Question 3

A case-control study was undertaken by Ward et al. 2002 to investigate the association between Creutzfeldt-Jakob disease (CJD) and previous surgery. A group of 322 patients with CJD and a group of 325 patients without CJD were asked whether they had undergone any surgery in the past year. Of the patients with CJD, 260 had undergone surgery in the past years compared with 230 patients without CJD.

a) Draw a 2 by 2 table

b) Analyse these data and write a summary report concluding your findings

c) Comment briefly on why the measure of effect you chose is appropriate for the study.