Assessing the psychometric properties of quality of life measures in individuals with amyotrophic lateral sclerosis: a systematic review.

PURPOSE: Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease in adults. There are many patient-reported outcome measures (PROMs) for measuring quality of life (QoL) and health-related QoL (HRQoL) within this population; however, there is limited consensus regarding which are most valid, reliable, responsive, and interpretable. This systematic review assesses the psychometric properties and interpretability of QoL and HRQoL PROMs for individuals with ALS. METHODS: This review was conducted following the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) methodology for systematic reviews of PROMs. MEDLINE, EMBASE, and CINAHL databases were searched. Studies were included if their aim was to evaluate one or more psychometric properties or the interpretability of QoL or HRQoL PROMs in individuals with ALS. RESULTS: We screened 2713 abstracts, reviewed 60 full-text articles, and included 37 articles. Fifteen PROMs were evaluated including generic HRQoL (e.g., SF-36), ALS-specific HRQoL (e.g., ALSAQ-40), and individualized QoL (e.g., SEIQoL) measures. Evidence for internal consistency and test-retest reliability were acceptable. For convergent validity, 84% of hypotheses were met. For known-groups validity, outcomes were able to distinguish between healthy cohorts and other conditions. Responsiveness results ranged from low to high correlations with other measures over 3-24 months. Evidence for content validity, structural validity, measurement error, and divergent validity was limited. CONCLUSION: This review identified evidence in support of the ALSAQ-40 or ALSAQ-5 for individuals with ALS. These findings can guide healthcare practitioners when selecting evidence-based QoL and HRQoL PROMs for patients and provide researchers with insight into gaps in the literature.