Table 1.

Hypothetical example illustrating the association between drinking alcohol at the conference reception and suffering from jet lag the next day before and after stratification for whether the delegate attended the plenary session

Delegate ClassificationJet Lag
YesNo
A
 Drank alcohol at reception
  Yes100100
  No150150
B
 Delegate missed plenary session
  Drank alcohol at reception
   Yes8060
   No10030
 Delegate attended plenary session
  Drank alcohol at reception
   Yes2040
   No50120
  • Odds ratio for A is Embedded Image Mantel–Haenszel odds ratio for B is Embedded Image.