Question 20

Question:

A retrospective study is conducted on Gulf War veterans to determine the risk factors contributing to Gulf War syndrome. What statistical tool would be best to determine the most significant contributor?

Correct Answer: C.  Odds ratio

An odds ratio analysis would be the best tool because it is preferred for case-control and retrospective studies. An odds ratio is defined as the odds of an event (in this case, a particular risk factor) occuring in an ‘affected’ group (those with Gulf War syndrome) over over the odds of that event occuring in an unaffected group (those who did not develop Gulf War syndrome). Relative risk is generally employed in cohort studies and randomized controlled trials. Anova analyses and paired sample t-test require paired samples (not the case here).