An evaluation of self-recorded blood pressure during drug trials.

Abstract

To our knowledge, there have been no published comparisons of different techniques for measuring blood pressure during clincal trials. We undertook a comparison during clincial trials with verapamil and prazosin. During an open trial of verapamil we compared the treatment-induced blood pressure reductions as measured by clinic, intra-arterial, and self-recorded methods. The mean reduction in blood pressure was 38 .+-. 13.6/20 .+-. 10.1 mm Hg for clinic blood pressure, 24 .+-. 17.9/16 .+-. 7.3 mm Hg for self-recorded blood pressure, and 23 .+-. 12.3/19 .+-. 10.1 mm Hg for mean daytime intra-arterial blood pressure. During prazosin treatment the mean reduction in blood pressure was 28 .+-. 21.5/18 .+-. 8.5 mm Hg for clinic blood pressure, 21 .+-. 20.5/6 .+-. 13.7 mm Hg for self-recorded blood pressure, and 18 .+-. 19.2/59.6 mm Hg for mean daytime intra-arterial blood pressure. There was little agreement between methods within individual patients and for group comparisons of intraarterial or clinic methods. There was, however, good agreement between intra-arterial and self-recorded methods. This study suggest that self-recorded blood pressure recording is suitable for monitoring efficacy of antihypertensive agents in a group of patients, although caution must be exercised when interpreting the effects of therapy when measured by indirect methods in an individual patient.