Cost effectiveness of clinical diagnosis, venography, and noninvasive testing in patients with symptomatic deep-vein thrombosis.

Until the past decade, physicians were content to base therapeutic decisions on the clinical diagnosis of deep-vein thrombosis. Subsequently, numerous studies demonstrated that clinical diagnosis of this condition is nonspecific. Although many now use objective methods to diagnose venous thrombosis, their relative cost and effectiveness have not been adequately studied. We performed a cost-effectiveness analysis of 516 patients with clinically suspected venous thrombosis who were evaluated by clinical diagnosis, venography, and the less invasive combination of impedance plethysmography and leg scanning. We used this analysis to rank these alternative approaches in terms of both cost and effectiveness. The results indicate that clinical diagnosis is cost ineffective. Venography is cost effective--more so when applied as an outpatient investigation. Impedance plethysmography plus leg scanning is a practical, less invasive alternative to outpatient venography. The cost of inpatient diagnosis is likely to remain the major cost; thus, emphasis should be placed on outpatient diagnostic procedures.