Question

1. Consider the following outcome from a hospital study on seatbelt use and ER visits by sex.

Seatbelt Use	Males		Females
	ER visit Yes	ER Visit No	ER visit Yes	ER Visit No	Total
Yes	23,110	288,082	30,837	200,337	542,366
No	6,211	18851	6,030	10,304	41,396
Total	29,321	306,933	36,867	210,641	583,762

a)      Calculate the Crude Odds ratio of the relationship between seatbelt use and ER visit. [4]

b)      Calculate the odds ratio of the association between seatbelt use and ER visit in males [4]

c)       Calculate the odds ratio of the association between seatbelt use and ER visit in females [4]

d)      Is sex a confounder, effect measure modifier or neither? [4]

Answer 1

Gie tot tne Epusl ERvISH ACD yes За 837 6, 030 36. 867 yes 오3,1㎞ 289.081 621 1295 210,6ul Tab 29.31 2o6 933 uhese eニ numbes of "uheposed cases (Ct) Ca) )odds catio of the relationshup betowen seattalt cse and ER uisH 113083)13a) + rou) (288081 200333) (6211 + 6030) OR ods alio o e calislt ise and ion betoeen Seutbol uisit in maley C13llo x 188s 29908ㄵ 6211) OR: a Ssotiolian uisit in fesale OR 20033 6030 0263