Patient experience and clinical outcome assessment validity in amyotrophic lateral sclerosis: a targeted literature review

To identify relevant concepts of measurement for people with amyotrophic lateral sclerosis (ALS) and to evaluate the face and content validity of clinical outcome assessments (COAs) that can be used to measure treatment benefits in ALS clinical trials. A targeted literature review was conducted to explore patient experience (stage 1) and COAs used in ALS research (stage 2). Abstracts were screened against predefined eligibility criteria; full-text articles were reviewed for eligible abstracts and relevant data were extracted. Face and content validity of the identified COAs were assessed. Stage 1 searches identified 3,527 abstracts, of which 12 full-text articles, two summary reports, and one conference poster were included in this review. Twenty-five symptoms and 35 health-related quality of life (HRQoL) impacts were identified. Frequently reported symptoms included breathing and speech difficulties and muscle/limb weakness, each associated with a diverse range of impacts, including those related to emotional wellbeing, physical function, social and leisure activities, and activities of daily living. Stage 2 searches identified 119 COAs, of which 28 were reviewed. Many had acceptable face (13/28) and content validity (15/28), but 13 had not involved patients during development; only 10 were clearly worded and seven were lengthy, increasing patient burden risk. This review identified wide-ranging symptoms and HRQoL impacts experienced by people with ALS, but detailed qualitative evidence is sparse. Multiple COAs were identified as potential measures in ALS clinical trials.