352. Polypharmacy in U.S. Medicare Beneficiaries with Antineutrophil Cytoplasmic Antibody (ANCA) Vasculitis
Creators: name: Binxin Cao1
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Objective:</strong> Treatment requirements of antineutrophil cytoplasmic autoantibody vasculitis (AV) and high comorbidity burden among AV patients may lead to higher potential for polypharmacy (i.e., taking ≥5 medications concurrently) and its associated adverse outcomes, including adverse ug events, nonadherence, ug-ug interactions, and higher costs. Medication burden in AV patients has not been well-characterized. In a retrospective cohort study of a national sample of Medicare fee-for-service beneficiaries with AV, we examined prevalence of polypharmacy in the first year after diagnosis overall and among four AV subtypes (microscopic polyangiitis [MPA], granulomatosis with polyangiitis [GPA] without renal involvement, GPA with renal involvement, eosinophilic GPA [EGPA]). <strong>Method:</strong> This study used 2015-17 Medicare enrollment data, Part A and Part B medical clai, and Part D prescription ug events to identify incident cases of AV by requiring ≥1 inpatient claim or &gt;1 non-inpatient clai associated with an ICD-10-CM diagnosis code for GPA, MPA, or EGPA in 2016 and no such claim in 1 year prior. Part D records provided data on prescriptions dispensed in outpatient or long-term care settings, while Part B clai provided data on infused medications administered in outpatient settings. We calculated the 91-day period prevalence of polypharmacy (≥5 concurrent medications), by counting the number of unique medications dispensed or administered in the quarter after diagnosis. We further categorized the medication count as high- (≥10 concurrent medications) and moderate- (5 to 9 concurrent medications) polypharmacy. We also calculated the prevalence of polypharmacy for the subsequent three quarters in the first year after diagnosis. We used multinomial logistic regression to compare odds of high and moderate polypharmacy by AV subtype, adjusting for age, sex, race/ethnicity, region of country, and receipt of Medicaid or the Part D low-income subsidy. <strong>Results:</strong> We identified 1243 incident cases of AV who remained enrolled in the entire year after diagnosis; 79% were aged ≥65 years, 63% were female, 80% were white, non-Hispanic. A total of 83.8% exhibited polypharmacy in the first quarter (Q1) after diagnosis, followed by 80.5% for Q2, 78.1% for Q3, and 78.8% for Q4. The prevalence of high-level polypharmacy was 40.4% for Q1, 36.0% for Q2, 34.4% for Q3, and 33.6% for Q4. The prevalence of polypharmacy in Q1 among subtypes ranged from 82.09% in GPA without renal involvement to 88.97% in EGPA. The adjusted odds (see Table 1) of high- level polypharmacy in EGPA was higher for all four quarters compared to non-renal GPA, ranging from 1.832 (95% CI: 1.088, 3.082) in Q3 to 2.490 (95% CI: 1.428, 4.341) in Q4; odds of moderate polypharmacy were also higher in Q1 (OR=1.865, 95% CI: 1.018, 3.417). GPA with renal involvement had higher odds of moderate polypharmacy than GPA without renal involvement in Q3 (OR=1.883, 95% CI: 1.231, 2.880) and Q4 (OR=2.144, 95% CI: 1.385, 3.321). MPA patients exhibited no significant differences in polypharmacy across quarters when compared to GPA without renal involvement. <strong>Conclusions:</strong> The vast majority of U.S. Medicare beneficiaries with newly diagnosed AV had polypharmacy, with &gt;40% taking 10 or more medications. Polypharmacy was more common in EGPA and GPA with renal involvement, compared to GPA without renal involvement. <strong>Disclosures</strong>: None