Therapeutic plasma exchange in people with multiple sclerosis: A province-wide study.

OBJECTIVE

To investigate trends in TPE use and its association with social determinants of health (SDOH) using province-wide health administrative data in Ontario, Canada.

METHODS

We conducted a cohort study of patients with MS diagnosed between April 1, 1990, and March 31, 2023. We ascertained TPE use based on physician claims data. We examined trends in TPE use and used multivariable cause-specific models to evaluate the association between age, sex, rural residence, immigration status, and neighbourhood-level income and the time from first demyelinating attack to the receipt of TPE.

RESULTS

Of the 52,892 people with MS (69.8% female), 593 (1.1%) received TPE at least once; a crude rate of 6.9 (95% confidence interval: 6.3-7.4) per 10,000 person-years, with near tripling of the rate 2017-18 onwards (from 3.8 to 12.8/10,000 person-years). Females (HR 0.80; 0.69-0.94) and those residing in rural Ontario (HR 0.76; 0.59-0.98) had lower rates of TPE, whereas immigrants (hazard ratio 1.29; 1.04-1.61) and younger adults (HR 2.01; 1.65-2.44) had higher rates of TPE in the adjusted models.

CONCLUSIONS

The rate of TPE use for MS has risen substantially in recent years, yet social factors were associated with uneven utilization. Future work that accounts for disease activity, the type of relapse, and the use of disease-modifying therapy could help determine whether the observed differences represent clinical differences or healthcare disparities.