OBJECTIVES

To assess disease related factors influencing the health related quality of life (HRQoL) in patients with secondary progressive multiple sclerosis (SPMS) patients from EXPAND trial.

METHODS

EXPAND is multicentre, double-blind, phase 3 placebo controlled trial including 1,651 participants (39.9% males) with mean age of 48 years with 1,105 SPMS patients receiving siponimod treatment and 546 patients receiving placebo. Various patient and disease specific parameters, Expanded Disability Status Scale (EDSS) to assess disability, EuroQoL 5-dimension three level (EQ-5D-3L) to assess HRQoL and Symbol Digit Modalities Test (SDMT) to assess attention, concentration and processing speed were recorded in patients at regular intervals. A mixed model repeated measures linear regression analysis was conducted to understand the factors influencing HRQoL in SPMS patients. Statistical analyses were performed using R 3.5.2 (R Core Team, 2018).

RESULTS

The mixed model revealed that disability and relapse are negatively associated with HRQoL. In comparison to lower EDSS states, higher disability states are associated with lower HRQoL. Baseline SDMT scores were found to be positively associated with HRQoL (co-efficient: 0.001, p<0.001). Higher duration of MS was also found to be positively associated with HRQoL (co-efficient: 0.002, p<0.001). HRQoL estimated using marginal means method revealed that patients receiving siponimod have higher HRQoL than placebo over time after varying treatment wise SDMT scores and adjusting for all other covariates used in the regression model. Correlation between EDSS states and SDMT was found to be weak.

CONCLUSIONS

This study demonstrates that there are factors (duration of disease and SDMT) other than disability and relapse that significantly influence HRQoL of patients with SPMS and further research can provide better insights about their impact on HRQoL. Therefore, close monitoring and early management of disability and cognition in SPMS patients may lead to better HRQoL.