Page 176 - Let them speak Towards a patient reported outcome measure set for

Chapter 7
Caregivers and adults were informed about the study through healthcare
professionals (e.g., ID physician, pediatrician, clinical geneticist) affiliated
with ID care organizations (e.g., ‘s Heeren Loo, Prinsenstichting) and/
or academic hospitals (e.g., Amsterdam UMC, UMC Utrecht). Additional
recruitment occurred via LinkedIn and Dutch patient organizations (e.g.,
ZeldSamen, Stichting 22Q11), directing interested individuals to self-register
on the research website (www.prom-zeldzaam.nl). Following registration,
participants received an information letter and a personalized login code via
email. Written consent was obtained electronically on the research website.
Participants were asked to complete the questionnaires at baseline (T0)
and after two weeks (T1), following a second invitation email.
Measurement instruments
Sociodemographic questionnaire
Caregivers completed a sociodemographic questionnaire, which collected
information about the affected individual (e.g., age, diagnosis, level of
functioning).
GenID core PROM set
Table 1 presents the selected core PROM set for caregivers of children with
GenID, adults with GenID, and caregivers of adults with GenID. The version
number, target respondents of each PROM, the number of items for SFs,
and the specific item for single-item PROMs are provided in Additional file
1.
The core PROM set comprised primarily of PROMIS item banks, administered
as CATs (30, 31). CATs for adults and their caregivers terminated once
a standard error ≤ 2.2 was reached (indicating 95% reliability) or after a
maximum of 12 items (except for PROMIS CAT Physical Function, which
was terminated after a maximum of 13 items). CATs for caregivers of
children terminated once a standard error ≤ 3.2 was reached (indicating
90% reliability) or after a maximum of 12 items. The set also included two
PROMIS SFs, Anger and Cognitive Function/Cognitive Function –Abilities,
each containing 5 – 8 items, for which no PROMIS CATs were available.
We gave preference to PROMIS CATs, as their items are tailored to the
responder’s level of functioning. PROMIS instruments use a 5-point Likert
174