Peer-reviewed article
Assessing signs and impacts of achondroplasia: psychometric evaluation of the Achondroplasia Child Experience Measures.
Brod M, McLeod L, Smith A ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This paper describes the development and testing of measurement tools (ACEMs) to assess signs and impacts of achondroplasia, a genetic skeletal disorder, in children aged 2 to 12 years. The study evaluated the reliability and validity of these observer-reported outcome measures using data from an observational study and a clinical trial of an experimental treatment. The final tools consist of an 8-item signs measure and a 25-item impacts measure, both found to have acceptable psychometric properties. These measures are intended for use in clinical and research settings to evaluate treatments and understand children's experiences with achondroplasia.
Key points
- Achondroplasia is the most common genetic form of skeletal dysplasia with wide-ranging clinical manifestations
- Two condition-specific observer-reported outcome measures were developed: ACEM-OSM (8 items) and ACEM-Impact (25 items)
- Psychometric evaluation used data from 200 children in an observational study and 57 in a randomized controlled trial
- Both measures demonstrated acceptable reliability and validity for their intended use
- The measures can help assess new treatments and improve understanding of children's experiences with achondroplasia
Limitations
This document focuses on measurement tool development rather than evaluating actual health or well-being outcomes for children with achondroplasia. It does not provide evidence about whether specific interventions improve children's lives or how many children are affected by this rare condition.
Abstract
Background Achondroplasia, although rare, is the most common genetic form of skeletal dysplasia and is associated with a wide range of clinical manifestations and complications throughout the body. This study evaluated the psychometric measurement properties of the Achondroplasia Child Experience Measures (ACEMs), which were previously conceptually developed as condition-specific, observer-reported outcome measures to assess the signs (ACEM-OSM) and impacts (ACEM-Impact) of achondroplasia in children aged 2 to < 12 years. Methodology Data for the psychometric evaluation were from a non-interventional, observational study (N = 200 (impacts) and N = 148 (signs)) and a phase 2, multicenter, double-blind, randomized, placebo-controlled, dose escalation interventional trial (N = 57) of navepegritide (TransCon CNP) administered once weekly. The larger observational study sample size allowed for evaluation of distributional properties, test-retest reliability, and construct validity. Trial data was analyzed to confirm reliability and validity findings and evaluate responsiveness. Results Factor analysis and qualitative results identified six domains for the ACEM-Impact and one domain for the ACEM-OSM. The psychometric properties of both measures were found to be acceptable for reliability and validity for the intended use. An 8-item ACEM-OSM and a 25-item ACEM-Impact were finalized. Conclusions The ACEMs are reliable and valid measures of the signs and impacts of achondroplasia on children. Incorporation of these measures in clinical and research settings can aid in assessing new treatments and improve our understanding of the experience of those living with achondroplasia. Trial registration National Institutes of Health Clinicaltrials.gov (ID NCT04085523) and European Union Drug Regulating Authorities Clinical Trials database (EudraCT 2019-002754-22).