INCIDENCE OF VENOUS THROMBOTIC EVENTS AND EVENTS OF SPECIAL INTEREST IN A RETROSPECTIVE COHORT OF COMMERCIALLY-INSURED US PATIENTS

ObjectiveTo estimate the US incidence of thrombotic events and related rare diagnoses.DesignClaims-based retrospective cohort study of incidence.SettingUS commercial health insurance administrative claims database.ParticipantsAdults 25-65 years of age between 2015 and 2019 with a minimum of 12 consecutive thrombosis-free months of continuous enrollment beginning 2014 were selected.Main OutcomesAge (10-year intervals) and sex stratum specific incidence rates per 100,000 person-years were determined for: venous thromboembolism (VTE), cerebral venous thrombosis (CVT), and other major venous thrombotic events, and events of special interest, including immune thrombocytopenic purpura (ITP), hemolytic-uremic syndrome (HUS), and heparin-induced thrombocytopenia (HIT).ResultsOf 13,249,229 enrollees (half female/male), incidence of venous thromboembolic events (DVT, PE, CVT, or other major venous thrombotic conditions) was 247.89 per 100,000 person-years (95% CI: 245.96, 249.84). Incidence of VTE was 213.79 with ICD codes alone (95% CI: 211.99, 215.59) and 127.18 (95% CI: 125.80, 128.58) when also requiring a filled anticoagulation prescription. Incidence was 6.37 for CVT (95% CI: 6.07, 6.69), 26.06 for ITP (95% CI: 25.44, 26.78), 0.94 for HUS (95% CI: 0.82, 1.06), and 4.82 for HIT (95% CI: 4.56, 5.10). The co-occurrence of CVT with either ITP or HIT (diagnoses within 14 days of one another) was 0.090 (95% CI: 0.06, 0.13). Incidence tended to increase with age and was higher for women under 55. Incidence for CVT, HUS, and CVT with ITP or HIT was higher for women in all age groups. Incidence of PE and CVT increased significantly over the five-year period, while DVT rates decreased.ConclusionsThese results are the first US estimates for incidence of thrombotic and rare events of interest in a large, commercially-insured US population. Findings provide a critically important reference for determining excess morbidity associated with COVID-19 and more generally for vaccine pharmacovigilance.BOX POINTSWhat is already known on this topic?Incidence of venous thromboembolic diagnoses vary by country and date.There have been improvements in the past decade in thromboprophylaxis (e.g., for deep vein thrombosis) and detection (e.g., for cerebral venous thrombosis), but there are no recent comprehensive estimates for the United States.What this study addsOur results document the US incidence of thrombotic and related rare diagnoses for the most recent five-year pre-pandemic period (2015-2019) in an insured population.