Module 2.2 Unit 5 Assignment 6

Stratified analysis

[Total marks =25]

Assignment

Suppose a investigators wanted to study the relationship between alcohol drinking and liver cancer, had the following results

Alcohol	Liver cancer	Controls
Yes	30	18
No	70	82
Total	100	100

a. Calculate and interpret the measure of association for this study (3)

Suppose the investigators, wanted to investigate whether age was confounding the relationship between alcohol drinking and liver cancer, and the results are presented below:

Age (y)	Liver cancer	Controls
<40	50	80
>40	50	20
Total	100	100

b. Calculate the relationship of age and liver cancer (3)

c. What is the relationship between age and alcohol, given the results below (3)

Age (y)	Total	Alcohol	No Alcohol	% Exposed
<40	130	13	117	10
>40	70	35	35	50

Stratification by age yields the following results

Age (y)	Exposed	Cases	Controls		Odds Ratio
<40	Yes	5	8	}
	No	45	72
	Total	50	80
>40	Yes	25	10	}
	No	25	10
	Total	50	20

d. Calculate the odds ratio of the relationship between alcohol drinking and liver cancer after stratifying by age ieCalculate the summary MH_OR of developing dental caries across age groups (5)

e. Interpret your findings; a through d. (6)