Assessing blood pressure control in patients treated for hypertension: comparing different measurements and targets.

We examined how different methods and definitions of blood pressure affect the achievement of targets in general practice. There was a wide range in the proportion of treated patients achieving the different target levels recommended by the National Institute for Health and Clinical Excellence, British Hypertension Society and the general medical services contract. Among non-diabetic patients this ranged from; 10-37% (average office), 15-39% (standardised nurse measurement), 11-49% (last recorded) and 31-56% (ambulatory blood pressure). Defining targets without a clear definition of how blood pressure should be measured is largely meaningless and ignoring ambulatory blood pressure results in many patients being classified incorrectly as failing to achieve targets.