Suppose 200 obese children and 500 normalweight children are

Suppose 200 obese children and 500. normal-weight children are identified in a school-based screening for hypertension. Eighteen of the obese children and 10 of the normal-weight children are hypertensive. What is the estimated risk of hypertension in each group? Provide an estimate of the risk difference and a 95% Cl about this estimate.

Solution

Risk difference = p1-p2 = 0.07

Pooled p = 28/700 = 0.04

Std error = square root of p1/n1+p2/n2

Std error for difference = 0.016395

Margin of error = 1.96(0.0164)

= 0.0321

Hence conf interval = 0.07-0.0321, 0.07+0.0321

=(0.379, 0.7321)

	Obese	Normal	Total
Children	200	500	700
Hypersensitive	18	10	28
Proportion(risk)	0.09	0.02