Page 170 - Let them speak Towards a patient reported outcome measure set for

Chapter 7
Abstract
Introduction Individuals with (genetic) intellectual disabilities (GenID)
experience substantial challenges in their daily functioning. Patient reported
outcome measures (PROMs) evaluate these challenges from the patient
perspective. Currently, many PROMs with often unclear suitability are used
for individuals with GenID. This study was the first psychometric evaluation
aimed at selecting a GenID core PROM set and assessing its reliability,
efficiency, and construct validity in a Dutch sample.
Methods Caregivers of children, adults, and caregivers of adults were
recruited. Participants completed the core PROM set and legacy
questionnaires at baseline and after two weeks. Reliability was assessed
using mean standard error (SE) for PROMIS Computerized Adaptive
Tests (CATs) and short forms (SFs), and Cronbach’s alpha for subscales
of selected legacy questionnaires. Efficiency (i.e., number of items and
floor and ceiling effects) was evaluated for the core PROM set and legacy
subscales. Test–retest reliability of the core PROM set was examined using
intraclass correlation coefficients (ICCs). Construct validity was evaluated
by Pearson correlations between the core PROM set and associated legacy
subscales.
Results In total, 40 caregivers of children, 37 adults, and 44 caregivers
of adults participated. Most PROMIS CATs and SFs met the reliability
threshold (SE ≤ 3.2; 90% reliability). Most legacy subscales for adults
and caregivers of adults showed sufficient reliability (α > 0.70), whereas
more than half of the legacy subscales for caregivers of children showed
insufficient reliability (α = 0.36 – 0.67). No floor or ceiling effects occurred
for PROMIS CATs and SFs, whereas several occurred in legacy subscales
for caregivers of adults. Test–retest reliability was sufficient for most
PROMIS instruments (ICC ≥ 0.70), but varied for single-item PROMs (ICC
= 0.25 – 0.83). Most correlations between the core PROM set and legacy
subscales were moderate to high.
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