Secular Trends in Incidence and Mortality of Acute Venous Thromboembolism: The AB-VTE Population-Based Study

Abstract

BackgroundVenous thromboembolism is a major cause of morbidity and mortality, and comprehensive studies profiling the epidemiology and pattern of health services use are needed. In this study we provide contemporary estimates of venous thromboembolism incidence and case fatality over the past decade. MethodsWe developed a population-based venous thromboembolism dataset by linking 6 administrative health databases in Alberta, Canada from April 1, 2002 to March 31, 2012. We defined acute symptomatic cases using a validated algorithm and used Poisson regression to model annual venous thromboembolism counts. ResultsWe identified 31,656 cases of acute symptomatic venous thromboembolism between April 1, 2002 and March 31, 2012. The age- and sex-adjusted incidence rate of venous thromboembolism was 1.38 (95% confidence interval [CI], 1.37-1.40) per 1000 person-years. For pulmonary embolism it was 0.38 (95% CI, 0.36-0.40) per 1000 person-years, and for deep vein thrombosis it was 1.0 (95% CI, 0.99-1.1) per 1000 person-years. The adjusted model showed no significant change in the incidence of venous thromboembolism during the study period. The 30-day case fatality rate of venous thromboembolism was 2.0% (95% CI, 1.89-2.21) and was almost doubled in patients with pulmonary embolism: 3.9% (95% CI, 3.50-4.33). The 1-year case fatality rate was 9.2% (95% CI, 8.88-9.52) for venous thromboembolism and 12.9% (95% CI, 12.2-13.6) for patients with pulmonary embolism. The case fatality rate increased with increasing subject age. The 1-year and 5-year survivals after first acute venous thromboembolism were similar in patients with unprovoked and provoked events. However, in patients with cancer-associated thrombosis, the 1-year and 5-year survival rate was 66% (95% CI, 64.71%-67.29%) and 46% (95% CI, 43.28%-48.72%), respectively. ConclusionThe incidence of acute venous thromboembolism remained unchanged over a 10-year period. However, the case fatality of venous thromboembolism is substantial.