Polypharmacy prevalence, associated factors, and changes over time in Australians with multiple sclerosis

Area of Science:

• Neurology
• Pharmacology
• Public Health

Background:

• People with multiple sclerosis (PwMS) have a high risk of polypharmacy, defined as using multiple medications, due to symptom management and comorbidities.
• Limited research exists on polypharmacy patterns and trends within the PwMS population.

Purpose of the Study:

• To investigate the prevalence, contributing factors, and temporal trends of polypharmacy among Australians diagnosed with multiple sclerosis.
• To identify specific demographic and clinical factors associated with polypharmacy in this cohort.

Main Methods:

• Utilized data from the Australian Multiple Sclerosis Longitudinal Study and Pharmaceutical Benefits Scheme (PBS) datasets (2017-2022).
• Defined polypharmacy as using five or more medications prescribed at least four times annually.
• Employed log-binomial and Poisson regression models to analyze prevalence, associated factors, and annual changes in polypharmacy.

Main Results:

• In 2022, 24% of PwMS experienced polypharmacy (22% low-to-moderate, 3% hyper-polypharmacy).
• Higher age, disability, comorbidity count, and lower education were linked to increased polypharmacy likelihood.
• Conditions like type 2 diabetes, hypertension, high cholesterol, and depression were associated with higher polypharmacy prevalence. Polypharmacy increased by an average of 4.51% annually.

Conclusions:

• Polypharmacy is a prevalent and growing issue for people with multiple sclerosis in Australia.
• Older PwMS with higher disability, increased comorbidities, and lower educational attainment require targeted medication reviews to optimize care and safety.