Asymptomatic Peripheral Arterial Occlusive Disease Hooi et al. Incidence of and Risk Factors for Asymptomatic Peripheral Arterial Occlusive Disease: A Longitudinal Study

The current study describes the age- and sex-specific incidence rates and risk factors for asymptomatic and symptomatic peripheral arterial occlusive disease (PAOD) among 2,327 subjects and the incidence of intermittent claudication in asymptomatic PAOD subjects. The study population was selected from 18 general practice centers in the Netherlands. PAOD was assessed with the ankle-brachial blood pressure index, and intermittent claudication was assessed with a modified version of the Rose questionnaire. After 7.2 years, the overall incidence rate for asymptomatic PAOD, using the person-years method, was 9.9 (95 % confidence interval (CI): 7.3, 18.8) per 1,000 person-years at risk. The rate was 7.8 (95 % CI: 4.9, 20.3) for men and 12.4 (95 % CI: 7.7, 24.8) for women. For symptomatic PAOD, the incidence rate was 1.0 (95 % CI: 0.7, 7.5) overall, 0.4 (95 % CI: 0.3, 10.0) for men, and 1.8 (95 % CI: 1.0, 10.3) for women. Multivariate analyses showed that increasing age, smoking, hypertension, and diabetes mellitus were the most important risk factors. The overall incidence rate for intermittent claudication among PAOD subjects who were asymptomatic at baseline was 90.5 per 1,000 person-years at risk (95 % CI: 36.4, 378.3). The incidence of asymptomatic PAOD was higher than the incidence of symptomatic PAOD, with women developing PAOD more often than men. In the development of preventive strategies, modification of atherosclerotic risk factors, such as smoking, hypertension, and diabetes, should be the main goals. Am J Epidemiol 2001;153:666–72. arterial occlusive diseases; incidence; intermittent claudication; longitudinal studies; risk factors Received for publication July 6, 1998, and accepted for publica-tion March 23, 2000