Validated Measure Assesses the Impact of Treatment for Growth Hormone Deficiency in Children

A psychometric validation of the observer-reported outcome (ObsRO) of the Growth Hormone Deficiency-Child Impact Measure (GHD-CIM) found it is a valid and reliable measure that can provide a patient-centric picture to the experience children have with growth hormone therapy, according to a study published in PharmacoEconomics – Open.

GHD-CIM is a 33-item measure intended to have 2 options: a patient-reported outcome (PRO) for children with GHD aged 9 to 13 years and an ObsRO to be completed by the guardians of children with GHD between the ages of 4 and 9 years.

First, the researchers recruited 243 participants to take part in the validation survey. There were 145 children between the ages of 9 and 13 years who answered their own PRO and 98 parents/guardians who answered about the ObsRO.

“The initial review of the validation study data found that the child data had high ceiling effects not seen in the observer data….it was determined that a PRO version for children aged 9 to < 13 years was not psychometrically sound and therefore the decision was made to have only an ObsRO measure of the GHD-CIM,” the authors explained.

The mean age of the child for the participating guardians was 6.7 years. The children were mostly White (82.7%) and male (65.3%). The mean age at diagnosis was 5.1 years, and the mean age when the child started taking GHD medication was 5.2 years. The majority of children (79.6%) used a pen for medication injection and had no other health conditions (53.1%).

At baseline, participants completed a validation battery that included sociodemographic items, medical history, the GHD-CIM, the Patient Global Impression of Severity (PGIS), and more. Clinicians completed the Clinician Global Impression of Severity (CGIS).

Factor analyses identified 3 domains: physical functioning (PHYS), social well-being (SWB), and emotional well-being (EWB). The GHD-CIM is scored by adding together each domain and converting to a scale from 0 to 100 points. Higher scores represent a greater impact.

Treatment-naive participants who completed the follow-up assessment 12 weeks post baseline showed improvements in SWB, EWB, and overall scores. There was no improvement over 12 weeks in the PHYS domain.

GHD-CIM scores were calculated for groups who had a 1- to 2-point improvement in the PGIS and CGIS. Changes in the GHD-CIM total and domain scores were larger for the 2-category improvements vs the 1-category improvement.

According to the study authors, the GHD-CIM ObsRO is a validated tool that can be useful for clinicians to monitor patients and assess the impact of treatment. The simple score can be recorded and the measure repeated, providing the clinician with quality-of-life (QOL) data and an annualized height velocity as a primary end point.

“As new long-acting GH therapies are currently in clinical trials, a QOL measure would also serve as additional clinical data,” the authors wrote. “Additionally, the GHD-CIM is intended to be used in research to assess the impact of new therapies and better understand the burden of disease.”

Reference

Brod M, Højby Rasmussen M, Vad K, et al. Psychometric validation of the Growth Hormone Deficiency-Child Impact Measure (GHD-CIM). Pharmacoecon Open. 2021;5(3):505-518. doi:10.1007/s41669-020-00252-5