SCREENING FOR PERIPHERAL ARTERIAL-DISEASE - THE SENSITIVITY, SPECIFICITY, AND PREDICTIVE VALUE OF NONINVASIVE TESTS IN A DEFINED POPULATION

Large vessel peripheral arterial disease (LV-PAD) is a common conditio n that causes significant morbidity and disability. The authors evalua ted the individual components of a comprehensive noninvasive vascular examination to identify the most sensitive and specific measurements f or diagnosing LV-PAD. This cohort, initially screened between 1979 and 1981 in Rancho Bernardo, California, included 421 normal subjects and 63 subjects with LV-PAD. Segmental blood pressure ratios and flow vel ocities by Doppler ultrasound were used to define cases of LV-PAD. The sensitivity, specificity, positive predictive value, and negative pre dictive value of each individual component of the diagnostic algorithm were determined. Overall, measurements of posterior tibial flow showe d the highest sensitivity, specificity, positive predictive value, neg ative predictive value, and overall accuracy. In addition, an absent o r non-recordable posterior tibial peak forward flow, occurring in 96% of all limbs with isolated posterior tibial disease, or an ankle ratio less than or equal to 0.8 considered in parallel yielded a test with sensitivity of 89%, specificity of 99%, positive predictive value of 9 0%, negative predictive value of 99%, and overall accuracy of 98%. The se results indicate that the vast majority of LV-PAD cases can be dete cted with a single measurement using a handheld Doppler flowmeter empl oyed at the ankle.