Perceived impact of disease modifying therapies on pain in people with multiple sclerosis: A mixed methods study

BACKGROUND: Many people with MS (PwMS) experience significant, and often complex pain symptoms. Disease-modifying therapies (DMTs) have the potential to influence the pain pathophysiology via modulating inflammatory pathways. This mixed-methods study examined the perceived impact of DMTs on pain. METHODS: Participants from the Australian MS Longitudinal Study (AMSLS) with regular pain and who had ever used DMTs (n = 764) were asked whether ever used or currently used DMTs increased or decreased pain. DMTs were grouped by mode of administration, efficacy category, and mode of action. Quantitative data was analysed using descriptive statistics. Qualitative data from six focus groups (n = 26) were analysed using thematic analysis. RESULTS: Seventy percent of people who had ever used DMTs reported no change in pain or didn't know, and 87.2% of those currently using a DMT reported it had no impact or they were not sure. Of those who ever used DMTs and reported a change, infusion DMTs were more frequently reported to decrease pain, and injectable DMTs to increase pain, but no difference was observed with currently used DMTs. Qualitative data showed little evidence that DMT usage was linked to the lived experience of pain. CONCLUSIONS: With a significant majority of participants not experiencing a change in their pain due to DMT use, the choice of DMT should not be influenced by a possible effect on pain. Additionally, as most DMTs affect the immune component of MS, it is unlikely that pain in PwMS is directly modulated by active immune/inflammatory processes.