Hypertension Intervention Pooling Project.

Data from 12 independently designed and conducted randomized trials of behavioral interventions for hypertension, consisting principally of variants of relaxation and biofeedback therapies, were aggregated to assess current progress of research in this area. Meta-analytical methods revealed a statistically significant decrease in diastolic blood pressure for nonmedicated patients at the end of intervention. No significant improvement was detected in medicated patients, but potential differential effectiveness of prescribed medications and differences in compliance among patients prohibits separation of changes due to behavioral treatments alone. The need to devise criteria for selection of patients, and to establish the most appropriate patient-treatment match is emphasized.