Peer-reviewed article
The QOLA study: psychometric validation of the Quality of Life of Parents of Children with Achondroplasia (QOLA) questionnaire - a multinational study in Germany, Italy, and Portugal.
Adekunle Adedeji, Stefanie Witt, Lea Maric, Maria Salomao, Florian Innig et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study validates a questionnaire (QOLA) designed to measure the quality of life of parents whose children have achondroplasia, a genetic condition affecting bone growth. The questionnaire was tested with 149 parents across Germany, Italy, and Portugal. The final version contains 20 items organized into three domains covering healthcare trust, caregiving burden, and worries about the future. The questionnaire showed good reliability and consistency across the three countries.
Key points
- The 43-item QOLA was reduced to a 20-item version with three factors through factor analysis
- Eight-domain scores showed internal consistency (Cronbach's α = 0.706-0.905)
- Three-factor model demonstrated strong reliability (α = 0.852-0.918) and good test-retest stability (ICC = 0.801-0.877)
- Convergent validity supported by correlations with generic quality of life measure (r = 0.15-0.69)
- Results were consistent across Germany, Italy, and Portugal
Limitations
The study focuses on parental quality of life rather than child well-being outcomes, and achondroplasia is a rare genetic condition affecting a small population. The study does not evaluate interventions or policies aimed at improving child or family outcomes.
Abstract
BACKGROUND: Parents of children with achondroplasia experience multidimensional impacts on quality of life (QoL), yet validated condition-specific instruments for assessing these outcomes across countries are scarce. This study evaluated the psychometric properties of the Quality of Life of Parents of Children with Achondroplasia (QOLA) questionnaire in three European settings. METHODS: A multinational, multicentre observational psychometric validation study was conducted in Germany, Italy, and Portugal. Parents/primary caregivers (N = 149) completed the 43-item QOLA (eight conceptual domains) and the EUROHIS-QOL-8 at baseline (T1); a subsample completed follow-up assessments (T2; n = 77) for test-retest analyses. Data quality (missingness, floor/ceiling effects), internal consistency (Cronbach's α; composite reliability), temporal stability (Pearson correlations; intraclass correlation coefficients), and convergent validity (correlations with EUROHIS-QOL-8) were examined. Exploratory factor analysis informed item reduction and domain aggregation, followed by confirmatory factor analysis of the reduced model. RESULTS: Item-level missingness was minimal, and no substantial floor/ceiling effects were observed. Eight-domain scores showed acceptable to excellent internal consistency (α = 0.706-0.905) and moderate-to-good temporal stability (single-measure ICCs = 0.64-0.75). Convergent validity was supported by negative associations between QOLA domains and generic QoL (r = .15-0.69). Exploratory and confirmatory analyses supported a parsimonious three-factor, 20-item model, comprising Healthcare System Trust, Caregiving Burden and Daily Impact, and Worries About the Future and Social Relationships, with acceptable fit (CFI = 0.935, TLI = 0.925, RMSEA = 0.066), strong reliability (α = 0.852-0.918; CR = 0.864-0.914), and good test-retest stability (r = .670-0.782; average-measure ICCs = 0.801-0.877). CONCLUSIONS: The QOLA demonstrates robust reliability and validity across three countries and offers both an eight-domain profile and a three-factor summary for assessing parental QoL in achondroplasia.