Abstract
PURPOSE: Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative condition with swift progression. The devastating impact of ALS affects the health-related quality of life (HRQoL) of informal carers. Various person reported outcome measures (PROMs) have been used to assess HRQoL in informal carers in ALS, yet their validity remains unclear. This review aimed to identify and evaluate the content validity of HRQoL PROMs for informal carers in ALS. METHODS: This review was conducted according to best practice COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology. Two literature searches were conducted in November 2023 and April 2024 across MEDLINE, PsycINFO, Embase, CINAHL, the Cochrane Database of Systematic Reviews, CENTRAL and Google Scholar, to identify HRQoL PROMs used with informal carers in ALS, PROM development articles, and psychometric literature. Evidence synthesis followed COSMIN guidance. RESULTS: 12,276 articles were screened, and 109 PROMs were identified, with 43 undergoing full COSMIN assessment. Content validity ratings were 'Inconsistent' or 'Insufficient' for all PROMs. All PROMs, except the CarerQoL, were rated 'Insufficient' for comprehensiveness. Only 18.6% of PROMs included informal carers in development. Quality of evidence supporting content validity ratings was 'Very Low' for 93% of PROMs. CONCLUSION: HRQoL PROMs used with informal carers in ALS lack evidence to support their content validity, restricting their utility for this purpose. Existing literature on the impact of caring in ALS on informal carers' HRQoL should be interpreted cautiously. Further research is required to establish the content validity of HRQoL PROMs used for this cohort.