Ambulatory blood pressure monitoring: measurement implications for research

Although blood pressure (BP) is a frequently used variable in nursing studies, measurements are likely to be inaccurate for a variety of reasons: incorrect technique, operator error, and environmental factors. Ambulatory BP monitoring (ABPM) reduces measurement error, is relatively easy to use, and yields many more BP parameters than do clinic BP measurements. The cost of equipment for ABPM ranges from $2,500 to $5,000 per monitor and from $2,000 to $3,000 for computer software. A research assistant can easily be trained to follow a standardized procedure. Researchers have used ABPM to study normal BP patterns, complications of hypertension, effects of antihypertensive drugs, and the prognosis of cardiovascular events. This article provides the nurse researcher with an introduction to this technology and an overview of information gained from ambulatory blood pressure monitoring.