Sphygmomanometer calibration--why, how and how often?

BACKGROUND: Hypertension is the most commonly managed problem in general practice. Systematic errors in blood pressure measurements caused by inadequate sphygmomanometer calibration are a common cause of over- and underidentification of hypertension. OBJECTIVE: This article reviews sphygmomanometer error and makes recommendations regarding in service maintenance and calibration of sphygmomanometers. DISCUSSION: Most sphygmomanometer surveys report high rates of inadequate calibration and other faults, particularly in aneroid sphygmomanometers. Automatic electronic sphygmomanometers produce systematic errors in some patients. All sphygmomanometers should be checked and calibrated by an accredited laboratory at least annually. Aneroid sphygmomanometers should be calibrated every 6 months. Only properly validated automatic sphygmomanometers should be used. Practices should perform regular in house checks of sphygmomanometers. Good sphygmomanometer maintenance and traceable sphygmomanometer calibration will contribute to reducing the burden of cardiovascular disease and the number of patients overtreated for hypertension in Australia. (author abstract)