Question

		Outcome
Exposure		Asthma	No Asthma	Total
	Smoker in the household	418	1003	1421
	No smoker in the household	352	1235	1587
	Total	770	2238	3008

A cross-sectional study examined children between the ages of 1 and 17 to determine the prevalence of asthma and of indoor environmental risk factors for childhood asthma. Data was collected by questionnaires, which were completed by each child's primary caretaker. Having a smoker in the household was found to be a significant risk factor for childhood asthma. The following 2X2 table illustrates the study findings related to this risk factor.

1. Calculate the prevalence ratio or prevalence rate ratio (PR) for having a smoker in the household (Hint: exposure!). Keep 5 decimal places for intermediate steps and report your final answer rounded to two decimal places. Interpret the resulting PR calculated.

Answer 1