Abstract:Although inaccurate, non-reproducible blood pressure values can result from non-standardized assessments, recommended approaches to standardize blood pressure measurement are often not followed in research studies.An expert consensus of national and international health and scientific organizations developed recommended minimum standards for assessing blood pressure in research subjects where: 1) blood pressure or hypertension is a major endpoint, or 2) blood pressure is likely a major mediator of the research outcome. Minimum research standards are presented for training of observers, technical aspects of assessing blood pressure, and equipment for both adults and children. The standards are based on prior recommendations some of which did not conform to current evidence based methods. All new research should require adherence to these minimum standards on the patient populations described above. Readers need to use caution in interpreting studies if the standards are not met in the defined populations.
Recommendations TrainingThe number of observers and the professional background of the observer(s) are indicated (e.g.physician, community health workers, nurse, or research assistant).Those who directly assess blood pressure or those who train or teach subjects in blood pressure measurement protocols must be specifically trained for the blood pressure measurement as part of the quality control for the research study. This applies to office, home/self, and ambulatory blood pressure assessments. There is semi-annual competency testing of those who directly assess blood pressure or those who train or teach subjects in blood pressure measurement protocols when indicated in studies of a longer duration.The observers need to be evaluated, and quality of performance needs to be periodically assessed using statistical tables to detect bias in recorded measurements. Technician retraining is necessary where deficiencies are found.
Technical AspectsThe measurement conditions are indicated (e.g.location, position/posture, resting period, or instructions provided for home/self or ambulatory measurement).All aspects of patient preparation and blood pressure measurement must conform with the published guidelines of a national or international body recognized for its work in blood pressure measurement [1, 2, 4-6, 21, 22]. The specific set of technical recommendations used in the study must be referenced and all modifications to the recommended techniques and procedures disclosed.The blood pressure measurement protocol is provided in sufficient detail so that it can be duplicated precisely by others (e.g. number of readings recorded, time intervals between readings, criteria for discarding readings, and number of readings to make the estimation).
Blood Pressure DevicesAll manual devices must be assessed for calibration at the start, every 6 months, and end of the study, and the data are to be assessed and reported for terminal digit preference. References are provided for protocols verifying calibration of manual de...