Coronavirus disease 2019 (Covid-19) is now a leading cause of death among U.S. adults. In addition to profound respiratory and multi-organ failure, hypercoagulable states and venous thromboembolism (VTE) have been increasingly reported in patients with severe Covid-19. The aim of this study is evaluate the risk of VTE related to Covid-19 infection in a real-world community-based population.

This is an observational study of adult (age ≥18 years) members enrolled in the Kaiser Permanente Northern California (KPNC) or Kaiser Permanente Southern California (KPSC) integrated healthcare delivery systems during the time period January 1, 2020 through January 31, 2021, (representing the first year of the Covid-19 pandemic) and diagnosed with incident Covid-19. The outcomes will be incident VTE and all-cause death, assessed through February 28, 2021. The primary analysis will describe the rate of post-Covid-19 VTE after index diagnosis. A second analysis will compare the risk of VTE in hospitalized patients with Covid-19 compared with matched hospitalized controls without Covid-19.

Inclusion

• Covid-19 diagnosis (defined as date of a positive laboratory test for SARS-CoV-2 virus) during the time period January 1, 2020 to January 31, 2021
• Age >=18 years
• Continuous pharmacy benefits and health plan membership for at least 12 months before the index date

Exclusion

• incomplete information on age and sex

The source populations for the study will be adults diagnosed with acute Covid-19 who were enrolled in Kaiser Permanente Northern California or Kaiser Permanente Southern California, two large, integrated healthcare delivery systems in California.