Measurement of Blood Pressure Systolic Blood Pressure Differences Among Pediatric Epidemiological Studies

This report reviews the results of six large blood pressure surreys done on pediatric populations and points out factors responsible for differences in the blood pressure norms. Tbe studies were selected on the basis of there being recent examinations of large numbers of children. Important differences in mean systolic pressures and 95th percentile rallies were found among the studies, which may be attributed to: 1) actual differences among the populations; 2) biases due to methodological differences; or 3) increased sampling variability with small sample sizes. Actual differences in pressures among tbe populations surreyed may be due to differences in geographic location, radal composition, or average body sizes. Discrepancies due to methodological biases'may have occurred because of associated venlpuncture or exercise stress on the day of the examination; differences in selection of blood pressure cuff sizes; differences in the number of measurements averaged. In several studies, small sample sizes for each age-race-sex subclass accounted for considerable variability of the 95th percentile value. Tbe implication of this analysis is that before the 95th percentile norms for children of different ages, races, and sexes can be more firmly established, it is necessary to collect larger sample sizes controlling for known biasing factors and using a standardized methodology. (Hypertension 2 (suppl I): I-3-I-7, 1980)