The incidence of venous thromboembolism: a prospective, community-based study in Perth, Western Australia.

OBJECTIVE: To determine the incidence of venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), in a well defined urban community broadly representative of the Australian population in terms of age, sex and ethnic distribution.

DESIGN, SETTING AND PARTICIPANTS: A prospective, community-based study conducted over a 13-month period from 1 October 2003 to 31 October 2004. People in a population of 151 923 permanent residents of north-eastern metropolitan Perth, Western Australia, who developed VTE during the study period were identified prospectively and retrospectively through multiple overlapping sources.

MAIN OUTCOME MEASURE: Number of cases of symptomatic, objectively verified DVT and PE.

RESULTS: 137 patients had 140 VTE events (87 DVT and 53 PE). The crude annual incidence per 1000 residents was 0.83 (95% CI, 0.69-0.97) for VTE, 0.52 (95% CI, 0.41-0.63) for DVT, and 0.31 (95% CI, 0.22-0.40) for PE. The annual incidence per 1000 residents after age adjustment to the World Health Organization World Standard Population was 0.57 (95% CI, 0.47-0.67) for VTE, 0.35 (95% CI, 0.26-0.44) for DVT, and 0.21 (95% CI, 0.14-0.28) for PE.

CONCLUSION: If the crude annual incidence of VTE in this area of metropolitan Perth is externally valid, then VTE affects about 17 000 Australians annually. Future studies of trends in VTE incidence will be needed to measure the effectiveness of VTE prevention strategies.