Question 1: Exposure Information Validation (15 points)

An epidemiologist was interested in comparing data provided by mothers about their smoking status during pregnancy on their child's birth certificate with data on smoking status recorded in their medical record (This is a real study conducted in 1993, name of the author withheld). For this study, we will consider the medical record as the gold standard and the birth certificate to be the imperfect classification scheme. The result is shown in the table below:

		Medical Record
		Smoker	Non-Smoker	Total
Birth Certificate	Smoker	128	5	133
Non-Smoker	36	465	501
	Total	164	470	634

1. Using the data from this table, compute the sensitivity and specificity of smoking status as reported on the birth certificate. (5 points).
2. What are your observations concerning the true smokers and the true non-smokers? (5 points)
3. What feasible methods would you employ to reduce the misclassification of exposure among the true smokers? (5 points)