Brief Report: Telephone Administration of the Autism Diagnostic
Interview—Revised: Reliability and Suitability for Use
Jessica Ward-King•Ira L. Cohen•
Henderika Penning•Jeanette J. A. Holden
Published online: 2 March 2010
? Springer Science+Business Media, LLC 2010
one of the ‘‘gold standard’’ diagnostic tools for autism
spectrum disorders. It is traditionally administered face-
to-face. Cost and geographical concerns constrain the
employment of the ADI-R for large-scale research projects.
The telephone interview is a reasonable alternative, but has
not yet been examined for reliability with face-to-face
administration. In this study, participants were interviewed
both face-to-face and on the telephone using the complete
ADI-R interview. Results indicate that there was no sig-
nificant difference between the algorithm scores or the
diagnoses arrived at for face-to-face and telephone admin-
istrations. Reliability statistics across the two modalities
were very good and indicate that telephone interviews using
the ADI-R are a viable option for researchers.
The Autism Diagnostic Interview—Revised is
diagnostic interview—revised ? Telephone interview ?
Autism spectrum disorders ? Autism
The Autism Diagnostic Interview (ADI; Le Couteur et al.
1989) was originally intended for research, as an aid to
diagnosing autism according to the ICD-10 (World Health
Organization 1993) and DSM-IV (American Psychiatric
Association 1994) definitions. This original version of the
standardized, investigator-based interview was intended
for caregivers of subjects with a chronological age of
5 years or older, and a mental age of at least 2 years. The
interview is semi-structured, contributing to both its reli-
ability and validity. It is based upon open-ended questions
that inquire about various aspects of a subject’s devel-
opment and current behaviour, allowing the informant to
describe freely the relevant traits of the affected individ-
ual. The interviewer uses clearly defined codes to classify
the traits and behaviours described in response to each
The ADI-R fills a need in research for a sensitive and
reliable tool based on accepted diagnostic criteria that can
determine whether an individual fits into the diagnostic
category of ‘‘autism’’ and has become a ‘‘gold standard’’
diagnostic tool for autism research. In the absence of a
reliable tool, it is difficult for researchers to ensure con-
sistent classification of individuals as having autism or
Since its creation in 1989, the ADI (and then the ADI-R)
has been employed as a face-to-face semi-structured inter-
view. For clinical use, this makes sense; the ADI-R is often
used as part of a wider, multidisciplinary assessment in the
J. Ward-King ? H. Penning ? J. J. A. Holden
Department of Psychiatry, Queen’s University, Kingston,
ON K7M 8A6, Canada
J. J. A. Holden
Department of Physiology, Queen’s University, Kingston,
ON K7M 8A6, Canada
J. J. A. Holden (&)
Genetics and Genomics Research Laboratory, Ongwanada,
Kingston, ON K7M 8A6, Canada
e-mail: email@example.com; firstname.lastname@example.org
I. L. Cohen
Department of Psychology, NYS Institute for Basic Research in
Developmental Disabilities, Staten Island, NY 10314, USA
J. Ward-King ? I. L. Cohen ? H. Penning ? J. J. A. Holden
Autism Spectrum Disorders, Canadian-American Research
Consortium (ASD-CARC), www.AutismResearch.ca
J Autism Dev Disord (2010) 40:1285–1290
diagnosis of autism, with families being seen in a clinic. For
research purposes, the ADI-R is often used for diagnostic
confirmation to empirically assess the previous clinical
diagnosis that an individual has autism. It is not always
feasible for a participating family to come to the research
centre to see the interviewer or for an interviewer to travel
to each family’s home. Further, the use of the ADI-R for
research requires that the interviewer obtain extensive
training and must become reliable in scoring the interview
with a designated research group (Le Couteur et al. 2009). It
is difficult and expensive to train sufficient interviewers to
send to each family’s home, especially for large-scale
studies that sample from a wide geographic area. In short,
while the ADI-R has long been used successfully as a
face-to-face interviewing tool, it has become necessary to
adapt this reliable and valid diagnostic tool for the needs of
large-scale research projects such as those designed to
identify genetic and environmental factors leading to ASD
One group (Vrancic et al. 2002) adapted the ADI-R for
administration over the telephone. In that study, the
authors used the algorithm items of the ADI-R to develop
an interview that consisted of 47 items and required
approximately 20–40 min to complete. The wording of
the interview was completely rephrased with necessary
inclusion of examples and explanations to obtain reliable
answers over the telephone. As it is not the complete
ADI-R, the Autism Diagnostic Interview—Telephone
Screening in Spanish (ADI-TSS) was developed as a
screening tool that enables the selection of cases of
probable autism. It was designed to compliment, and not
replace, the ADI-R; the authors suggested that patients
who are identified by the ADI-TSS should later be
assessed using the ADI-R.
The ADI-R takes approximately 2 h to complete.
Partly for this reason, the full interview has never been
tested using the telephone modality. While the ADI-R can
take several hours to complete, its authors report that
informants find it an enlightening and comfortable expe-
rience ‘‘because they are allowed to describe important
aspects of their child’s behaviour in their own words’’
(Lord et al. 1994, p. 663). It is clear that it would be an
advantage to autism spectrum disorder (ASD) research if
the ADI-R could be administered in one session over the
telephone, as it could then be used inexpensively and
efficiently with minimum disruption for both the inter-
viewers and participants. In this study we sought to
determine whether it is possible for participants to com-
plete the ADI-R with a trained ADI-R interviewer, and
whether and how the telephone interview results would
compare with face-to-face interview results in terms of
Twenty children with autism and their primary caregivers
were recruited for this study. Children’s ages at the time of
the first interview ranged from 3.42 to 19.0 years (mean:
8.92 years). There were 14 boys and six girls included in the
study, all of whom had a previous clinical diagnosis of an
ASD; 15 with a diagnosis of Autistic Disorder; four with a
diagnosis of Asperger’s Disorder; and one with a diagnosis
of PDD Not Otherwise Specified. No IQ or adaptive func-
tioning data was available for the participants. One primary
caregiver of each child (16 mothers, 4 fathers) volunteered
to act as the informant on both face-to-face and telephone
administrations of the ADI-R. All participants were
recruited by the Autism Spectrum Disorders—Canadian
and American Research Consortium (ASD-CARC) through
an on-line Research Registry (www.AutismResearch.ca),
which invites families to complete questionnaires online
and to agree to be contacted when studies are being carried
out in their area. For this study, participants were recruited
from a circumscribed geographical area in Southeastern
Ontario. All informants identified themselves as Caucasian.
Informants were asked to participate in an interview using
the Autism Diagnostic Interview—Revised (ADI-R; Lord
et al. 1994) twice: once face-to-face with the interviewer,
and once in an interviewer-initiated telephone call at a
mutually convenient time. A single interviewer conducted
all interviews. The order in which the interviews were
conducted was counter-balanced. Interviews were com-
pleted at least 14 and not more than 122 days apart, with
a mean interval of 29.6 days (standard deviation =
30.97 days), and all were completed within a 6-month
The interview was the complete, standard ADI-R
interview (Lord et al. 1994) which includes items relating
to both verbal and non-verbal individuals. The ADI-R was
scored using the algorithm provided, but only at the con-
clusion of data collection, after all interviews had taken
place. The interviewer (H.P.) was fully trained and certified
in conducting and scoring the ADI-R for research purposes.
The ADI-R is scored using an algorithm that examines
the main diagnostic criteria emphasized by the DSM-IV
and ICD-10. There are four domains examined by the ADI-
R. Domain A assesses qualitative abnormalities in reci-
procal social interaction (QARSI), specifically examining
use of eye-gaze and facial expression, development of peer
relationships and emotional reciprocity, and seeking to
1286J Autism Dev Disord (2010) 40:1285–1290
share one’s own enjoyment. Domain B assesses qualitative
abnormalities in communication (QAC), and arrives at
different scores for participants who are verbal (BV), and
those who are non-verbal (BNV). For the present study, BV
and BNV scores were analyzed together as one commu-
nication score since there were only four non-verbal par-
ticipants and our concern was with repeat test reliability.
Domain C assesses restricted, repetitive and stereotyped
patterns of behaviour (RRSPB), including compulsions and
unusual preoccupations as well as stereotyped mannerisms.
Domain D deals with the requirement that abnormalities in
the three diagnostic behavioural criteria be apparent before
age 36 months.
Domain means for the first three content domains were
compared using repeated measures multivariate analysis of
variance (MANOVA). Both domain and method of inter-
view served as within-subjects factors. Order of the inter-
view format (face to face or telephone) served as a
between-subjects factor. Domain D scores at both inter-
views were negatively skewed (-1.5 and -1.2) and so
these domain scores were compared across time with the
Wilcoxon matched pairs test, and across group with the
Mann–Whitney U, both non-parametric tests. Domain
scores across interview conditions did not significantly
vary with prior diagnosis (all p values[0.17) and groups
did not significantly differ in mean age (F(1,18) = 0.7, ns).
Figure 1 shows the mean (±SEM) domain scores across
interview conditions for the two groups. While those who
received the telephone interview first had marginally lower
group means on the first and second interviews, these dif-
ferences were not statistically significant. Overall, there
were no significant main effects for group (F(1,18) = 1.07,
ns), method of interview (F(1,18) = 0.07, ns), or their
interaction (F(1,18) = 0.002, ns). Multivariate tests also
revealed no significant effects due to interaction of domain
with group, domain by interview type, or their three-way
interaction (all p values[0.6). Likewise, Domain D scores
did not significantly vary across time or group (all p values
[0.6). Table 1 shows the ADI-R means and standard
deviations across interview conditions for the two groups.
Telephone interview domain scores were correlated
(Pearson R) with face-to-face interview scores as the ref-
erence in order to examine repeat reliability. Correlations
across domains A, B, C, and D were, respectively, 0.84,
0.73, 0.90, and 0.89; all p values\0.001. Mean (SD) ADI-
R difference scores across subjects within conditions and
interview conditions are shown in Table 2. As shown,
ADI-R DOMAIN MEANS ACROSS INTERVIEW TYPE AND ORDER
MEANS (+/- 95% CI)
Fig. 1 ADI-R domain means (±95% confidence interval) across interview type and order. QARSI qualitative abnormalities in reciprocal social
interaction, QAC qualitative abnormalities in communication, RRSPB restricted, repetitive and stereotyped patterns of behaviour
J Autism Dev Disord (2010) 40:1285–12901287
difference scores did not significantly vary across groups
and were close to zero (F(2,36) = 0.5, ns).
In terms of diagnostic agreement, 18 of the 20 cases met
ADI-R criteria for autism based on the face-to-face inter-
view. The other two cases met two of the three content
domain criteria suggesting they could be classified as
PDDNOS (Rutter et al. 2003). Of the 18 autism cases, 15
(83%) met criteria for autism using the telephone interview
and the other 3 would have been classified as PDDNOS. Of
the two cases classified as PDDNOS based on the face-to-
face interview, one met criteria for autism and the other for
PDDNOS using the telephone interview. Thus, irrespective
of method, all cases remained in the autism spectrum. We
did not compute Kappa for a measure of agreement
because we did not have a non-spectrum comparison
group; autism and PDDNOS groups are typically difficult
to distinguish (Mahoney et al. 1998), and the number of
PDDNOS cases was too small to provide a meaningful
Our results indicate that the ADI-R remains a reliable
diagnostic interview when it is administered over the
telephone. There were no differences in the results, either
on the diagnostic algorithm, or in terms of diagnosis
reached depending on interview administration method.
The telephone has many advantages as an interview
modality in research settings. For one, it is cost-effective
(Bauman 1993; Burnard 1994; Corey and Freeman
1990; Marcus and Crane 1986; Musselwhite et al. 2007;
Siemiatycki 1979; Tausig and Freeman 1988; Wilson et al.
1998); Marcus and Crane (1986) argue that telephone
interviewing techniques could reduce costs 50–75% when
compared to face-to-face interviews. Use of the telephone
to conduct interviews allows an interviewer to cover a
larger geographical area (Burnard 1994; Musselwhite et al.
2007). Telephone interviews can be scheduled and com-
pleted more quickly than can face-to-face interviews
(Worth and Tierney 1993).
There is scientific support for the telephone interview as
a legitimate method of data collection (Oppenheim 1992;
Barriball et al. 1996; Law 1997). Like face-to-face inter-
views, telephone interviews have a high response rate
(Polit and Hungler 1991) and incorporate the possibility for
the interviewer to clear up misunderstandings (Robson
1993). Robson (1993) also argues that they have smaller
interviewer effects and a lower tendency for the respondent
to give socially desirable responses. Quality control, which
can be ensured with fewer, centrally-located interviewers
who have the opportunity to self-correct, is a feature of
telephone interviewing (Lavrakas 1987). The interviewers
are also able to take interview notes more discreetly over
the telephone, minimizing the discomfort that participants
may have during the interview (Musselwhite et al. 2007).
Telephone interviews are not without disadvantages.
Establishing rapport can be a problem in telephone inter-
views (Robson 1993). It is important to establish an
appropriate relationship in order for the telephone interview
to be successful, and for authentic responses to be provided.
Furthermore, it has been argued that telephone interviews
produce shorter responses than face-to-face interviews
(Marcus and Crane 1986), possibly because they are more
focused than face-to-face interviews (Carr and Worth
2001). The possible length of an interview changes with the
modality, however. Many researchers advise a shorter
telephone interview as compared to face-to-face interviews,
with Lavrakas (1987) suggesting 20–30 min as a maximum.
However, Waterman et al. (1999) found that telephone
interviews of up to 60 min were ‘‘efficient in time and
conducive to free-flowing conversation’’. There is nothing
preventing a telephone call from lasting for even longer
than this, though fatigue may set in. It is important to note
that for this study all interviews were conducted comfort-
ably in one session, regardless of modality. Participants
reported that they preferred the telephone interview due to
its convenience and the length of the interview did not cause
significant concern. Thus telephone interviews have dif-
ferent characteristics compared to face-to-face interviews,
Table 1 Mean (SD) domain scores across group and method of interview for each ADI-R domain
Overall 20 21.75 (4.78)16.80 (4.72)5.85 (3.00) 21.70 (4.86)16.85 (5.15)5.50 (3.36)
Face first 1022.20 (4.37)17.90 (3.11) 6.60 (3.37)22.60 (3.66)17.60 (5.04)6.10 (4.46)
Phone first1021.30 (5.36)15.70 (5.89)5.10 (2.51)20.80 (5.88) 16.10 (5.43)4.90 (1.80)
Table 2 Mean (SD) difference scores across subjects within groups
and method of interview for each ADI-R domain
Overall 200.05 (2.72)-0.05 (3.66)0.35 (1.50)
Face to face 10-0.40 (3.03)0.30 (4.16) 0.50 (1.58)
Telephone100.50 (2.46)-0.40 (3.27)0.20 (1.48)
1288J Autism Dev Disord (2010) 40:1285–1290
but are largely proven to yield comparable results
(Siemiatycki 1979). These results are consistent with the
findings of this study.
As with any interview or rating scale that is applied
twice within a reasonably tight timeline by the same
interviewer, the issue of order effect is a significant one;
however, in this study we found none. This may be because
a single interviewer performed all of the face-to-face and
telephone interviews. This method was chosen to reduce
inter-rater biases that may obscure the data. However, this
resulted in a lack of blindness of the interviewer to the
participant’s diagnosis. The first interview was always
performed blind, but while the second interview was per-
formed on average a month later, the interviewer was
potentially able to recall the diagnosis reached as a result of
the first interview. While the interviewer could be expected
to forget many of the details of each case over the month or
more between interviews, overall impressions and biases
are difficult to erase in that time. For example it is possible
that the interview that is done second might benefit from
the knowledge gained in the first interview. In an effort to
reduce these order effects, the interviewer did not compute
the algorithm scores for any of the interviews until all
interviews had been completed. This minimized the
amount of information the interviewer had about the indi-
vidual’s diagnosis prior to any one interview. Furthermore,
the interviewer had a full schedule of other ADI-R inter-
views to complete during that time period and reports that
it was difficult to recall and predict responses to items on
the ADI-R. While these exigencies may have contributed to
better data collection, it is still possible that some bias may
have clouded the second interviews. This is why it is sig-
nificant that counterbalancing of interview modality was
practiced, and that no order effects were found in the data.
This study focused on establishing the reliability of the
ADI-R by telephone interview for use in research. Future
studies should consider inclusion of a control sample of
individuals without autism in order to examine the diag-
nostic specificity of the telephone ADI-R. For research
purposes, the ADI-R is often used as a confirmatory diag-
nostic tool with individuals who have already received, or
are strongly suspected of having, an ASD diagnosis. It will
be useful to examine whether the ADI-R telephone inter-
view can be reliably and validly used to exclude the ASD
diagnosis in research participants for control purposes.
The results presented here indicate that when the ADI-R
is used to confirm an existing diagnosis for the purpose of
research, the telephone modality is as good as the tradi-
tional face to face administration. However, it should be
noted that when used for individual scores or when pre-
vious diagnoses are not clear, the administration of the
ADI-R over the telephone is not indicated. Telephone ADI-
R administration is not a substitute for face to face clinical
judgment and these data do not indicate its use for indi-
vidual assessment or diagnosis on a clinical basis.
This study indicates that, for research purposes, adminis-
tration of the ADI-R as a confirmatory diagnostic tool can
be carried out by trained interviewers over the telephone in
place of the traditional face-to-face interview. Given the
substantial advantages of the use of telephone over face-to-
face interviews, this finding is significant and overdue.
research subjects and their extended family members for their
enthusiastic support of this study. This work was supported by an
OMHF grant (JJAH, principal investigator) and a CIHR Interdisci-
plinary Health Research Team grant (RT-43820) to the Autism
Spectrum Disorders Canadian-American Research Consortium (ASD-
CARC: www.autismresearch.ca) (JJAH, principal investigator).
JW-K is a postdoctoral trainee with the CIHR/Autism Speaks Autism
SPectrum Interdisciplinary REsearch (ASPIRE) Strategic Training in
Health Research Program (PI: JJAH) (www.AutismTraining.ca).
We extend our sincere appreciation to our
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