WHEN TO MEASURE RESTING VALUES IN STUDIES OF CHILDRENS CARDIOVASCULARREACTIVITY

Investigations suggesting that the order of obtaining resting and card iovascular reactivity measurements moderates values have provided inco nsistent results and have not analyzed data from children; the general izability of results is uncertain. In this investigation, all children enrolled in the eighth-grade classrooms of the public schools of an e ntire county (n = 451) participated in standardized reactivity assessm ents. The order of resting and reactivity measurements was randomized by examination day (a total of 19 days). Analyses indicated that all c omparisons of order effects on mean resting blood pressure and heart r ate, as well as reactivity (both change from resting and absolute valu es and both mean and maximal values), were nonsignificant. Results ind icate that measurement order is not always a necessary consideration i n studies of reactivity; the conditions under which measurement order is a consideration requires clarification.