Table A2.2

‚ÄÉNumber of female and male chlamydia cases needed according to desired odds ratio and study power

WomenMen
No of casesDetectable odds ratioNo of casesDetectable odds ratio
PowerPower
Calculations based on a two sided significance level of 0.05 in univariate analysis ignoring matching. Frequency of exposure in controls 20%.
80%90%95%80%90%95%
1701.892.062.201142.162.392.59
2201.751.892.001461.982.182.33
2801.651.761.861971.811.962.06