To describe pharmacist interactions among Medicare Fee-for-Service (FFS) beneficiaries with myasthenia gravis (MG), using documented medication management services (MMS: Medication Therapy Management [MTM] or Evaluation and Management [E/M] encounters) and prescription fills as proxies.

Pharmacists are underutilized in chronic disease management. They are highly trained and uniquely positioned to optimize medication use, improve therapeutic outcomes, and reduce adverse events for individuals with complex regimens, like myasthenia gravis (MG).

A retrospective observational cohort study was conducted using 100% Medicare FFS Parts A, B, and D claims during January 1, 2018- December 31, 2021. Beneficiaries were included if they had ≥1 inpatient or ≥2 outpatient claims for MG (ICD-10-CM G70.xx), were aged ≥18 years, had continuous enrollment during the 12-month baseline period, and no evidence of clinical trial participation. Pharmacist interactions were estimated from Medicare Part D dispensing events and vaccinations administered at the pharmacy. Descriptive statistics summarized demographics, clinical characteristics, service uptake, and engagement. Multivariable zero-inflated negative binomial models examined factors associated with pharmacist interactions.

Among 32,200 eligible beneficiaries (mean age: 74.9 years; 48.1% female) during the 12-month baseline period, beneficiaries filled an average of 53.1 (SD: 32.5) prescriptions per patient per year (PPPY). Using a proxy definition, 99.3% of beneficiaries were MTM-eligible yet, there were only 60 unique MMS recipients. At 24 months post-index, beneficiaries had a cumulative mean of 198.7 prescription fills for any medication and 70.4 for MG-related medications. Additionally, 73.9% received flu or COVID-19 vaccinations at the pharmacy. In adjusted models MG-specific fills showed a 7.3-fold higher rate among those aged 18–29 (95% CI: 5.9–8.9; p < 0.0001), while males had 4.1% more MG-specific fills than females (95% CI: 1.02–1.06; p<0.0001).

The high frequency of pharmacy interactions, related to prescription fills and pharmacy administered vaccinations, highlights missed opportunities for pharmacist engagement to improve medication optimization.