The PedsQL
Measurement Model is a modular
approach to measuring health-related quality of life (HRQOL) in children
and adolescents. The PedsQL consists of brief,
practical, generic core scales suitable for use with healthy school and
community populations, as well as with pediatric populations with acute
and chronic health conditions. PedsQL
condition-specific modules complement the generic core scales for use
in designated clinical populations.
Pediatric HRQOL measurement instruments must be sensitive to cognitive
development and must include both child self-report and parent proxy-report.
Accordingly, the PedsQL Measurement Model
consists of developmentally appropriate forms for children ages 2-4, 5-7,
8-12, and 13-18 years. Pediatric self-report is measured in children and
adolescents ages 5-18 years, and parent proxy-report of child HRQOL is
measured for children and adolescents ages 2-18 years.
Pediatric HRQOL instruments must have a clear conceptualization of the
HRQOL construct for pediatric populations. A pediatric
HRQOL instrument must be multidimensional, consisting at a minimum of the
physical, mental, and social health generic core dimensions delineated by
the World Health Organization (WHO) in 1948. The 23-item
PedsQL Generic Core Scales were designed to
measure these core dimensions of health as delineated by the WHO, as well
as role (school) functioning. Thus, the multidimensional
PedsQL Generic Core Scales encompass the
essential core domains for pediatric HRQOL measurement: 1) Physical
Functioning (8 items), 2) Emotional Functioning (5 items), 3) Social
Functioning (5 items), and 4) School Functioning (5 items).
While debate continues as to the relative merits of a generic versus a
disease-specific approach to measuring HRQOL, recent conceptual models
indicate the advantages of an integrated modular approach to HRQOL
measurement. The PedsQL Measurement
Model integrates seamlessly both generic core scales and disease-specific
modules into one measurement system. The
PedsQL Generic Core Scales are designed to
enable comparisons across patient and healthy populations. The
complementary PedsQL chronic health conditions
modules are designed to provide greater measurement sensitivity for
circumscribed clinical populations. PedsQL
Disease-Specific Modules are available for asthma, arthritis, cancer,
cardiac disease, and diabetes, with additional modules in the planning
stages. Thus, the PedsQL Measurement Model
combines the clinical utility and sensitivity of a disease-specific
measure and the applicability of generic core scales across patient and
healthy populations, with healthy population norms for benchmarking
purposes and community health comparisons.
The PedsQL builds on and expands a programmatic
instrument development effort by Varni and his associates during the past
15 years in pediatric populations. The PedsQL 1.0,
originally derived from a pediatric cancer database, was
designed as a generic quality of life inventory to be utilized
noncategorically, i.e., across multiple pediatric populations.
Given that instrument development is an iterative process, the
PedsQL 2.0 and 3.0 were further advancements in
the measurement model, including additional constructs and items, a more
sensitive scaling range, and a broader age range for patient self-report
and parent proxy-report. The PedsQL
has resulted from our rapid cycle improvement strategy, and has been field
tested with children and adolescents in pediatrician's offices, hospital
specialty clinics, and community settings. The PedsQL
Generic Core Scales are currently in use in several school districts
nationwide, as well as by State Departments of Health as a way of monitoring
the health of large populations of healthy and ill children. Clinical
trials and treatment interventions utilizing the
PedsQL are in the planning stages internationally.
The PedsQL has been translated into numerous
international languages.
The PedsQL Generic Core Scales represent a
substantive advancement in the PedsQL Measurement
Model, with the initial field trial demonstrating excellent measurement
properties in a physically healthy pediatric population. The field trial
was undertaken to assess the reliability, validity, responsiveness, and
practicality of the PedsQL Generic Core Scales
in both physically healthy pediatric populations and in pediatric acute
and chronic health conditions. A large sample of children and
adolescents and their parents were administered the 23 items of
PedsQL Generic Core Scales, which are printed
on one side of one sheet of paper, with the instructions on the other side.
Each PedsQL age-appropriate form takes less
than four minutes to complete. This sample included self-reports for
children and adolescents aged 5 to 18 years and proxy-report from parents
of children aged 2 to 18 years.
Internal consistency reliability of the PedsQL
was excellent, with alphas for the generic core scales in both self-
and proxy-report greater than the 0.70 standard, and alphas for the full
23-item scale approaching 0.90 for self- and proxy-report.
Missing data were minimal. Item response distributions were
across the full scale range, with no floor effects, and minimal ceiling
effects.
The validity of the PedsQL Generic Core
Scales was demonstrated through known groups comparisons, and
correlations with other measures of disease burden. The
PedsQL self- and proxy-report distinguished
between children with and without a chronic health condition, and
within the group of children with a chronic condition, between those
who did or did not have an overnight hospital visit in the last 12 months.
Further, both child self-report and parent proxy-report correlated
significantly with the number of days the child was too ill to pursue
normal activities, needed someone to care for him or her, missed school
in the last month, the number of days the parent missed from work in the
last month, and parent-report of problems pursuing their normal work
routine and concentrating at work. The PedsQL
Generic Core Scales are also responsive to clinical change, as
demonstrated in field trials.
The PedsQL Measurement Model represents a
significant advancement in pediatric HRQOL measurement, combining the
reliability, validity, responsiveness, and practicality not typically
found all in one pediatric HRQOL instrument. Researchers,
policy-makers, providers, and health plans will find the
PedsQL a welcomed addition to pediatric
health outcomes evaluation.
