Observer Factors in the Measurement of Blood Pressure

NURSES TODAY assist in many clinical research projects, both by giving care to patients and by making measurements and other observations which are part of the data collected in the research. At the Clinical Center for Medical Research of the National Institutes of Health in Bethesda, Md., the Nursing Department makes a special effort to insure that the data collected by nurses are valid and reliable. This is a report of an investigation of a measurement frequently made by nurses when assisting in clinical research, namely, the measurement of blood pressure. In the clinical determination of blood pressure, errors of measurement arise from the limitations of the sphygmomanometer, from the inherent variability of human arterial blood pressure, and from interobserver differences. It was decided to study specifically the contribution of the nurseobserver. The aim was to answer the question, "How much alike do nurses measure blood pressure?" and to study