In a case control study on smoking and lung cancer, out of 35 lung cancer patients, 33 are smokers. Out of 82 controls, 27 are non smokers. Find the odds ratio:
High-Yield Explanation
Cancer Controls without cancer Smokers 33 (a) 55 (b) Non smokers 2 (c) 27 (d) Total 35 82 Odds ratio= axd/bxc = 33x27/55x2= 8.1 REMEMBER: while constructing table keep exposure in rows (e.g.: smokers v/s non smokers here) and presence or absence of disease condition in columns (e.g.: cancer v/s no cancer) Ref: Park's textbook of Preventive and Social Medicine, 21stedition, page-69.