Telemedicine improves diagnosis of essential hypertension compared with usual care.

A randomized controlled trial was conducted to assess the efficacy of a telemedicine service for the diagnosis of essential hypertension. The telemedicine service consisted of using an automatic home blood pressure monitor connected to an ordinary telephone line for the transmission of the data to a central computer. After use of the home monitor for a week, the results were converted to a report form and faxed to the patient's physician. The gold standard for assessment of true hypertension status was 24 h ambulatory blood pressure monitoring. A total of 74 patients from outpatient clinics were randomized into either the telemedicine service or usual care. Use of the telemedicine service significantly improved the detection of essential hypertension compared with usual care: in the telemedicine group, 64% of patients with essential hypertension were diagnosed; in the usual care group, 26% of patients with essential hypertension were diagnosed. Furthermore, diagnosis occurred earlier in the telemedicine group than in patients receiving usual care. Specificity and positive predictive value were similar in the two groups.