Measures of Pediatric Function
Child Health Assessment Questionnaire (C-HAQ), Juvenile Arthritis Functional
Assessment Scale (JAFAS), Pediatric Outcomes Data Collection Instrument (PODCI),
and Activities Scale for Kids (ASK)
SUSAN E. KLEPPER
Children with a rheumatic disease frequently experience
impairments in one or more body systems; these may
include pain, stiffness, fatigue, muscle weakness, soft tis-
sue contractures, and poor exercise capacity. These im-
pairments may directly limit the child’s ability to perform
some physical activities or may do so indirectly if the
child or parent fears such activities may cause injury or a
disease flare. It is essential to understand the impact of
rheumatic disease on a child’s activities in order to guide
intervention and monitor changes in functional abilities
over time and with targeted therapies. This is especially
important when disease onset occurs at a very young age
because the long-term effects of physical limitations can
negatively impact the child’s quality of life.
The best measure of activities for a particular child or
group of children depends on the context of the evalua-
tion, including the physical and social environment. For
example, a child may perform a task like standing up from
the floor without assistance in a quiet, standardized envi-
ronment like the clinic, but does not perform the same task
during physical education class at school or after a fall in
the community. Holsbeeke et al (1) suggest there are 3
related but separate constructs of physical activity that are
distinguished by this person-environment interaction. Ca-
pacity describes what a person can do in a standardized
controlled environment, capability describes what a per-
son can do in his/her daily environment, and performance
describes what a person actually does in his/her daily
Four measures of physical activities that have been de-
veloped for or are appropriate for use in children with a
rheumatic disease will be reviewed. Only the Juvenile
Arthritis Functional Assessment Scale (JAFAS) and the
Childhood Health Assessment questionnaire (C-HAQ)
were developed specifically for children with juvenile ar-
thritis. The C-HAQ, the most frequently used measure of
activities in pediatric rheumatology, evaluates a child’s
capability to perform activities in their daily environment,
while the JAFAS measures the child’s capacity in the daily
environment. Both the Activities Scale for Kids (ASK) and
the Pediatric Outcomes Data Collection Instruments
(PODCI), although not specifically designed for use in
pediatric rheumatic diseases, assess physical function in
children with chronic health disorders, including child-
hood arthritis. The ASK includes 2 versions, one that
measures a child’s physical capability in his/her daily
environment (ASKc) and one that measures the child’s
performance of the same activities in their daily environ-
ment (ASKp). The ASK is also the only measure that re-
quires the child to be the respondent because, as Young
et al (2) state, “it is the child who is most familiar with
his or her own abilities or limitations in each setting.”
Finally, the PODCI, the most comprehensive of the 4 in-
struments, measures capability primarily, and includes a
pediatric version to be completed by a parent and an
adolescent version that can be completed by the parent,
child, or both. Each of these 4 measures includes activities
that are necessary and important to children across a wide
age range. The use of 2 or more of these measures in
combination may provide clinicians with the best under-
standing of a child’s typical activities and participation in
CHILDHOOD HEALTH ASSESSMENT
Purpose. To assess health status and physical func-
tion in children with juvenile arthritis. The populations
are children, ages 1–19 years with juvenile arthritis (3).
It is also validated for use in children with juvenile der-
Susan E. Klepper, PhD, PT: Columbia University, New
York, New York.
Dr. Klepper has received honoraria (less than $10,000)
from The Association of Rheumatology Health Profession-
Address correspondence to Susan E. Klepper, PhD, PT,
Assistant Professor of Clinical Physical Therapy, Columbia
University, 710 West 168th St., 8th Floor, New York, NY
10032. E-mail: email@example.com.
Submitted for publication January 31, 2011; accepted in
revised form May 9, 2011.
Arthritis Care & Research
Vol. 63, No. S11, November 2011, pp S371–S382
© 2011, American College of Rheumatology
MEASURES OF FUNCTION
matomyositis (4,5) and systemic lupus erythematosus (6),
and used for children with chronic musculoskeletal pain
syndromes (7), and spina bifida (8). The original pub-
lication was by Singh et al in 1994 (3). Lam et al (9)
proposed several revised versions that included 8 addi-
tional items to assess the child’s functional strengths as
well as deficits.
Content. Includes the International Classification of
Functioning, Disability, and Health components of body
function (sensation of pain) and activities and partici-
pation (basic and instrumental activities of daily living
[ADLs] considered to be important, and often difficult for
children with arthritis), as well as a measure of overall
health status. Revised versions contain 8 additional more
physically challenging activities.
Number of items. The disability index (DI) in the orig-
inal C-HAQ includes 30 items grouped into 8 domains
of physical function, dressing and grooming (4 items),
arising (2 items), eating (3 items), walking (2 items), hy-
giene (5 items), reach (4 items), grip (5 items), and ac-
tivities (5 items). The DI in revised versions (C-HAQ38)
includes 8 additional, more physically-challenging items
(9). The discomfort index (pain) and health status index
(overall health status) each include a single item, a 15-cm
visual analog scale (VAS).
Response options/scale. The original C-HAQ DI is
scored on a 4-point categorical scale that indicates how
much difficulty a child has had performing each task dur-
ing the past week (0 ? without any difficulty, 1 ? with
some difficulty, 2 ? with much difficulty, and 3 ? unable
to do). The respondent marks not applicable if the task is
beyond the child’s developmental age, and the respondent
indicates if aids/devices or assistance were needed for any
Several revised versions ask respondents to compare the
child’s capabilities to other children the same age. The
VASC-HAQ38(9) uses a 10-cm VAS anchored at the left end
with the phrase “Much worse than most other kids my
age” and at the right end with “Much better than other kids
my age.” The CATC-HAQ38(9) and C-HAQ38CATII (10)
have 5 response options: ?2 ? much worse, ?1 ? a little
worse, 0 ? the same, 1 ? a little better, 2 ? much better
compared to most kids my age. The C-HAQ38CATI (10)
uses the original 0–3 response scale. The ChoiceC-HAQ38
(9) includes 2 sentence stems for each question, stating
1) the activity was performed by some children “really
easily,” or 2) but other children weren’t able to perform the
activity or were only able to do so “slowly or with diffi-
culty.” The respondent chooses one sentence stem and
then indicates if the chosen statement was “really true” or
“sort of true” for the child.
Recall period for items. 1 week.
Endorsements. The original C-HAQ is the preferred
measure of physical function in the Paediatric Rheumatol-
ogy International Trials Organisation core set of outcome
measures for pediatric rheumatology (11).
Examples of use. Oliveira S, Ravalli A, Pistorio A, Cas-
tell E, Malattia C, Prieur AM, et al. Proxy-reported health-
related quality of life of patients with juvenile idiopathic
arthritis: the Pediatric Rheumatology International Trials
Organization multinational quality of life cohort study.
Arthritis Rheum 2007;57:35–43.
Singh-Grewal D, Schneiderman-Walker J, Wright V,
Bar-Or O, Beyene J, Selvadurai H, et al. The effects of
vigorous exercise training on physical function in children
with arthritis: a randomized, controlled, single-blinded
trail. Arthritis Rheum 2007;57:1202–10.
Van Brussel M, Lelieveld OT, van der Net J, Engelbert
RH, Helders PJ, Takken T. Aerobic and anaerobic exer-
cise capacity in children with juvenile idiopathic arthritis.
Arthritis Rheum 2007;57:891–7.
Lelieveld OT, Armbrust W, van Leeuwen MA, Duppen
N, Geertzen JH, Sauer PJ, et al. Physical activity in adoles-
cents with juvenile idiopathic arthritis. Arthritis Rheum
How to obtain. The original C-HAQ can be found on
the American College of Rheumatology (ACR) web site at
assessments/chaq.pdf#search?%22CHAQ%22. Revised ver-
sions of the C-HAQ are available through the authors
(9,10). There is no cost.
Method of administration. By interview or self-report of
children age ?8 years. Parent reports as proxy for a child
age ?8 years.
Scoring. All versions are scored by hand. The original
C-HAQ and revised versions provide instructions on scor-
ing to the respondent. No instructions for handling miss-
ing values are provided.
Score interpretation. Part I (DI). In the original C-HAQ,
scoring range is 0–3, higher scores reflect greater disabil-
ity. The highest scoring item in each category determines
the score for that category. If the respondent indicates the
need for assistance or the use of aids/devices to perform a
task, the minimum score for that category is 2. The mean
score for the 8 domains makes up the DI (range 0–3).
In most revised versions of the C-HAQ, the summary
score for the DI is determined by averaging the scores on
all answered items (30 or 38), eliminating the domain
structure, and the use of aids/devices and assistance.
In the VASC-HAQ38,each item is scored as the distance
from the left end of the 10-cm line to the point where the
child/parent places a slash mark to indicate the child’s
ability compared to other children of that age. The DI is the
mean score for all 38 items. Higher scores indicate better
function or less disability.
The CATC-HAQ38uses a 5-point scale ranging from ?2
(much worse) to 2 (much better) than other children of the
same age. Higher positive scores indicate better function or
The C-HAQ38CATI uses the original C-HAQ 0–3 score
range; the DI is calculated as the mean of all 38 items, with
higher scores indicating greater disability.
The ChoiceC-HAQ38uses a 0–4 scale, with higher scores
indicating better function or less disability.
Part II (discomfort index) and Part III (health status).
Each are measured on separate 15-cm VAS. The distance
from the left end of the scale to the respondent’s mark is
measured and multiplied by 0.2 to calculate the score
(range 0–3). Both the discomfort index and health status
can be rescaled to 0–100 scales. Higher scores indicate
greater pain and worse overall health status.
Normative values are not available for this criterion-
referenced test. Dempster et al (12) reported mean scores
on the DI of the original C-HAQ that represent no dis-
ability (0), mild disability (0.24), mild-to-moderate disabil-
ity (0.71), and moderate disability (1.53).
Respondent burden. The original C-HAQ takes 10 min-
utes for the respondent to complete, the C-HAQ38version
takes 10–15 minutes to complete.
Adminstrative burden. The original version takes ?10
minutes when administered by interview; slightly longer
The time to score varies by version of the C-HAQ. The
original C-HAQ and C-HAQ38CATI take less than 2 min-
utes to score the DI; additional time is necessary to mea-
sure the VAS for pain and health status. The VASC-HAQ38
takes ?15–20 minutes to measure all 38 VAS for the DI
plus scales for pain and health status. No special training
is needed to score or interpret, although it is necessary to
read the original publications describing the scoring for
each version of the C-HAQ.
Translations/adaptations. The original C-HAQ has been
translated and validated for use in over 40 languages and
cultures including Spanish, Portuguese, Italian, Dutch,
Swedish, and Norwegian. Several revised versions of the
C-HAQ38have been translated into Dutch, Swedish, Turk-
ish, Greek, and Danish.
Method of development. The original C-HAQ (3) con-
sists of items from the Stanford Health Assessment Ques-
tionnaire (HAQ), adapted for use in children ages 1–19
years; several new questions were added to each func-
tional area so there was at least 1 question that was rele-
vant to children of all ages.
The disability section assesses functions in 8 areas or
subscales that describe mostly typical ADLs, although
individual item and section scores are not reported. In the
C-HAQ38versions, additional items were derived from
investigators’ own experience and interviews of patients
with musculoskeletal conditions. The purpose was to
measure strengths as well as weaknesses by comparing the
child’s abilities to most other children of the same age
Acceptability. Authors do not report the reading level,
however the language for most items is simple and easy to
read and understand. Missing data do not appear to be a
problem and have not been addressed by the authors. The
original C-HAQ is known to have a ceiling effect in chil-
dren with mild disease, making it difficult to measure
improvement at the better end of the functional spectrum.
Reliability. Original C-HAQ (1). Internal consistency
(Cronbach’s coefficient ?) was 0.94. Test–retest stability
was established for parents’ responses on the DI adminis-
tered once in the clinic and completed by parents at home
within a mean interval of 12.8 days, with an SEM of 2.1.
Paired t-test showed no significant difference between the
2 test scores (P ? 0.9), and a Spearman’s correlation coef-
ficient of 0.79 (P ? 0.002) showed strong test–retest reli-
ability. Concordance between parent and child responses
on the DI was Spearman’s rho ? 0.84, P ? 0.001.
C-HAQ38version (9). Concordance between parent and
child responses on the DI showed the intraclass correla-
tion coefficient (ICC) values ranging from 0.41–0.68.
Validity. Original C-HAQ (3). Content was evaluated
by a panel of experts (rheumatologists, nurses, social
workers, physical and occupational therapists).
Criterion validity measures: parents’ responses on the
DI demonstrated strong positive correlations (P ? 0.0001
by Kendall’s tau) with accepted measures of disease activ-
ity, including the Steinbrocker Functional class (0.77),
number of involved joints (0.67), physician assessment of
global disease (0.67), and morning stiffness (0.54).
Discriminant validity measures: control group of 22
healthy children scored 0 on both the disability and dis-
comfort indices, indicating the ability of the C-HAQ to
discriminate between children with and without juvenile
C-HAQ38versions (9,10,13–15). Versions that included
8 more challenging items, removal of aids/devices and
assistance, and elimination of the domain structure re-
sulted in more normally-distributed data and better
ability to discriminate between patients and controls com-
pared to versions with 30 items. Relative efficiency of the
revised versions ranged from 1.01 (C-HAQ38CATI) to 2.32
Ability to detect change. Juvenile arthritis. Singh et al
(3) reported parent responses on the DI correlated signifi-
cantly with their global assessment of the child’s func-
tional status. The C-HAQ DI was more sensitive to change
than morning stiffness or active joint count.
Dempster et al (12) did not report the ability to detect
change in the original C-HAQ but provided guidelines for
interpreting the clinical utility of baseline and change
scores on the DI. They reported the mean score on the DI
that represents no disability (0), mild disability (0.24),
mild-to-moderate disability (0.71), and moderate disability
(1.53). The minimum important change (MIC) scores var-
ied by disability category. The MIC for improvement was
?0 (no disability), ?0.13 (mild), ?0.38 (mild-to-moder-
ate), and ?0.57 (moderate). The MIC for deterioration was
0.75 (no disability and mild disability), 0.63 (mild-to-mod-
erate disability), and 0.38 (moderate disability).
Juvenile dermatomyositis (juvenile DM). Huber et al (4)
reported adequate responsiveness of the C-HAQ by com-
paring changes in the DI and physician global assessment
(10-cm VAS) in 90 children with juvenile DM. Effect size
for 18 subjects who met the criterion for improvement
(3 cm on the VAS) was 1.05, with a standardized response
mean (SRM) of 1.20. In 72 subjects who did not meet the
criterion for improvement, effect size was 0.20 and SRM
Feldman et al (5) reported moderate to good responsive-
ness of the C-HAQ DI to clinical change in children with
juvenile DM undergoing specific drug therapies. Respon-
siveness of revised versions for use in juvenile DM has not
Pediatric Function S373
Critical Appraisal of Overall Value to the
Strengths. The C-HAQ is the most frequently used mea-
sure of physical function in pediatric rheumatology; the
instrument measures typical ADLs expected of children
ages 1–19 years that may be difficult for some children
with arthritis or other chronic musculoskeletal conditions.
It is included in the core set of outcome measures for
clinical trials in JIA, juvenile DM, and systemic lupus
The C-HAQ is simple to administer as a self-report for
children age ?8 years or by parents as proxy for their
child. It takes minimal time to administer and score.
Groups or conditions for which the instrument may be
appropriate include children with JIA, juvenile DM, SLE,
and chronic musculoskeletal pain syndromes.
Revised versions with 8 more challenging items (C-
HAQ38), modified response options, elimination of aids/
devices and assistance, and a simple mean score for all 38
items appear to result in a more normal score distribution,
improved ability to discriminate between patients and
healthy children, and greater sensitivity to change with
Caveats and cautions. The original C-HAQ suffers from
a ceiling effect in children with mild disease who have few
limitations in basic and instrumental ADLs, limiting its
ability to demonstrate improved physical function at the
higher end of the scale. The revised versions demonstrate
improved psychometric attributes and may prove over
time to be a better measure of physical function in children
with rheumatic disease.
Clinical usability. The original C-HAQ30is useful in
identifying activity limitations and change in physical
function over time or with intervention in children with
moderate to severe disease, but less so in children with
mild disease. The C-HAQ is easy to administer and score
and useful in both clinical and research settings. The re-
spondent burden is minimal.
Research usability. The original and revised versions of
the C-HAQ are easy to administer and score, however the
strong ceiling effect of the original C-HAQ may limit its
ability to detect change in physical function in children
with mild disease. The C-HAQ38CATI closely adheres to
the original C-HAQ and may be the most time-efficient for
research purposes. However the VASC-HAQ38,in which the
respondent compares the child’s abilities with those of
others the same age, may be more meaningful to the child
and provide a better measure of the child’s participation in
age-appropriate activities. Dempster et al (12) provide cut
points to judge a child’s level of disability and to detect
clinically important change at each level of disability.
JUVENILE ARTHRITIS FUNCTIONAL
ASSESSMENT SCALE (JAFAS)
Purpose. To measure functional ability in children with
rheumatic disease, ages 7–16 years by observing the
child’s actual performance of typical activities under stan-
dardized conditions and procedures. It was originally pub-
lished in 1989 by Lovell et al (16) as a companion measure
to the Juvenile Arthritis Functional Assessment Report, a
questionnaire-based measure of the child’s ability to per-
form activities during the previous week. There have been
no revisions or modifications to the original instrument.
Content. Activities of daily living (ADLs) considered by
expert opinion to be important and often difficult for chil-
dren with arthritis include dressing, cutting food, getting
in and out of bed, picking up an object from the floor while
standing, moving from standing to the floor and returning
to standing, walking 50 feet unaided, and walking up a
flight of 5 steps.
Number of items. 10 items in a single scale.
Response options/scale. Categorical (0–2) scale, based
on the time in seconds the child takes to complete each
task. The child’s performance is compared to a criterion
time (mean plus 2 SDs) established for healthy children
(0 ? task performed in less than or equal to the criterion
time; 1 ? task performed in time in excess of the criterion
time; 2 ? child unable to perform the activity).
Recall period for items. Performance-based measure
Endorsements. Developed for use in a US Bureau of
Maternal and Child Health and Resources Development
Examples of use. Bekkering WP, ten Cate RT, van Sui-
jlekom-Smit LW, Mul D, van der Velde EA, van den Ende
CH. The relationship between impairments in joint func-
tions and disabilities in independent function in children
with systemic juvenile idiopathic arthritis. J Rheumatol
Sircar D, Ghosh B, Ghosh A, Hildar S. Juvenile idio-
pathic arthritis. Indian Pediatr 2006;43:429–33.
How to obtain. The JAFAS, standardized testing proce-
dures, and detailed descriptions of the required equip-
ment, performance criteria, and guidelines for timing are
available from the original authors (16).
Method of administration. A trained tester observes the
child’s performance of each task and enters either the time
(seconds) needed to complete the task or “unable to com-
plete.” Standardized testing procedures and detailed de-
scriptions of required equipment and guidelines for testing
are available from the authors (16).
Scoring. The JAFAS is scored by hand. Specific scoring
instructions are found in the original paper and are avail-
able from the authors (16). The score range for each item is
0–2, and 0–20 for the entire scale (10 items). The authors
do not provide instructions for handling missing values,
however the scoring criteria include a score for the child
being unable to complete the task.
Score interpretation. Higher scores on individual items
(range 0–2) and on the full scale (range 0–20) indicate
greater activity limitation. The JAFAS is a criterion-refer-
enced measure, with the criterion (mean plus 2 SDs) being
the time required by healthy children to perform each task.
Respondent burden. Approximately 10 minutes.
Adminstrative burden. Approximately 15 minutes; train-
ing to administer the test is required but is minimal.
Translations/adaptations. The original version is in
English. The measure has not been adapted for other lan-
guages or cultures. Although the JAFAS was originally
developed for children with juvenile rheumatoid arthritis
(JRA), it is useful for children with other types of arthritis
or other childhood rheumatic diseases that negatively im-
pact a child’s ability to perform basic ADLs.
Method of development. Items were selected from
other assessment tools, including the Arthritis Impact
Measurement Scale, Health Assessment Questionnaire,
and the McMaster Health Index Questionnaire. Selected
items were reviewed by a panel of pediatric occupational
and physical therapists who had experience with patients
with JRA; the panel chose a variety of tasks that required
the use of all joints and muscle groups, were simple to test,
objectively measureable, and important to daily function.
The original scale of 23 items was reduced to include 10
tasks after all subjects were tested and data analysis per-
Acceptability. The scale, directions, and scoring re-
quirement are clearly written and understandable. Al-
though not discussed by the authors, missing data do not
appear to be a problem. There does appear to be a floor
effect whereby children with mild disease and few limita-
tions score very low on the scale and have little room to
show improvement in their physical function with inter-
Reliability. Cronbach’s alpha for internal consistency
was 0.85 (16). Interitem correlation for the JAFAS scores in
children with JRA was 0.36, suggesting items measure
different factors of the activity component of the Interna-
tional Classification of Functioning, Disability and Health.
No information is available on intratester or intertester
reliability or test–retest stability of the JAFAS score in
children. A recent study (17) comparing the measurement
properties of the JAFAS and the Childhood Health Assess-
ment Questionnaire (C-HAQ) in a single sample of 28
children with juvenile idiopathic arthritis reported the
internal consistency of the JAFAS (0.91) to be lower than
the C-HAQ (0.96).
Validity. Content validity. Items were selected from 3
validated measures of physical function for adults with
arthritis and reviewed by a panel of experts in JRA.
Convergent validity. Demonstrated by examining the
correlation between JAFAS scores of children with JRA
and accepted measures of disease activity; active joint
count (r ? 0.40, P ? 0.003), Steinbrocker functional class
(r ? 0.59, P ? 0.001), global disease activity score (0 ?
active, 1 ? partial remission, 2 ? total remission) (r ?
?0.32, P ? 0.01). Bekkering et al (17) reported higher
correlations between standard measures of disease activity
and the C-HAQ (rs? 0.41–0.73) then the JAFAS (rs?
0.07–0.50). One reason may be the JAFAS measures the
speed of a child’s actual performance of tasks at a specific
time point whereas the C-HAQ measures the amount of
difficulty the child had performing tasks over the previous
Ability to detect change. There is no published evi-
dence of the ability of the JAFAS to detect change in a
child’s physical function over time or with intervention.
Critical Appraisal of Overall Value to the
Strengths. The JAFAS is a quick and relatively simple
test to administer. It addresses the activity component
of the International Classification of Functioning, Disabil-
ity, and Health by measuring the child’s capacity to per-
form typical and necessary daily physical tasks. The total
JAFAS score demonstrates an acceptable relationship with
several measures of disease activity and severity, includ-
ing swollen joint count and limited joint motion. The test
may be appropriate to evaluate rehabilitation interven-
tions in children with active disease and limited joint
motion that negatively impacts their ability to perform
basic ADLs. The JAFAS may be most appropriate for chil-
dren whose joint range of motion is limited due to acute or
chronic joint inflammation and muscle weakness.
Caveats and cautions. The JAFAS measures the child’s
capacity to perform only 10 simple activities and does not
include complex motor skills required for individual or
team sports. Thus it may not be sensitive enough to detect
functional limitations that negatively impact a child’s par-
ticipation in school and community settings. This problem
will be most evident in children with mild disease and few
limitations in basic ADLs. The interrater and intrarater
reliability of the JAFAS and the stability of test results over
time have not been examined. Also, the ability of the test
to detect change in a child’s physical function over time or
with intervention has not been examined.
Clinical usability. The JAFAS takes minimal training,
equipment, and time to administer and score, thus it does
not pose a burden on either the child or tester. It can be
easily performed in a clinic or office. Clinicians can com-
pare a child’s total JAFAS score and scores on individual
test items to the criterion values for healthy children in
order to determine the need for a referral to physical or
occupational therapy for a more detailed evaluation and
Research usability. The JAFAS demonstrates adequate
validity and reliability as a measure of physical function in
children with arthritis. It is also the only measure in pe-
diatric rheumatology that measures a child’s physical ca-
pacity to perform daily activities. However, the usability of
the JAFAS in research is limited by the lack of information
on the test’s responsiveness to changes in disease status
over time or to medical or rehabilitative intervention.
PEDIATRIC OUTCOMES DATA COLLECTION
Purpose. To assess patients under the age of 19 years for
overall health, pain, and ability to participate in normal
daily activities, as well as more vigorous activities typi-
cally associated with young people. The target populations
are children and adolescents ages 2–18 years with general
health problems, specifically any problems related to bone
and muscle conditions. Originally published in 1994 (18),
and updated in 2005.
Content. Five scales provide a broad view of the phys-
ical, mental, and psychosocial status of the child and
adolescent patient. The scales are upper extremity and
physical function, transfer and mobility tasks, sports/
physical functioning, pain/comfort, treatment expecta-
tions, happiness, and satisfaction with symptoms. A
Global Functioning scale consists of the mean of the
“mean of items” values for the first 4 scales.
Number of items. Total measure: Adolescent Outcomes
Questionnaire (self report for youth 11–18 years of age) (83
items); Adolescent Outcomes Questionnaire (parent report
to be completed by a parent or guardian of a youth 11–18
years old) (86 items); and Pediatric Outcomes Question-
naire (parent report to be completed by a parent or guard-
ian of a child ?10 years) (86 items). Number of items in the
(8 items), transfers and mobility (11 items), sports and
physical function (21 items), pain/comfort (3 items), and
happiness (5 items).
Response options/scale. Most items use a categorical
scale, with a range of 3–6 choices; some items require
respondent to circle “yes” to all responses that apply to the
Recall period for items. One week for most items; one
item asks parents to indicate how often over the past 12
months the child has missed school because of health
Endorsements. American Academy of Orthopedic Sur-
Examples of use. Damiano D, Gilgannon M, Abel M.
Responsiveness and uniqueness of the Pediatric Outcomes
Data Collection Instrument to the Gross Motor Function
Measure for measuring orthopedic and neurological out-
comes in cerebral palsy. J Pediatr Orthop 2005;25:641–5.
Huffman GR, Bagley AM, James MA, Lerman JA, Rab G.
Assessment of children with brachial plexus birth palsy
using the Pediatric Outcomes Data Collection Instrument.
J Pediatr Orthop 2005;25:400–4.
Lerman JA, Sullivan E, Haynes R. The Pediatric Out-
comes Data Collection Instrument (PODCI) and functional
assessment in patients with adolescent or juvenile idio-
pathic scoliosis and congenital scoliosis or kyphosis.
Vitale MG, Levy D, Moskowelijns A, Spellman M, Ver-
disco L, Roye D. Capturing quality of life in pediatric
orthopeadics: two recent measures compared. J Pediatr
and physical function
How to obtain. Available at no cost on the AAOS
web site http://www.aaos.org/research/outcomes/outcomes_
Method of administration. Parent completes the Pedi-
atric Outcomes Questionnaire as proxy for a child, ages
2–10 years, and Adolescent (parent report) Outcomes
Questionnaire as proxy for adolescents, ages 11–18 years.
Adolescents, ages 11–18 years, complete the Adolescent
(self-report) Outcomes Questionnaire.
Scoring. Specific instructions are provided for answer-
ing each item in the questionnaires. The majority of items
are scored using a 1–5 range with 1 indicating the most
positive response (i.e., The activity is EASY for the child;
The child is VERY HAPPY; The child NEVER required
help from another person). Some items include a 6th re-
sponse choice, “Child is too young.” These items are
coded as missing and omitted from the mean score. The
AAOS web site provides a scoring worksheet in Microsoft
Excel 2003 to record raw scores for all scales. General
instructions are found on the Instructions tab. After ad-
ministering the questionnaire, one enters the data into the
worksheet on the Data Entry tab. Items with no entry are
scored as missing and omitted from the mean score for that
scale. Each worksheet includes formulae that build in any
necessary item recoding, computation of missing items,
and known general population means and SDs, as needed.
Raw scores for each scale are converted to a standard score
based on the mean of items that make up that scale. All
items in a scale are first recalibrated so they are in the same
metric, with a range of values from 0–5 for each item. Next
the scores for all items comprising a scale are averaged
over the number of items answered. The mean of the
rescaled values is then multiplied by a constant so that
each scale has a final range of values between 0–100.
Score interpretation. All standardized scores (range
0–100) are calculated in the worksheets such that higher
scores represent less disability and better functioning.
However, the user must exercise caution in interpreting
the meaning of an individual scale score. Although the
standardized scores are all in the range of 0–100, the
interpretation of a single standardized score is not consis-
tent between scales due to differences in how the general,
healthy population is scored. To make the standard scores
comparative across various scales, data from the general
US population was transformed for each scale so that the
normative score for each scale has a mean of 50 and SD of
10. Thus, a patient scoring above 50 on a particular scale is
above the general population’s average, while a patient
scoring below 50 on a scale is below the general, healthy
population’s average. To compute the individual norma-
tive score requires knowledge of the general population
mean (standardized) score and corresponding SDs. These
values are included in the instrument’s scoring worksheets
and can also be found at http://www.aaos.org/research/
outcomes/outcomes_documentation.asp#scoring. The nor-
mative score for an individual patient is calculated using
the actual mean and SD of the 0–100 scale from the gen-
eral, healthy population using the following formula: sub-
tract the general population standardized mean from each
individual’s standardized score; divide this by the general
population’s SD; multiply the resulting value by 10 and
add 50 to the resulting number. This is the final normative
score for that patient. The AAOS web site provides a clear
example of the formula.
Respondent burden. The time to complete is not spec-
ified on the web site but an estimate is approximately 15
minutes to complete all items. Although the exact reading
level is not stated, the language is fairly simple and should
be understandable for most respondents. Most items re-
quire objective responses, however a few may be emotion-
ally sensitive to parents or adolescents; for example, “Is it
easy or hard for you (your child) to make friends with
children his/her own age?”
Administrative burden. Minimal time to administer;
scoring must be done using the Excel worksheet on the
AAOS web site and may be time-consuming. Training is
not necessary, but one must follow the algorithms or for-
mulae on the scoring worksheets to recode items to a
single metric in order to calculate individual standardized
Translations/adaptations. Korean (19) and Spanish (20)
versions are available.
Method of development. The Pediatric Outcomes In-
strument Development group (pediatric orthopedists, pe-
diatric rheumatologists, and general adult orthopedists)
agreed upon important domains to measure; these in-
cluded upper and lower extremity function, ability to
perform age-appropriate activities of daily living (ADLs),
including recreation, pain or comfort, general happiness,
expectations for treatment, and satisfaction with care.
Questionnaire items were selected based on existing in-
struments, concerns of experts, and pilot testing with 112
parents and 64 adolescents (18). Clinical judgment, com-
bined with classic psychometric methods (principal factor
analysis, internal reliability, and item-total correction
analysis) was used to create subscales that represent the
domains of interest. Scales were created by averaging the
item scores. Revisions to the original version were made to
assess higher levels of physical function, including com-
petitive sports, and to include response options for all
items in each age group. The revised version was pilot
tested in 30 parents and 30 adolescents.
Acceptability. Readability of the questionnaires is ac-
ceptable. The percent of missing items among the individ-
ual scales in the parent questionnaires (for children ages
2–10 years and adolescents ages 11–18 years) ranged from
0–25, with the most missing items in the happy and sat-
isfied scale. Authors state that, despite missing responses
on individual items, there was little impact on the creation
of the scales. Most missing items were for the youngest age
group (2–5 years), with the item marked as the child being
too young for the activity. The authors do not report a
ceiling or floor effect, however they do report an age effect
in some scales, such that older patients score better than
Reliability. Internal consistency. Cronbach’s
ranged from 0.76 (child form of happiness/satisfaction
scale) to 0.95 (child form of transfers and mobility scale).
Test–retest agreement. The Pearson correlations for a
subset of parents who completed a second questionnaire 1
to 2 days after the first ranged from 0.71 (happiness and
satisfaction scale) to 0.97 (transfers and mobility scale).
Interrater agreement. Paired t-tests showed significant
differences between the responses of pairs of parents and
adolescents on all scales. In general, adolescents rated
themselves higher on every measure of physical and men-
tal health while parents had higher expectations for treat-
ment outcome. The actual differences were small, con-
sidering the 0–100 score range for each scale, however
the wide range of differences suggest that many parent/
adolescent pairs differed significantly in their assessment
of the child’s condition.
Validity. Information on the validity of the PODCI can
be found on the AAOS web site and in an article by Daltroy
et al (18).
Content validity. Questionnaire items were selected
based on their importance to patients, parents, and experts
in the field; content validity was verified through pilot
testing of the instruments.
Construct validity for the scales. For convergent valid-
ity, physician ratings of global function were moderately
to highly correlated to parent and adolescent ratings on the
global function scale (r ? 0.76), upper extremity function
(r ? 0.62), and transfers and mobility (r ? 0.75).
For divergent validity, physician ratings of patients’
function and severity of diagnosis were not correlated
to parent or adolescent ratings of comfort, happiness, or
For discriminant validity, 3 PODCI scales and the Child
Health Questionnaire (CHQ) scales of physical function
were compared, using independent t-tests, in 390 patients
grouped by diagnosis into those characterized by upper
extremity or lower extremity dysfunction, or both, omit-
ting those whose diagnosis was not clearly associated with
a specific region. Several scales discriminated between
patients with and without lower extremity dysfunction,
but the PODCI sports and physical function scale was the
strongest. Only the PODCI upper extremity function scale
discriminated between patients with and without upper
extremity problems. In multiple regression analyses, 59%
of the physician’s assessment of global function was char-
acterized by PODCI function scales plus the comorbidity
score, while the parent’s overall assessment was based
more on their perception of the child’s overall happiness
Ability to detect change. Sensitivity of the PODCI scales
to detect change over time was evaluated in several ways:
1) By correlation of change scores on the parent and phy-
sician questionnaire with parent and physician scores on a
5-point transition scale indicating change in the child’s
health status (much better to much worse) over a 9-month
time period. Results indicated both parent and physician
change score were almost completely uncorrelated with
their transition scores. Higher correlations were found be-
tween change scores on the adolescent self-report and
adolescent and physician transition scores. Adolescent
PODCI global scores and two subscale scores correlated
better with the adolescent and physician transition scores
than the CHQ. However, based on regression analysis to
understand the basis of parents’ and adolescents’ assess-
ment of overall change in the patient’s global health and
orthopedic condition, the authors concluded that much of
parent and adolescent judgment of improvement or de-
cline in function was unrelated to self-perceived measures
of current function or change from baseline. Parents and
adolescents appear to base their judgments of change on
different areas; 2) by sensitivity to change among a subset
of patients who should change the most from baseline to
followup assessment (score of ?80 on a composite score of
0–100, consisting of physician-rated function, PODCI
global function, and CHQ physical function). Comparing
outcomes in a sample of 113 subjects with data on all key
patient-report outcomes scales using t-tests, all PODCI
scales, except upper extremity function, ranked higher on
sensitivity than the CHQ physical function scale. The
PODCI global score was 2.9 times more efficient than the
CHQ at detecting change in this sample. In 49 adolescents
with baseline composite scores of ?80 and complete data
for key scales, the most sensitive scale was the PODCI
physical sports and activities scale, followed closely by
the CHQ physical function and PODCI global score; and 3)
By t-scores for sensitivity based on the severity of baseline
diagnosis. Change scores were greatest for patients with
diagnoses rated as most severe (n ? 34). PODCI global
score and 2 subscales were more sensitive to change than
the CHQ physical function scale. The PODCI upper ex-
tremity function scale discriminated best between subjects
with and without upper extremity impairments, 6.8 times
more efficient than the CHQ global function. PODCI trans-
fers and mobility scale was the best discriminator of func-
tion between groups with and without lower extremity
impairments, being 2.6 times more efficient than the CHQ
physical function scale.
Critical Appraisal of Overall Value to the
Strengths. The PODCI scales measure important ele-
ments of activity and participation (basic and instru-
mental ADLs and both recreational and competitive
sports) that may be negatively affected by disease. The
instrument shows adequate sensitivity to detect change
in physical function with interventions. The PODCI scales
have been used extensively in children with cerebral palsy
and other orthopedic disorders. Children with juvenile
arthritis were included in the development of the PODCI,
although the instruments have not been used to examine
the effectiveness of interventions in this population.
Caveats and cautions. The scoring of the PODCI scales
requires the use of a computer and the formulae for recod-
ing some items can be complicated and time-consuming.
Sensitivity to change appears to be strongest in patients
with the most severe conditions for which there may be
problems. Daltroy et al noted age effects in some scales and
strongly recommended controlling for age when using the
scales to compare outcomes in groups (18). Further testing
specifically in groups of children with rheumatic disease
should be done to confirm the instrument’s usefulness in
Clinical usability. Psychometric properties of the PODCI
may support the interpretation of scores to make decisions
for individual patients. Although the respondent burden is
minimal, the requirement for using a computer program to
score and interpret the scale scores and global score will
limit the usefulness of the instrument in the clinic.
Research usability. The PODCI demonstrates appropri-
ate psychometric properties to support use in clinical re-
search. Time for the respondent to complete the question-
naire is not prohibitive (10–18 minutes). Although scoring
of the individual scales and global scale requires the use of
a computer, this should not limit their use in research.
ACTIVITIES SCALE FOR KIDS (ASK)
Purpose. Measure physical disability and monitor func-
tional change in children ages 5–15 years experiencing
limitations in physical activities due to musculoskeletal
disorders. Originally developed in 1995 and revised in
Content. The ASK capability (ASKc) measures activities
the child “could have done” (capability) and the ASK
performance (ASKp) measures activities the child actually
“did do” over the past week. Items are organized in 7
domains that measure basic and instrumental activities of
daily living and play in children: personal care, dressing,
other skills, locomotion, play, standing, and transfers.
Number of items. Each version includes a total of 30
items: personal care (3 items), dressing (4 items), other
skills (4 items), locomotion (7 items), play (2 items), stand-
ing (5 items), and transfers (5 items). Six other information
items ask about the use of assistive devices and the amount
of assistance the child needs for activities; these items are
not included in the summary score for the scale.
Response options/scale. 5-point ordinal scale (range
0–4). The response options depend on the ASK version:
ASKc(0 ? with no problem, 1 ? with a little problem, 2 ?
with a moderate problem, 3 ? with a big problem, 4 ? I
could not); ASKp(0 ? all of the time, 1 ? most of the time,
2 ? sometimes, 3 ? once in a while, 4 ? none of the time).
Recall period for items. Previous week.
Endorsements. The ASK is not specifically endorsed by
any entity or organization, however, the instrument has
been used extensively in research involving children with
Examples of use. Moreau NG, Simpson KN, Teefy SA,
Damiano DL. Muscle architecture predicts maximum
strength and is related to activity levels in cerebral palsy.
Phys Ther 2010;90:1619–30.
Young NL, Varni JW, Snider L, McCormick A, Sawatzky
B, Scott M, et al. The internet is valid and reliable for
child-report: an example using the Activities Scale for
Kids (ASK) and the Pediatric Quality of Life Scale
(PedsQL). J Clin Epidemiol 2009;62:314–20.
Dillon ER, Bjornson KF, Jaffe KM, Hall JG, Song K.
Ambulatory activity in youth with arthrogryposis: a cohort
study. J Perdiatr Orthop 2009;29:214–7.
How to obtain. Available for purchase from the ASK de-
velopers at: http://www.activitiesscaleforkids.com/. Con-
tact information for the test developers is listed on the web
site. The cost depends on the proposed use of the instru-
ment (free for student projects and teaching purposes;
$115 [Canadian] for clinical site annual license or non-
funded academic research; $585 [Canadian] for funded
academic research; $875 [Canadian] for multisite funded
Method of administration. Mailed to the child’s home
to be completed by the child in the home because most
activities important to the child occur in the home, school,
or community. Parents may read the items to a child
younger than 9 years or those with cognitive impairments,
however the child is expected to record the response.
Scoring. A test booklet for each version (ASKpand
ASKc) includes instructions in simple, concrete language,
a scale with all possible responses and the meaning of
each response, and an instruction card the child can use
while he/she completes each item. Children are told to
complete all items. The 5-point (0–4) ordinal scale is
scored as follows: 4 points to the 1st response (0), 3 points
to the 2nd response (1), 2 points to the 3rd response (2),
1 point to the 4th response (3), 0 points to the 5th re-
sponse (4). A 6th response option, not applicable (N/A), is
not included in the computation for the summary score.
Scores on the 30 individual activity items (or the number
completed by the child minus any N/A items) are aggre-
gated into a single summary score for each version by
averaging the responses, then multiplying by 25 in order to
convert the score to a 0–100 range, where higher scores
indicate better functional outcome. Examples of the calcu-
lation are provided in the test manual.
Score interpretation. Higher scores indicate less dis-
ability or better functioning. Interpretation also depends
on the purpose of the assessment. If the purpose is assess-
ment of physical disability status, the clinician can com-
pare a child’s scores to data collected at the Hospital for
Sick Children on a sample of 200 children with musculo-
skeletal disorders. The manual provides summary data for
this sample. If the purpose is monitoring change in phys-
ical function, a change of ?5 points is considered statisti-
cally significant. Summary scores changed by 1.73 SDs in
a subsample of 34 children who were predicted by clini-
cians to make clinically important change. If the purpose
is to identify discrepancies between capability and perfor-
mance, then this may help the clinician choose areas of
function on which to focus further assessment or therapy.
Normative scores are available in an article by Plint et al,
where they examined the summary scores on the ASKp
for 122 healthy children (21). The mean ? SD score of
92.12 ? 6.45 (range 74.14–100) differed significantly from
that of a sample of children with mild (85.86 ? 13.17),
moderate (52.66 ? 22.53), and severe (21.00 ? 10.23)
Respondent burden. The ASK takes approximately 30
minutes to complete the first time, but as little as 10
minutes on subsequent administrations. Instructions,
items, and item responses are written in simple, concrete
language. It may take slightly longer if a parent needs to
read the items for a child younger than 9 years of age.
Adminstrative burden. No training is necessary to use
the ASK, however the user must read the manual and
follow directions for administration and scoring. The ASK
is mailed to the child’s home and is self-administered by
the child. A parent may read the items to the child younger
than 9 years of age, but the child must record his or her
response. Approximate time to score the instrument is 15
Translations/adaptations. The ASK web site (http://
indicates that instruments are available in several lan-
guages, including Canadian English, Canadian French, UK
English, Spanish, and Dutch. Only the Canadian English
version has been validated.
Method of development. The ASK was developed in
8 stages. The initial stage involved item generation by
children, ages 5–15 years, with diagnoses resulting in mus-
culoskeletal impairments (amputations, athrogryposis, ar-
thritis, dermatomyositis, cerebral palsy, fracture, muscular
dystrophy, scoliosis, spina bifida) and their parents. Chil-
dren were identified through various clinics at the Hospi-
tal for Sick Children (rheumatology, orthopedic, physical
therapy) and through sports camp staff. Children with
significant cognitive impairment were excluded. Parents
and children were interviewed in their home and asked to
list activities that were difficult for them (their child) to
perform and tasks the child had to stop or had never
performed. Clinicians also identified items for the scale.
Children ranked items in order of importance. Participants
were also asked to identify and rank items from other
Item reduction based on consensus by a panel of experts
using parent and child rankings resulted in 76 items, or-
ganized into 16 sub-domains. The test was formatted with
simple, concrete language in the first person and pilot
tested with 10 children. Two versions were developed, the
ASKpand ASKcand field tested with 28 children and their
parents (intertester agreement). Parents and children com-
pleted the ASK 2 weeks later to assess test–retest agree-
ment. The ASK summary scores were also compared be-
tween groups of children that referring clinicians had
rated as having mild, moderate, or severe disability, show-
ing significant differences among the groups (P ? 0.0001).
Further reduction of items was done through expert con-
sensus based on data from an exploratory Rasch analysis
(22). The original ASK versions were reduced from 73 to
53 items by removing items that did not detect disability,
were not identified as important to children, or were iden-
tified as being performed less than daily or to have always
met the child’s needs. The 53-item versions were used to
measure validity and responsiveness. Additional Rasch
analysis identified the best combination of items that max-
imized their spread along the difficulty continuum, maxi-
mized discrimination among children across the 5–15 year
age range, and provided the strongest evidence for validity
and responsiveness. This resulted in 29 items plus 1 ad-
ditional item (hand writing) organized into 9 domains.
These were reorganized into 7 domains producing the
current 30-item versions of the ASKpand ASKc.
Acceptability. The reading level is not stated, however
the authors state the test was developed using simple,
concrete language in the first person, making it easy for
most children to understand. For children younger than
the age of 9 years, parents may read the items to the child,
although the child must record his or her response in the
The instructions state the child should complete all
items. However, there is an equivalent scoring formula in
the manual that takes into account the possibility of miss-
ing items (sum of all completed items times 25 divided by
the maximum possible score for those items). Questions
not answered or that are marked N/A are not included in
either the numerator or denominator of the formula.
A ceiling effect was found in healthy children without a
musculoskeletal disorder (N ? 122), with most scores clus-
tered around the higher end of the scale. No ceiling effect
has been reported for either ASK version in children iden-
tified as having mild, moderate, or severe disability.
Reliability. ASK forms were administered by mail to 40
children and their parents. Upon return of the first ques-
tionnaire, a second form was mailed to the families to
determine test–retest reliability. Twenty-eight children
completed the first questionnaire, 18 completed the sec-
Internal consistency. Chronbach’s alpha is 0.99.
Test–retest reliability. Intraclass correlation coefficient
(ICC) 0.97 for ASKpand ICC 0.98 for ASKc.
Interrater reliability. (Child versus parent) ICC 0.96 for
ASKp, ICC 0.98 for ASKc.
Intrarater reliability. Child ICC 0.97 for ASKp, child ICC
0.98 for ASKc. Parent ICC 0.94 for ASKp, parent ICC 0.95
for the ASKc.
Validity. Content validity. The ASK was developed
through generation of items from relevant literature, chil-
dren with disabilities, their parents, and clinical experts.
A panel of experts selected final items using a consensus
approach based on the frequency of items generated by
parents and children and their ranking of items for impor-
tance. Kappa coefficient (0.70) indicated items generated
by parents and children were similar; Wilcoxon’s signed
rank test (P ? 0.055) indicated a significant difference in
the level of importance given to each activity item.
Construct validity. This was examined using several
methods in a sample of 200 children (mean ? SD age
10.1 ? 3.1 years, range 5–15 years). Convergent validity
was assessed. Spearman’s correlation between the ASK
and the Childhood Health Assessment Questionnaire
(C-HAQ) was 0.82 for the ASKpand 0.85 for the ASKc
indicating both instruments were measuring the same con-
struct, physical disability. Divergent validity assessed
through Spearman’s correlation between the ASKpand the
Health Utilities Index constructs of emotion and speech
were 0.15 and 0.09, respectively, which indicates these
instruments are measuring different constructs. Discrimi-
nant validity was determined in a study of 200 children
(mean age 10.1 years, range 5–15 years of age). Significant
differences were found in the ASKpsummary scores be-
tween children at different levels of disability according to
their clinicians’ global ratings (A analysis of variance P ?
0.0001) (23,24). Criterion validity was determined in a
sample of 24 children (mean age 10.2 ? 3.3 years) with
musculoskeletal disorders. The correlation between child
and physician ASKcscores was high, Spearman’s rho ?
0.92 (95% confidence interval 0.82–0.97). Interrater reli-
ability was also high, ICC 0.99.
Ability to detect change. Responsiveness to change was
assessed in 22 children chosen from the larger sample of
200; these children were expected to change during a
6-month period based on predictions by their clinicians.
Parents and children completed an initial ASKp, ASKc,
and the C-HAQ. Parents were contacted after 6 months to
determine if the expected change had occurred and were
sent a second set of questionnaires to complete. The stan-
dardized response mean for the 3 instruments was 1.1
(ASKp), 0.94 (ASKc), and 0.96 (C-HAQ), indicating the
ASKpwas 16% more responsive than the C-HAQ, while
the ASKcwas 2% less responsive than the C-HAQ (24).
Critical Appraisal of Overall Value to the
Strengths. The ASK measures a child’s capability and
performance of functional activities, a primary component
of the International Classification of Functioning, Disabil-
ity, and Health framework that may be impacted by
chronic rheumatic disease. The instruments have under-
gone rigorous development and psychometric testing and
demonstrate excellent reliability, validity, and responsive-
ness to change over time or with intervention. The ASK
was developed to assess physical disability in children
with musculoskeletal impairments due to orthopedic dis-
orders. It is appropriate for use in children with juvenile
idiopathic arthritis or other rheumatic diseases.
Caveats and cautions. Although the ASKp has been
shown to discriminate between levels of disability and
between children with and without musculoskeletal dis-
ability, it is not appropriate as a measure of physical dis-
ability in children without musculoskeletal impairments
due to ceiling effects in this population. This may limit the
usefulness of the ASK in children with rheumatic disease
who do not demonstrate impairments of the musculoskel-
etal system. An additional limitation is that the ASK,
similar to other instruments that assess physical function
in children, does not elicit the child’s perspective on his or
her abilities relative to other children of the same age, an
important aspect of participation.
Clinical usability. The ASK could be used to make de-
cisions for individual patients regarding the focus of fur-
ther assessment or therapy to address activity limitations.
Because the ASK is mailed to the parent and completed in
the home, there is very little administrative burden. Time
for the child to compete the ASK is not excessive.
Research usability. The psychometric properties of the
ASK support its use in research. The instrument has been
used extensively in research involving children with pri-
mary orthopedic disorders and those with musculoskeletal
impairments secondary to neurologic conditions. The ASK
requires little time for respondents to complete and mini-
mal administrative time or effort since it is mailed to
respondents and completed in the home. Scoring of each
ASK version is simple and requires little time.
Dr. Klepper drafted the article, revised it critically for important
intellectual content, and approved the final version to be pub-
1. Holsbeeke L, Ketalaar M, Schoemaker MM, Gorter JW. Capacity, capa-
bility, and performance: different constructs or three of a kind. Arch
Phys Med Rehabil 2009;90:849–55.
2. Young NL, Yoshida KK, Williams JI, Bombardier C, Wright JG. The role
of children in reporting their disability. Arch Phys Med Rehabil 1995;
3. Singh G, Athreya BH, Fries JF, Goldsmith DP. Measurement of health
status in children with juvenile rheumatoid arthritis. Arthritis Rheum
4. Huber AM, Hicks JE, Lachenbruch PA, Perez MD, Zemel LS, Ren-
nebohm RM, et al, for the Juvenile Dermatomyositis Disease Activity
Collaborative Study Group. Validation of the Childhood Health Assess-
ment Questionnaire in the juvenile idiopathic myopathies. J Rheumatol
5. Feldman BM, Ayling-Campos A, Luy L, Stevens D. Silverman ED, Laxer
RM. Measuring disability in juvenile dermatomyositis: validity of the
Childhood Health Assessment Questionnaire. J Rheumatol 1995;22:
6. Meiorin S, Pistorio A, Ravelli A, Iusan SM, Filocamo G, Trail L, et al.
Validation of the Childhood Health Assessment Questionnaire in active
juvenile systemic lupus erythematosus. Arthritis Rheum 2008;59:
7. Flato B, Aasland A, Vandvik IH, Forre O. Outcome and predictive
factors in children with chronic idiopathic musculoskeletal pain. Clin
Exp Rheumatol 1997;15:569–77.
8. Alman BA, Bhandari M, Wright JG. Function of dislocated hips in
children with lower level spina bifida. J Bone Joint Surg Br 1996;78:
9. Lam C, Young N, Marwaha J, McLimont M, Feldman BM. Revised
versions of the Childhood Health Assessment Questionnaire (CHAQ)
are more sensitive and suffer less from a ceiling effect. Arthritis Rheum
10. Groen W, Unal E, Norgaard M, Maillard S, Scott J, Berggren K, et al.
Comparing different revisions of the Childhood Health Assessment
Questionnaire to reduce the ceiling effect and improve score
distribution: data from a multi-center European cohort study of chil-
dren with JIA. Pediatr Rheumatology Online J 2010;8:16.
11. Rupeto N, Martini A. International research networks in pediatric
rheumatology: the PRINTO perspective. Curr Opin Rheumatol 2004;16:
12. Dempster H, Porepa M, Young N, Feldman BM. The clinical meaning of
functional outcome scores in children with juvenile arthritis. Arthritis
13. Takken T, van den Eijkof F, Hoijtink H, Helders PJ, van der Net J.
Examining the psychometric characteristics of the Dutch Childhood
Health Assessment Questionnaire: room for improvement? Rheumatol
14. Ouwerkerk JW, van Pelt PA, Takken T, Helders PJ, van der Net J.
Evaluating score distributions in the revised Dutch version of the
Childhood Health Assessment Questionnaire. Pediatr Rheumatol On-
line J 2008;6:14.
15. Saad-Magalhaes C, Pistorio A, Ravelli A, Filocamo G, Viola S, Brik R,
et al. Does removal of aids/devices and help make a difference in the
Childhood Health Assessment Questionnaire disability index? Ann
Rheum Dis 2010;69:82–7.
16. Lovell DJ, Howe S, Shear E, Hartner S, McGirr G, Schulte M, et al.
Development of a disability measurement tool for juvenile rheumatoid
arthritis: the Juvenile Arthritis Functional Assessment Scale. Arthritis
17. Bekkering WP, Cate RT, van Rossum MA, Vliet Vlieland TP. A com-
parison of the measurement properties of the Juvenile Arthritis Func-
tional Assessment Scale with the Childhood Health Assessment ques-
tionnaire in daily practice. Clin Rheumatol 2007;26:1903–7.
18. Daltroy LH, Liang MH, Fossel AH, Goldberg MJ. The POSNA pediatric
musculoskeletal functional health questionnaire: report on reliability,
validity and sensitivity to change. Pediatric Outcomes Instrument De-
velopment Group. Pediatric Orthopaedic Society of North America.
J Pediatr Orthop 1998;18:561–71.
19. Kwon DG, Chung CY, Lee KM, Lee DJ, Lee SC, Choi IH, et al. Trans-
cultural adaptation and validation of the Korean version of the Pediat-
ric Outcomes Data Collection Instrument (PODCI) in children and
adolescents. J Pediatr Orthop 2011;31:102–6.
20. Wren TA, Sheng M, Bowen RE, Scaduto AA, Kay RM, Otsuka NY, et al.
Concurrent and discriminant validity of Spanish language instruments
for measuring functional health status. J Pediatr Orthop 2008;28:199–
21. Plinth AC, Gaboury I, Owen J, Young NL. Activities Scale for Kids: an
analysis of normals. J Pediatr Orthop 2003;23:788–90.
22. Young NL, Williams JI, Yoshida KK, Wright JG. Measurement proper-
ties of the Activities Scale for Kids. J Clin Epidemiol 2000;53:125–37.
23. Young NL. Evaluation of paediatric physical disability and exploration
of contributing factors [PhD thesis]. Toronto: University of Toronto;
24. Young NL, Williams JI, Yoshida KK, Bombardier C, Wright JG. The
context of measuring disability: does it matter whether capability or
performance is measured? J Clin Epidemiol 1996;49:1097–101.
Summary Table for Measures of Pediatric Function*
C-HAQ Measure health
items in 8
items and no
Children ?9 years
of age complete
parent reports as proxy for child
?10–15 minutes to
?2–5 minutes to
score by hand
In original C-HAQ
the DI range 0–3
and higher scores
Strong for parent
Cronbach’s ? ?
0.9 for internal
SEM ? 2.1 for
parent and child
Excellent for content
validity; moderate to
high for criterion
validity; C-HAQ38versions demonstrate
improved ability to
and base-line DI;
ES ? 1.05;
SRM ? 1.20
Measures physical functions
that may be limited in
children with rheumatic
diseases; easy to
administer, useful in clinical and research
Original C-HAQ strong
ceiling effect that limits
usefulness in children
with mild disease and
few activity limitations;
C-HAQ38 versions show
distribution, less ceiling
effect, and improved ability to detect change
in children with mild
JAFAS Measure capacity
to perform 10
times the child
as they perform each task using
?15 minutes to
score test; training
is required but
Items scored on 0–2
ordinal scale; total
scale range 0–20;
? ? 0.85; no data
on test–retest or
Good for content
validity; fair to
to measures of disease
activity in JRA
Simple to administer and
score; total score shows
acceptable relationship to
disease activity measures;
may be useful in clinical
assessment or research to
measure effects of
intervention in children
with moderate disease
and limited ability to
perform basic ADLs
Measures only a few
activities; has limitedability to detect activity
limitations in children
with mild disease; no
evidence of ability to
detect change over time
or with intervention
PODCI Daily activities,
as proxy forchild (2–10
?15 minutes to
not stated, but
Minimal time to
using Excel work-
sheet on AAOS
web site; time to
score can be
disability. mean ?
SD of normative
score 50 ? 10
excellent (? ?
test–retest (r ?
responses on all
Content good; construct:
moderate to strong
varies by scale; able
with and without
dysfunction in lower
Sensitivity to change
among subset of
to change the most(baseline score
?80) was good to
patients with diagnosis rated as
Measures important basic
ADLs as well as sports in
children and teens with
shows adequate sensitivity to change,
especially in severe
necessary using AAOS
software; re-scoring ofsome items necessary to
scores; sensitivity to
change is strongest ingroups with most severe
changes in child’s
Mailed to child’s
home to be
completed bychild (ages 9–15
may read items
to a child ?9
years, but child
30 minutes to
10 minutes on
instructions, items, and
No training necessary,
but user must read
the manual and follow directionsfor administration
and scoring; time to
score ?15 minutes
indicate betterfunction or less
Cronbach’s ? ?
ICC 0.96, ASKc
Excellent for content,
convergent, divergent,and discriminant
SRM ? 1.1 ASKp,
SRM ? 0.94 ASKc
Measures capability and
of physical functions
impacted by orthopedicimpairments in children;
excellent psychometric attributes
May not be appropriate to
function in children
with no musculoskeletal
limitations; does not
elicit child’s perspective
on abilities relative toother children of similar
* C-HAQ ? Childhood Health Assessment Questionnaire; DI? disability index; VAS ? visual analog scale; ES ? effect size; SRM ? standardized response mean; JAFAS ? Juvenile Arthritis Functional Assessment Scale; JIA ? juvenile
idiopathic arthritis; JRA ? juvenile rheumatoid arthritis; ADL ? activities of daily living; PODCI ? Pediatric Outcomes Data Collection Instrument; ASK ? Activities Scale for Kids; AAOS ? American Academy of Orthopedic Surgeons;
ICC ? intraclass correlation coefficient.