COST EFFICACY OF THE DIAGNOSIS AND THERAPY OF RENOVASCULAR HYPERTENSION

Numerous competing diagnostic modalities and the lack of data about th erapeutic benefit result in controversy concerning the identification and treatment of renovascular hypertension. Methods: Meta-analyses wer e used to examine the cost efficacy of renovascular hypertension diagn osis and treatment. Sensitivity, specificity and predictive value were calculated for captopril renography, Doppler, the captopril test and arteriography. Sensitivities and specificities were used to project co st per patient cured or improved for each modality, This was compared with the lifetime cost of medical therapy. Cost efficacy was calculate d using a hypothetical population (1000 patients, a prevalency rate of 30% for renal artery stenosis, expected cure or improvement rate of 0 .77 after angioplasty), Results: The sensitivity, specificity and posi tive predictive values were similar for all modalities except the capt opril test, which had a significantly lower sensitivity, The specifici ty was similar for all procedures; Doppler was highest but was mitigat ed by a 17% technical failure rate. The cost per patient cured or impr oved is greatest for arteriography and lowest for the captopril test. The relationship between cost per patient cured and the number of pati ents diagnosed in the population was calculated (relative value = (1/c ost) x number patients detected), The relative value of captopril reno graphy and arteriography is similar. Doppler and the captopril test ha ve the lowest relative value. If angioplasty reduces medication by thr ee drugs, the savings is $5807 to $8046 per patient. Surgical therapy is not cost-effective. Conclusion: Screening for renovascular hyperten sion is not cost-effective at a prevalence less than 30%, but captopri l renography is equally cost-effective as arteriography and obviates t he need for an arteriogram in many patients.