Clinical trial evidence of quality-of-life effects of disease-modifying therapies for multiple sclerosis: a systematic analysis

Abstract

Background Increasingly, patients, clinicians, and regulators call for more evidence on the impact of innovative medicines on quality of life (QoL). We assessed the effects of disease-modifying therapies (DMTs) on QoL in people with multiple sclerosis (PwMS). Methods Randomized trials assessing approved DMTs in PwMS with results for at least one outcome referred to as “quality of life” were searched in PubMed and ClinicalTrials.gov. Results We identified 38 trials published between 1999 and 2023 with a median of 531 participants (interquartile range (IQR) 202 to 941; total 23,225). The evaluated DMTs were mostly interferon-beta (n = 10; 26%), fingolimod (n = 7; 18%), natalizumab (n = 5; 13%), and glatiramer acetate (n = 4; 11%). The 38 trials used 18 different QoL instruments, with up to 11 QoL subscale measures per trial (median 2; IQR 1–3). QoL was never the single primary outcome. We identified quantitative QoL results in 24 trials (63%), and narrative statements in 15 trials (39%). In 16 trials (42%), at least one of the multiple QoL results was statistically significant. The effect sizes of the significant quantitative QoL results were large (median Cohen’s d 1.02; IQR 0.3–1.7; median Hedges’ g 1.01; IQR 0.3–1.69) and ranged between d 0.14 and 2.91. Conclusions Certain DMTs have the potential to positively impact QoL of PwMS, and the assessment and reporting of QoL is suboptimal with a multitude of diverse instruments being used. There is an urgent need that design and reporting of clinical trials reflect the critical importance of QoL for PwMS.