A study of instruments in preparation for a blood pressure survey of children

In preparation for the measurement of blood pressure in children of a total geographic community, several preliminary studies of the validity and reliability of various methods and instruments for indirect blood pressure measurements were performed. These studies included Graeco-Latin Square designs, examination of children in a field setting, and assessments of the replicability of reading automatically recorded blood pressures. Each of the studies was designed to monitor the validity and replicability of instruments, methods, and observers. Controlling for subject, we compute biases due to instrument, method and observer and, where possible, eliminated them in the enusing studies. One automatic instrument, the Physiometrics recorder, was selected and used in conducting epidemiologic studies where it complements the measurements by the mercury sphygmomanometer.