Assumption | Size | ||
---|---|---|---|
Two-sided confidence level (1−α) | 95 | ||
Power (% chance of detecting) | 80 | ||
Ratio of controls to cases | 2 | ||
Hypothetical proportion of controls with exposure | 40 | ||
Hypothetical proportion of cases with exposure | 53.13 | ||
Least extreme OR to be detected | 1.70 | ||
Kelsey | Fleiss | Fleiss (with continuity correction) | |
Sample size for cases | 169 | 169 | 180 |
Sample size for controls | 338 | 338 | 360 |
Total sample size | 507 | 507 | 540 |
Note: a slightly larger sample size (total of 570 cases and controls) was recruited.