care Policy at Har-
vard Medical School. His group has received research funding
from Pzer, Sano Aventis, Shire Development, and Janssen
Pharmceutica, N.V. Lakoma has no nancial interest in these or-
ganizations. Dr. Roth has served as a consultant for Abbott, Ac-
cadia, Acogolix, Acorda, Actelion, Addrenex, Alchemers, Alza,
Ancel, Arena, AstraZeneca, Aventis, AVER, Bayer, BMS, BTG,
Cephalon, Cypress, Dove, Eisai, Elan, Eli Lilly, Evotec, Forest,
GlaxoSmithKline, Hypnion, Impax, Intec, Intra-Cellular, Jazz,
Johnson and Johnson, King, Lundbeck, McNeil, MediciNova,
Merck, Neurim, Neurocrine, Neurogen, Novartis, Orexo, Or-
ganon, Otsuka, Prestwick, Proctor and Gamble, Pzer, Purdue,
Resteva, Roche, Sano, Schoering-Plough, Sepracor, Servier,
Shire, Somaxon, Syrex, Takeda, TransOral, Vanda, Vivometrics,
Wyeth, Yamanuchi, and Xenoport; has participated in speaking
engagements for Cephalon, Sano, and Sepracor; and has re-
ceived research support from Aventis, Cephalon, GlaxoSmith-
Kline, Merck, Neurocrine, Pzer, Sano, Schoering-Plough,
Sepracor, Somaxon, Syrex, Takeda, TransOral, Wyeth, and
Xenoport. Ms. Sampson is an employee of the Department of
Health Care Policy at Harvard Medical School. Her group has
received research funding from Pzer, Sano-Aventis, Shire
Development, Inc., and Janssen Pharmceutica, N.V. Sampson
has no nancial interest in these organizations. Dr. Shillington
is employee of a company (Epi-Q) that has received funding
from Astra-Zeneca, Pzer, Cephalon, Daichii Samkyo, Takeda,
Biogen, Sano-Aventis, Abbot Laboratories, Merck, Novartis,
Shire, Affymax, and Adolor. Her compensation is limited to her
salary. She owns stock in Epi-Q. Ms. Stephenson is an employ-
ee of HealthCore, Inc., a research and consulting organization.
All of her research activities are industry sponsored. Dr. Walsh
has consulted for Pzer, Sano-Aventis, Cephalon, Schering-
Plough/Organon, Neurocrine, Takeda America, Actelion, Sepra-
cor, Jazz, Respironics, Transcept, Neurogen, GlaxoSmithKline,
Somaxon, Eli Lilly, Evotec, Merck, Kingsdown, Vanda, Ventus,
and Somnus. Research support has been provided to his insti-
tution by Pzer, Merck, Somaxon, Evotec, Actelion, Vanda,
Neurogen, Sano-Aventis, Ventus, Respironics, and Jazz Phar-
maceuticals. Dr. Zammit has received research support from Ac-
telion, Ancile, Arena, Aventis, Boehringer-Ingelheim, Cephalon,
Elan, Epix, Evotec, Forest, GlaxoSmithKline, H. Lundbeck A/S,
King, Merck, National Institute of Health, Neurim, Neurocrine
Biosciences, Neurogen, Organon, Orphan Medical, Pzer, Res-
pironics, Sano-Aventis, Schering-Plough, Sepracor, Somaxon,
Takeda, Targacept, Transcept, UCB Pharma, Predix, Vanda, and
Wyeth. He has been a consultant for Actelion, Alexza, Arena,
Aventis, Biovail, Boehringer Ingelheim, Cephalon, Elan, Eli
Lilly, Evotec, Forest, GlaxoSmithKline, Jazz, King Pharmaceu-
ticals, Ligand, McNeil, Merck, Neurocrine Biosciences, Orga-
non, Pzer, Renovis, Sano-Aventis, Select Comfort, Sepracor,
Shire, Somnus, Takeda, Vela, and Wyeth. He has ownership or
directorship status in Clinilabs, Inc., Clinilabs IPA, Inc., and
Clinilabs Physician Services, PC. Dr. Shahly reports no conict
of interest.
(Diego Garcia, Damien Leger, Charles Morin, Gary Zammit),
psychiatric epidemiology (Bruno Falissard), and health services
research (Alicia Shillington, Judith Stephenson). SA representa-
tives on the Steering Committee include Catherine Coulouvrat,
Gilles Perdriset, Christophe Candelas, Françoise Dellatolas,
Lewis Warrington, Adam Winseck, and Brian Seal. The main
AIS survey was carried out by DataStat, Inc. The AIS clinical
reappraisal study was carried out by Clinilabs, Inc. A Publica-
tions Committee made up of the Executive Committee and health
services research and SA representatives from the Steering Com-
mittee is responsible for overseeing AIS publication plans. Data
analysis for the current report was carried out at Harvard Medical
School under the supervision of Ronald Kessler. The rst draft
of the manuscript was prepared by Kessler and the other Har-
vard Medical School coauthors. The remaining coauthors col-
laborated in designing the data-analysis plan, interpreting results,
providing critical comments on the rst draft, and making revi-
sions. Authors are fully responsible for all content and editorial
decisions. Although a draft of the manuscript was submitted to
SA for review and comment prior to submission, this was with
the understanding that comments would be no more than advi-
sory. SA played no role in data collection or management other
than in posing the initial research question, providing operational
and nancial support, and facilitating communications among
collaborators. SA played no role in data analysis, interpretation
of results, or preparation of the manuscript. The authors thank
Marcus Wilson and his staff at HealthCore, Inc., for recruiting the
AIS sample and for the use of the HealthCore research environ-
ment; Marielle Weindorf and her staff at DataStat, Inc., for AIS
eldwork; and Jon Freeman at Clinilabs, Inc., and his panel of
interviewers, Drs. Melanie Means, Angela Randazzo, Rebecca
Scott, Stephanie Silberman, Elaine Wilson, and Rochelle Zozula,
for carrying out the clinical reappraisal study. The AIS interview
schedule and a complete list of AIS publications can be found
at http://www.hcp.med.harvard.edu/wmh/afliated_studies.php.
DISCLOSURE STATEMENT
Sano-Aventis provided support for this study. Dr. Kessler
has been a consultant or a member of an advisory board for
Eli Lilly, GlaxoSmithKline, Kaiser Permanente, Pzer, Sano-
Aventis, Shire Pharmaceuticals, and Wyeth-Ayerst and has had
research support for his epidemiologic studies from Bristol-
Myers Squibb, Eli Lilly, GlaxoSmithKline, Johnson & Johnson
Pharmaceuticals, Ortho-McNeil Pharmaceuticals, Pzer, and
Sano-Aventis. Dr. Coulouvrat is an employee of Sano-Aven-
tis. Dr. Hajak has been a consultant or a member of an advisory
board for Actelion, Affectis, Astellas, Astra-Zeneca, Bayer Vi-
tal, Bristol-Meyers Squibb, Boehringer Ingelheim, Cephalon,
Essex, Gerson Lerman Group Council of Healthcare Advisors,
GlaxoSmithKline, Janssen-Cilag, Lundbeck, McKinsey, Meda-
Corp, Merck, Merz, Mundipharm, Network of Advisors, Neu-
rim, Neurocrine, Novartis, Organon, Orphan, Pzer, Pharmacia,
Proctor & Gamble, Purdue, Sano-Aventis, Schering-Plough,
Sepracor, Servier, Takeda, Transcept, and Wyeth; has participat-
ed in speaking engagements for Actelion, Astra-Zeneca, Bayer
Vital, Bristol-Meyers Squibb, Boehringer Ingelheim, Cephalon,
EuMeCom, Essex, GlaxoSmithKline, Janssen-Cilag, Eli Lilly,
Lundbeck, Merck, Merz, Neurim, Novartis, Organon, Pzer,
Pharmacia, Sano-Aventis, Schering-Plough, Servier, Takeda,
SLEEP, Vol. 33, No. 11, 2010
1549
Reliability & Validity of the BIQ in the AIS—Kessler et al
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SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
SUPPLEMENTAL MATERIAL—Brief Insomnia Questionnaire
SL1. How many nights out of 7 in a typical week do you have problems falling asleep?
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
_ NUMBER OF NIGHTS IN A TYPICAL WEEK
0. NONE/NEVER/LESS THAN 1 -------> QSL4
7. EVERY NIGHT/ALL OF THEM
DK ----------------------------------------------> QSL4
SL3. How long does it usually take you to fall asleep on the nights you have a problem falling asleep?
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
HR- HOURS < three-quarters, three-fourths = 3/4 >
MI- MINUTES < one-third = 1/3 >
< two-thirds = 2/3 >
SL4. How many nights out of 7 in a typical week do you have problems STAYING asleep throughout the night?
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
(IF NEEDED: “Please include waking up for any reason including going to the bathroom, feeding a baby, taking care of children, or taking care of a
pet.”)
_ NUMBER OF NIGHTS IN A TYPICAL WEEK
0. NONE/NEVER/LESS THAN 1 -------> QSL8
7. EVERY NIGHT/ALL OF THEM
DK ----------------------------------------------> QSL8
SL5.1. How much time do you usually spend awake at night on the nights you have trouble sleeping?
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
HR- HOURS < three-quarters, three-fourths = 3/4 >
MI- MINUTES < one-third = 1/3 >
< two-thirds = 2/3 >
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
SL6. How many times per night do you usually wake up during [that night/those [QSL4] nights]?
(IF NEEDED: “On the nights when you have a problem staying asleep, how many times do you usually wake up in the night?”)
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
__ NUMBER OF TIMES YOU WAKE UP DURING THE NIGHT
08. 8 OR MORE TIMES
DK
SL7. How long does it usually take you to get back to sleep once you wake up at night?
(IF R NEVER FALLS BACK TO SLEEP, ENTER 999 MI)
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
HR- HOURS < three-quarters, three-fourths = 3/4 >
MI- MINUTES < one-third = 1/3 >
< two-thirds = 2/3 >
SL8. How many mornings out of 7 in a typical week do you wake up before your alarm clock goes off?
(IWER: IF R SAYS, “I DON’T HAVE AN ALARM CLOCK” PROBE: “How many mornings (out of 7 in a typical week) do you wake up before you want
to?”)
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
_ NUMBER OF NIGHTS IN A TYPICAL WEEK
0. NONE/NEVER/LESS THAN 1 -----> QSL11
7. EVERY NIGHT/ALL OF THEM
DK --------------------------------------------> QSL11
SL10. How much earlier than you want do you wake up on those days?
(IF NEEDED: “On the days you wake up too early, how much earlier do you wake up?”)
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
HR- HOURS < three-quarters,three-fourths = 3/4 >
MI- MINUTES < one-third = 1/3 >
< two-thirds = 2/3 >
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
SL11. How many mornings out of 7 in a typical week do you wake up still feeling tired or unrested?
(IWER: IF R GIVES A RANGE OR SAYS “IT DEPENDS”, PROBE: “In general”)
(IWER: IF A RANGE IS STILL GIVEN AFTER PROBE, ENTER THE LOWER NUMBER)
_ NUMBER OF MORNINGS IN A TYPICAL WEEK
0. NONE/NEVER/LESS THAN 1 -------- > CK.SL19
7. EVERY MORNING/ALL OF THEM
DK -----------------------------------------------> CK.SL19
SL13. How would you rate the severity of your problem waking up feeling tired or unrested? Would you say it’s...
(READ LIST)
(IF R SAYS “IT DEPENDS”, PROBE: “In general”)
1. MILD,
2. MODERATE,
3. SEVERE, OR
4. VERY SEVERE?
DK (DO NOT READ)
--------------------------------------------------------------------------------------------------------------------------------
CK.SL19: Must have at least 1 night of any of the above problems to continue; if not skip out of remaining BIQ questions
--------------------------------------------------------------------------------------------------------------------------------
SL20. About how many nights out of 7 in a typical week do you have a problem [(either)/falling asleep(, or)/staying asleep(, or)/waking too early(, or)/feeling
tired and unrested in the morning]?
(IF R SAYS “IT DEPENDS”, PROBE: “In general”)
_ NUMBER OF NIGHTS IN A TYPICAL WEEK
0. NONE/NEVER/LESS THAN 1 ---> QSL22.4
7. EVERY NIGHT/ALL OF THEM
DK
SL21. For how many weeks, months, or years have you had [a problem/either of these problems/at least one of these problems]?
(IF “DK”, PROBE: “Has it gone on for at least 4 weeks?” and IF “YES”, ENTER “1 MO”)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
DY- DAYS < three-quarters, three-fourths = 3/4 >
WK- WEEKS < one-third = 1/3 >
MO- MONTHS < two-thirds = 2/3 >
YR- YEARS
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Reliability & Validity of the BIQ in the AIS—Kessler et al
INTRO.QSL28
The next questions are about how your sleep [problem has/problems have] affected your daytime functioning in various ways over the PAST 30 DAYS.
SL(28-35). [First,/(How about)]
28. “reduced motivation”
29. “performance at work, school, or social activities”
30. “making errors or having accidents”
31. “irritability, nerves, or mood disturbance”
32. “daytime attention, concentration, or memory problems”
33. “daytime fatigue”
34. “daytime sleepiness”
35. “tension headaches or digestive problems”
?
(HOW MUCH DIFFICULTY have you had with this because of your sleep [problem/problems] over the PAST 30 DAYS?)
(Would you say...)
(READ LIST IF NECESSARY)
(IF R SAYS “IT DEPENDS”, PROBE: “In general”)
1. NONE,
2. MILD,
3. MODERATE, OR
4. SEVERE DIFFICULTY?
DK (DO NOT READ)
SL36A. (How about)
concerns or worries about your sleep?
(HOW MUCH DIFFICULTY do you have with this because of your sleep [problem/problems]?)
(Would you say...)
(READ LIST IF NECESSARY)
(IF R SAYS “IT DEPENDS”, PROBE: “In general”)
1. NONE,
2. MILD,
3. MODERATE, OR
4. SEVERE?
DK (DO NOT READ)
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
SL36B. How worried or distressed are you about your sleep problems? Would you say...
(READ LIST)
1. NOT AT ALL,
2. A LITTLE,
3. SOMEWHAT,
4. MUCH, OR
5. VERY MUCH?
DK (DO NOT READ)
INTRO.QSL41
The next questions are about how sleep problems interfered with your daily activities during the past 4 weeks.
SL(41-44). [Using a 0 to 10 scale, where 0 means NO INTERFERENCE and 10 means VERY SEVERE INTERFERENCE,/(Using the same 0 to 10 scale,)]
41. “what number describes how much your sleep problems interfered with your home management, like cleaning, shopping, and taking care of
your home”
42. “how much did problems with your sleep interfere with your ability to work”
43. “how much did problems with your sleep interfere with your social life”
44. “how much did problems with your sleep interfere with your close personal relationships”
?
[(You can use any number between 0 and 10 to answer.)/(Again, you can use any number between 0 and 10 to answer.)]
(IF NEEDED: “0 means NO INTERFERENCE and 10 means VERY SEVERE INTERFERENCE.”)
(IF NEEDED: “In general, in the past 4 weeks.”)
00 01 02 03 04 05 06 07 08 09 10
NO VERY SEVERE
INTERFERENCE INTERFERENCE
DK
SS2. About how much time do you typically spend in bed the night before a work day, including time spent watching TV, reading, talking to your partner,
trying to sleep, AND SLEEPING?
(IF R SAYS LESS THAN 5 HOURS: “Please include time sleeping.”)
(IF R DOES NOT WORK: “Please think about a typical weekday night.”)
(IF R SAYS “IT DEPENDS”, PROBE: “In general, on average”)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
HR- HOURS < three-quarters, three-fourths = 3/4 >
MI- MINUTES < one-third = 1/3 >
< two-thirds = 2/3 >
SLEEP, Vol. 33, No. 11, 2010
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Reliability & Validity of the BIQ in the AIS—Kessler et al
SS3. About how much time do you typically spend in bed altogether on a WEEKEND night?
(IF NEEDED: “Including time spent watching TV, reading, talking to your partner, trying to sleep, and sleeping”)
(IF NEEDED: “Please think about a typical Saturday night.”)
(IF R SAYS “IT DEPENDS”, PROBE: “In general, on average”)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
HR- HOURS < three-quarters, three-fourths = 3/4 >
MI- MINUTES < one-third = 1/3 >
< two-thirds = 2/3 >
INTRO.QSS4
Let’s focus on the [QSS2 hours] you spend in bed on a WEEK-night.
SS(4-6). [About how much of that time do you typically spend.../And about how many of the [QSS2 hours] do you typically spend...]
4. “either watching TV, reading, or talking to your partner”
5. “lying in bed trying to get to sleep but not sleeping”
6. “ACTUALLY sleeping”
(IF R DOES NOT WORK: “Please think about a typical weekday night.”)
(IWER: IF R SAYS “NEVER” ENTER ‘0 HR’)
(IF R SAYS “IT DEPENDS”, PROBE: “On average, on a typical WORK-DAY”)
#______ < one-quarter, one-fourth = 1/4 >
DK < one-half = 1/2 >
HR- HOURS < three-quarters, three-fourths = 3/4 >
MI- MINUTES < one-third = 1/3 >
< two-thirds = 2/3 >
INTRO.QSS15
The next question is about how much your sleep problems are caused by
the place you sleep being too light, too noisy, too hot or cold, or
uncomfortable.
SS15A. How much do you think your sleep problems are caused by problems with the place you sleep? Would you say...
(READ LIST)
(IF R SAYS “IT DEPENDS”, PROBE: “On average”)
1. NOT AT ALL,
2. A LITTLE,
3. SOME,
4. A LOT, OR
5. TOTALLY?
DK (DO NOT READ)
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SS16. Some people have sleep problems because they either have to get up very early, stay up late, or get up in the night because of their job or
because of having a baby or a sick person who needs their help.
How much do you think your sleep problems are caused by these kinds of demands on your time? Would you say...
(READ LIST)
(IF R SAYS “IT DEPENDS”, PROBE: “On average”)
1. NOT AT ALL,
2. A LITTLE,
3. SOME,
4. A LOT, OR
5. TOTALLY?
DK (DO NOT READ)
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Reliability & Validity of the BIQ in the AIS—Kessler et al
DSM-IV-TR Diagnostic Criteria for Primary Insomnia
A. The predominant complaint is difculty initiating or maintaining sleep, or nonrestorative sleep, for at least 1 month.
A1.1. The predominant complaint is difculty initiating sleep
SL1 = 3-7 (problems getting to sleep ≥ 3 and ≤ 7 nights a week) AND
SL3 ≥ 30 minutes (it takes 30 or more minutes to get to sleep those nights)
OR
A1.2. The predominant complaint is difculty maintaining sleep
A1.2a. Waking multiple times (waking 3 or more times at night)
SL4 = 3-7 (problems staying asleep ≥ 3 and ≤ 7 nights a week) AND EITHER
[(SL6 ≥ 3: waking 3 or more times)
OR
A1.2b. Taking a long time to get back to sleep after awakening at night (30 or more minutes awake)
SL4 = 3-7 (problems staying asleep ≥ 3 and ≤ 7 nights a week) AND EITHER
[(SL5.1 ≥ 30 minutes awake at night) OR (SL7: Number of minutes it takes to get back to sleep) x (SL6: Number of awakenings) ≥ 30 minutes]
OR
A1.2c. Waking too early in the AM (30 or more minutes early)
SL8 = 3-7 (problems waking too early in the morning ≥ 3 and ≤ 7 days a week) AND
SL10 ≥ 30 minutes (R wakes 30 or more minutes early those mornings)
OR
A1.3. The predominant complaint is nonrestorative sleep
SL11 = 3-7 (problems feeling unrefreshed in the morning ≥ 3 and ≤ 7 days a week) AND
SL13 = 2-4 (the severity of the problem waking up feeling nonrefreshed is either moderate, severe, or very severe) AND
SS5+SS6 > = 7 hours (R has adequate opportunity for sleep) AND
A1.1 = No and A1.2a = No and A1.2b = No and A1.2c = No (R doesn’t have any other sleep problem)
AND
A2. The complaint has lasted at least one month
SL21 ≥ 30 days (For how many weeks, months, or years have you had at least one of these problems?)
B. The sleep disturbance (or associated daytime fatigue) causes clinically signicant distress or impairment in social, occupational, or other important
areas of functioning.
SUPPLEMENTAL MATERIAL—Scoring Algorithms
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We created a count of responses to all the daytime impairment items to operationalize this criterion.
SUM the number of responses in the SL28-34 series that were coded 3-4 plus whether or not SL35 was coded 4 plus whether or not 36A was coded 3-4 plus
whether or not SL36B was coded 4-5 (you only get 1 point if either 36A or 36B was in the range) plus the sum of the SL41-44 series that were coded 7-10.
Impairment is initialized to zero.
28. reduced motivation mod/sev - If SL28 = 3 or 4 then impairment = impairment + 1
29. reduced performance at work, school, or social activities mod/sev - IF SL29 = 3 or 4 then impairment = impairment + 1
30. errors or accidents mod/sev - If SL30 = 3 or 4 then impairment = impairment + 1
31. irritability, nerves, mood disturbance mod/sev - If SL31 = 3 or 4 then impairment = impairment + 1
32. daytime attention, concentration, or memory problems mod/sev - If SL32 = 3 or 4 then impairment = impairment + 1
33. daytime fatigue mod/sev - If SL33 = 3 or 4 then impairment = impairment + 1
34. daytime sleepiness mod/sev - If SL34 = 3 or 4 then impairment = impairment + 1
35. tension headaches or digestive problems SEVERE (NOT MOD/SEV) - If SL35 = 4 then impairment = impairment + 1
36A. concerns or worries about your sleep mod/sev
36B. worried or distressed about sleep problems much/very much – If SL36a OR SL36b = 3 or 4 then impairment = impairment+1
41. sleep probs interfered with home management 7-10/0-10 - If SL41 ≥ 7 then impairment = impairment +1
42. sleep probs interfered with ability to work 7-10/0-10 - If SL42 ≥ 7 then impairment = impairment +1
43. sleep probs interfered with social life 7-10/0-10 - If SL43 ≥ 7 then impairment = impairment +1
44. sleep probs interfered with close relationships 7-10/0-10 - If SL44 ≥ 7 then impairment = impairment +1
We say that Criterion B is met if impairment ≥ 2.
C. The sleep disturbance does not occur exclusively during the course of narcolepsy,
breathing-related sleep disorder, circadian rhythm sleep disorder, or parasomnia.
NOT OPERATIONALIZED
D. The disturbance does not occur exclusively during the course of another mental
disorder (e.g., major depressive disorder, generalized anxiety disorder, a delirium).
NOT OPERATIONALIZED
E. The disturbance is not due to the direct physiological effects of a substance.
NOT OPERATIONALIZED
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ICD-10 Diagnostic Criteria for Non-Organic Insomnia
A. The complaint is either of difculty falling asleep or maintaining sleep, or of poor quality sleep;
Same items as in DSM-IV
B. The sleep disturbance has occurred at least three times per week for at least 1 month;
The 3 days a week part is met in the coding above for Criterion A
The 1 month part is operationalized in the same way as DSM-IV, namely:
SL21 ≥ 30 days (For how many weeks, months, or years have you had at least one of these problems?)
C. There is preoccupation with the sleeplessness and excessive concern over its consequences at night and during the day;
SL36A = 3-4 (R has moderate or severe concerns about the sleep problems)
OR
SL36B = 4-5 (R has much or very much worries or distress about the sleep problems)
D. The unsatisfactory quantity and/or quality of sleep either causes marked distress or interferes with ordinary activities in daily living.
We created a count of responses to all the daytime impairment items to operationalize this criterion.
SUM the number of responses in the SL28-34 series that were coded 3-4 plus whether or not SL35 was coded 4 plus the sum of the SL41-44 series that were
coded 7-10.
Impairment is initialized to zero.
28. reduced motivation mod/sev - If SL28 = 3 or 4 then impairment = impairment + 1
29. reduced performance at work, school, or social activities mod/sev - IF SL29 = 3 or 4 then impairment = impairment + 1
30. errors or accidents mod/sev - If SL30 = 3 or 4 then impairment = impairment + 1
31. irritability, nerves, mood disturbance mod/sev - If SL31 = 3 or 4 then impairment = impairment + 1
32. daytime attention, concentration, or memory problems mod/sev - If SL32 = 3 or 4 then impairment = impairment + 1
33. daytime fatigue mod/sev - If SL33 = 3 or 4 then impairment = impairment + 1
34. daytime sleepiness mod/sev - If SL34 = 3 or 4 then impairment = impairment + 1
35. tension headaches or digestive problems SEVERE (NOT MOD/SEV) - If SL35 = 4 then impairment = impairment + 1
41. sleep probs interfered with home management 7-10/0-10 - If SL41 ≥ 7 then impairment = impairment +1
42. sleep probs interfered with ability to work 7-10/0-10 - If SL42 ≥ 7 then impairment = impairment +1
43. sleep probs interfered with social life 7-10/0-10 - If SL43 ≥ 7 then impairment = impairment +1
44. sleep probs interfered with close relationships 7-10/0-10 - If SL44 ≥ 7 then impairment = impairment +1
We say that Criterion D is met if impairment ≥ 2
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Research Diagnostic Criteria for Insomnia Disorder
A. The individual reports one or more of the following sleep related complaints: difculty initiating sleep, difculty maintaining sleep, waking up too
early, or sleep that is chronically non-restorative or poor in quality.
We operationalize this in exactly the same way as the comparable DSM-IV criterion (i.e., using the 3-day rule, the 30 minutes for getting to sleep, the 30 minutes
for waking in the night and waking two early, and the ≥ 3 rule for number of times waking in the night (waking ≥ 3 and being awake ≥ 30 minutes are alternatives
for the same sub-criterion)).
B. The above sleep difculty occurs despite adequate opportunity and circumstances for sleep.
SS15a NOT EQUAL 4-5 (R did NOT say that his sleep problems are caused a lot or totally by problems with the place he sleeps)
AND
SS16 NOT EQUAL 4-5 (R did NOT say that his sleep problems are caused a lot or totally by demands on his time that require him to sleep irrregularly)
C. At least one of the following forms of daytime impairment related to the nighttime sleep difculty is reported by the individual:
1. Fatigue (SL33)/Malaise (NOT OPERATIONALIZED);
2. Attention, concentration, or memory impairment;(SL32)
3. Social/Vocational dysfunction or poor school performance (SL29, 41, 42, 43, 44);
4. Mood disturbance/Irritability (SL31);
5. Daytime sleepiness (SL34);
6. Motivation (SL28)/Energy (SL33)/Initiative reduction (SL28);
7. Proneness for errors/accidents at work or while driving (SL30);
8. Tension headaches, and/or GI symptoms in response to sleep loss (SL35);
9. Concerns or worries about sleep (SL36A/36B).
There is a one-to-one map (with the exception of malaise, which is not operationalized) of Criterion C symptoms to the SL28-44 series, as shown above. The
thresholds used are the same as in the DSM operationalization, namely:
Impairment is initialized to zero.
28. reduced motivation mod/sev - If SL28 = 3 or 4 then impairment = impairment + 1
29. reduced performance at work, school, or social activities mod/sev - IF SL29 = 3 or 4 then impairment = impairment + 1
30. errors or accidents mod/sev - If SL30 = 3 or 4 then impairment = impairment + 1
31. irritability, nerves, mood disturbance mod/sev - If SL31 = 3 or 4 then impairment = impairment + 1
32. daytime attention, concentration, or memory problems mod/sev - If SL32 = 3 or 4 then impairment = impairment + 1
33. daytime fatigue mod/sev - If SL33 = 3 or 4 then impairment = impairment + 1
34. daytime sleepiness mod/sev - If SL34 = 3 or 4 then impairment = impairment + 1
35. tension headaches or digestive problems SEVERE (NOT MOD/SEV) - If SL35 = 4 then impairment = impairment + 1
36A. concerns or worries about your sleep mod/sev
36B. worried or distressed about sleep problems much/very much – If SL36a OR SL36b = 3 or 4 then impairment = impairment+1
41. sleep probs interfered with home management 7-10/0-10 - If SL41 ≥ 7 then impairment = impairment +1
42. sleep probs interfered with ability to work 7-10/0-10 - If SL42 ≥ 7 then impairment = impairment +1
43. sleep probs interfered with social life 7-10/0-10 - If SL43 ≥ 7 then impairment = impairment +1
44. sleep probs interfered with close relationships 7-10/0-10 - If SL44 ≥ 7 then impairment = impairment +1
We say that Criterion C is met if impairment ≥ 1
    • "Therefore, both the ISI and PSQI can be used for screening individuals with insomnia regardless of the underlying cause of insomnia (primary and secondary insomnia). Consistent with a comparative study [50] using the DSM-IV, ICD-10, and ICSD-II to evaluate insomnia symptoms in the American Insomnia Survey, our findings showed that studies employing the ICSD-II as the reference test had lower pooled sensitivity in the ISI and specificity in the PSQI compared with other reference tests. The inclusion of different diagnostic criteria of insomnia is likely to account for much of this matter. "
    [Show abstract] [Hide abstract] ABSTRACT: Background Insomnia is a highly prevalent health complaint in the modern societies; however, insomnia remains under-diagnosed and under-treated. Although screening tools, including the Insomnia Severity Index (ISI), Athens Insomnia Scale (AIS), and Pittsburg Sleep Quality Index (PSQI), are widely used for assessing the risk of insomnia, the diagnostic properties have yet to be summarized in a systematic manner. Objectives To estimate and to compare the diagnostic accuracy of the ISI, AIS, and PSQI for insomnia screening. Data sources We systematically searched EMBASE, PubMed, PsycINFO, CINAHL and Chinese Electronic Periodic Services for data from their inception to May 20, 2015. Data selection Original articles that had assessed the sensitivity and specificity of the ISI, AIS, or PSQI against a reference standard in adult participants (age > 18) were included. Results A total of 19 studies comprising 4693 participants were included. The pooled sensitivity for the ISI, AIS, and PSQI was 88% (95% confidence interval [CI] = 0.79 to 0.93), 91% (0.87 to 0.93), and 94% (0.86 to 0.98), respectively. The pooled specificity was 85% (0.68 to 0.94), 87% (0.68 to 0.95), and 76% (0.64 to 0.85); and the pooled DORs was 41.93 (8.77 to 200.33), 67.7 (23.4 to 196.1), and 53 (15.5 to 186.2), respectively. The summary estimates did not differ significantly among the ISI, AIS and PSQI (all P > 0.05). Conclusions The current evidence indicates that the ISI, AIS, and PSQI yield comparable diagnostic properties for insomnia screening.
    Article · Jun 2016
    • "Only employed respondents provided data on absenteeism, presenteeism, and overall work impairment but all respondents who reported at least one residual symptom rated their activity impairment. Information on sleep difficulties was assessed using the Brief Insomnia Questionnaire (BIQ [25] ). Information collected in the BIQ included in this analysis was the number of nights out of the past 7 with sleep problems due to trouble falling asleep, trouble staying asleep, trouble waking too early, waking feeling tired or unrested, and nights with at least one of these problems. "
    [Show abstract] [Hide abstract] ABSTRACT: Study Objective . To measure the association of symptoms attributed to residual effects of sleep medication (e.g., drowsiness, difficulty concentrating, and impaired memory) on self-reported functioning and satisfaction with these medications. Methods . Individuals using prescription medications for insomnia were invited to complete an Internet-based survey. Respondents were compared according to the presence of self-reported residual effects; relationships between severity of these effects and outcomes were modeled using regression. Measures included the Brief Insomnia Questionnaire, Work Productivity and Activity Impairment Questionnaire, and SATMED-Q. Subgroup analyses were conducted with patients aged ≥65 years. Approximately 80% reported experiencing ≥1 residual effect. The severity of residual effects was associated with increased residual effect-related work impairment, including absenteeism (RR = 1.46, p < 0.001 ), presenteeism (RR = 1.12, p < 0.001 ), overall work impairment (RR = 1.13, p < 0.001 ), and nonwork activity impairment (RR = 1.11, p < 0.001 ). More severe residual symptoms were also associated with increased difficulty in home management (Beta = .31, p < 0.001 ), ability to work (Beta = .31, p < 0.001 ), social relationships, (Beta = .32, p < 0.001 ), close personal relationships (Beta = .30, p < 0.001 ), and lower medication satisfaction (Beta = - . 37 , p < 0.001 ). Conclusions . Individuals using medications for insomnia commonly experience symptoms considered as residual effects, and these symptoms are associated with greater interference of sleep-related problems at work, at home, and with social relationships.
    Full-text · Article · Dec 2015
    • "The criterion validity and test– retest reliability of the Hong Kong version of the BIQ are satisfactory [15] . The study's senior authors (KC and WY) conducted clinical reappraisal interviews using a standardized semi-structured questionnaire, developed specifically for BIQ validation [14], blind to the subjects' BIQ results. The areas under the receiver operating characteristics curve for the DSM-IV-TR, DSM-5, ICD-10, and RDC/ ICSD-2 insomnia disorder ranged from 0.76 to 0.86, indicating a high individual-level concordance between the BIQ and clinical-interview diagnoses. "
    [Show abstract] [Hide abstract] ABSTRACT: To compare the prevalence of insomnia according to symptoms, quantitative criteria, and Diagnostic and Statistical Manual of Mental Disorders, 4th and 5th Edition (DSM-IV and DSM-5), International Classification of Diseases, 10th Revision (ICD-10), and International Classification of Sleep Disorders, 2nd Edition (ICSD-2), and to compare the prevalence of insomnia disorder between Hong Kong and the United States by adopting a similar methodology used by the America Insomnia Survey (AIS). Population-based epidemiological survey respondents (n = 2011) completed the Brief Insomnia Questionnaire (BIQ), a validated scale generating DSM-IV, DSM-5, ICD-10, and ICSD-2 insomnia disorder. The weighted prevalence of difficulty falling asleep, difficulty staying asleep, waking up too early, and non-restorative sleep that occurred ≥3 days per week was 14.0%, 28.3%, 32.1%, and 39.9%, respectively. When quantitative criteria were included, the prevalence dropped the most from 39.9% to 8.4% for non-restorative sleep, and the least from 14.0% to 12.9% for difficulty falling asleep. The weighted prevalence of DSM-IV, ICD-10, ICSD-2, and any of the three insomnia disorders was 22.1%, 4.7%, 15.1%, and 22.1%, respectively; for DSM-5 insomnia disorder, it was 10.8%. Compared with 22.1%, 3.9%, and 14.7% for DSM-IV, ICD-10, and ICSD-2 in the AIS, cross-cultural difference in the prevalence of insomnia disorder is less than what is expected. The prevalence is reduced by half from DSM-IV to DSM-5. ICD-10 insomnia disorder has the lowest prevalence, perhaps because excessive concern and preoccupation, one of its diagnostic criteria, is not always present in people with insomnia. Copyright © 2014 Elsevier B.V. All rights reserved.
    Article · Jan 2015
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