LAUSR

Patients with polycythemia vera (PV) and essential thrombocythemia (ET) have increased thrombotic risk. This retrospective, real-world analysis of Medicare patients (age ≥ 65 years) newly diagnosed with high-risk PV or intermediate-/high-risk ET compared mortality risk among those with versus without thrombotic events during the study period. Patients diagnosed with PV or ET with ≥ 1 inpatient or ≥ 2 outpatient claims (January 1, 2010-December 31, 2017; index was date of first qualifying claim) were included. The study included 50,405 Medicare beneficiaries with PV and 124,569 with ET. During follow-up (median [range]: PV, 34.5 [0-97.3] months; ET, 25.5 [0-97.4] months), 14,334 patients (28.4%) with PV and 30,478 (24.5%) with ET experienced thrombotic events (most commonly ischemic stroke [PV, 46.0%; ET, 42.5%]. Mortality risk was increased for patients with versus without post-index thrombosis for both PV (adjusted hazard ratio [aHR; 95% CI], 18.6 [16.1-21.6]; P < 0.001) and ET (aHR [95% CI], 25.2 [23.1-27.5]; P < 0.001). Median survival was shorter for patients who experienced a thrombotic event ≤ 1 year post-index versus those who did not (PV, 5.1 years vs not reached; ET, 3.7 vs 6.7 years; both P < 0.001). These findings highlight the importance of thrombosis risk mitigation in PV and ET management.