In case-control study there weve 35 cases of lung cancer and 82 controls (without lung cancer). Among cases 33 had positive history of smoking and among controls 55 had positive history of smoking. Odds ratio in this study is -

Ans. is 'a' i.e., 8 o Odds ratio is cross product of entries in the table. o So, it is very impoant to make a correct table construct - i) History of exposure (risk factor) is arranged on left column (row). ii) Disease is arranged on the top ? a) Cases in middle column (row) b) Controls in right column (row)