Page 216 - Let them speak Towards a patient reported outcome measure set for

Chapter 8
The core PROM set
Many and potentially unsuitable PROMs were used for individuals with
GID in research. In GID care, PROM use was limited. ObsROMs, such as
the Aberrant Behavior Checklist or the Vineland Adaptive Behavior Scales,
are more commonly used. These instruments capture observable health-
related behaviors reported by caregivers, but do not include the perspective
of individuals with GID on their own health.
In selecting the core PROM set, we aimed to include a set applicable to
all individuals with GID. We prioritized questionnaires that were generic,
brief, easy to complete, available in Dutch, suitable for both children and
adults, offered in both self- and proxy-report formats, and either free or low-
cost. The core PROM set mainly consists of PROMIS instruments, which
are well established for their good psychometric properties in both clinical
and general populations, while placing minimal burden on respondents by
assessing only a limited number of items (26). The core PROM set aligns
with the core PROMIS instruments (27), the Dutch generic core PROM
set recommended for use in medical care in the Netherlands (5, 28), and
partly with the ICHOM Set of Patient-Centered Outcome Measures for
Neurodevelopmental Disorders (29). By adhering to the predefined PROM
criteria, we excluded PROMs that did not meet these criteria, despite their
potential usefulness for specific subgroups. For example, the Glasgow
Anxiety Scale and ADAMS are designed and psychometrically tested
for adults with ID (30, 31), but are long and restricted to this population,
limiting comparability with other PROMs. Nevertheless, these instruments
were included in a separate, broader psychometric project to allow future
comparison of these instruments with the core PROM set.
We evaluated the psychometric properties (internal consistency, test-rest
reliability, and construct validity) of the core PROM set in the GID population.
Including all age groups proved challenging; ultimately, only caregivers of
children, adults, and caregivers of adults had sufficient sample sizes for
inclusion. When evaluating the psychometric properties in these three
groups, we found the set to be overall reliable and more efficient than most
commonly used legacy questionnaires, including the Pediatric Quality of
Life Inventory (PedsQL), SF-36, CBCL, Adult Self-Report (ASR), and Adult
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