Effect of a public awareness campaign on the incidence of symptomatic objectively confirmed deep vein thrombosis: a controlled study


Bruce L Davidson, Division of Pulmonary and Critical Care Medicine, University of Washington School of Medicine, Seattle, WA, USA.
Tel.: +1 206 799 4513; fax: +1 815 550 2279
E-mail: brucedavidson@pobox.com


Summary.  Background:  Although there have been attempts to raise public awareness about deep vein thrombosis (DVT), their influence on identifying confirmed cases is unknown.

Objective:  To determine the effect and its duration of a public awareness campaign about venous thromboembolism.

Patients/Methods:  A campaign to raise public awareness of DVT was conducted during one year in an urban population of approximately 100 000 (pop A). A comparison urban population of approximately 1 574 000 (pop B) was not exposed to this campaign. Patients symptomatic for DVT in both populations were referred by general practitioners for a standardized compression ultrasound (CUS) of the whole leg at no charge. Positive CUS examinations documented by photographs were analyzed by an independent adjudication committee blinded to the population. Pop A was followed for 8 months after the information campaign ended.

Results and Conclusions:  Symptomatic objectively confirmed DVT was found in 48 of 800 subjects tested in pop A and 226 of 2384 tested in pop B. The 1-year incidence of confirmed DVT (proximal and distal) was 46/100 000 (95% CI, 33–59) in A and 14/100 000 (95% CI, 12–16) in B (P < 0.001). The increase in pop A was due to distal DVT (36/100 000 vs. 5/100 000 in pop B, P < 0.001). The DVT rate for pop A in an 8-month follow-up period was 12/100 000, significantly lower than in the first 8 months of the study period (34/100 000/8 months) (P = 0.001). The public awareness campaign significantly increased the diagnosis of distal DVT. When the campaign ended, DVT rates returned to community baseline.