Coccidioides Serologic Screening Practices in Individuals With Rheumatic and Autoimmune Diseases

Objective: We aimed to estimate Coccidioides serologic screening rates before initiation of biologic disease-modifying antirheumatic drugs including tofacitinib (b/tsDMARDs), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), and/or noninhaled corticosteroids. Methods: This retrospective cohort study used 2011 to 2016 US Medicare claims data and included beneficiaries with rheumatic or autoimmune disease residing in regions within Arizona, California, and Texas endemic for Coccidioides spp. with ≥1 prescription for a b/tsDMARD, csDMARD, and/or noninhaled corticosteroid. We estimated prior-year serologic screening incidence before initiating b/tsDMARDs, csDMARD, and/or noninhaled corticosteroid. Results: During 2012 to 2016, 4,331 beneficiaries filled 64,049 prescriptions for b/tsDMARDs, csDMARDs, and noninhaled corticosteroids. Arizona's estimated screening rate was 20.1% (95% confidence interval [95% CI] 14.5–25.7) in the year before prescription initiation for b/tsDMARDs, 8.1% (95% CI 6.5–9.7) before csDMARDs, and 6.9% (95% CI: 5.6–8.2) before corticosteroids. Screening rates for b/tsDMARDs (2.8%, 95% CI 0.0–6.7), csDMARDs (1.0%, 95% CI 0.0–2.0), and corticosteroids (0.8%, 95% CI: 0.4–1.1) were negligible in California and undetected in Texas. Adjusted screening rate before prescription for b/tsDMARDs in Arizona increased from 14.5% (95% CI 7.5–21.5) in 2012 to 26.7% (95% CI 17.6–35.8) in 2016. Rheumatologists prescribing b/tsDMARDs in Arizona screened more than other providers (20.9% [95% CI 13.9–27.9] vs 12.9% [95% CI 5.9–20.0]). Conclusion: Coccidioides serologic screening rates among Medicare beneficiaries with rheumatic/autoimmune diseases on b/tsDMARDs, csDMARDs, and noninhaled corticosteroids was low in Coccidioides spp.–US endemic regions between 2012 and 2016. Alignment of screening recommendations and clinical practice is needed.