Comparison of Power Estimation of Unmatched Case Control study to other public software programs.

Date last tested: 7/11/05.

| CI%, n1, p1, n2, p2
Data input | 95%, 100, 20%, 200, 10%1 | 95%, 100, 10%, 200, 20% | 95, 474, 45%, 255, 35.29% | 95, 474, 35.29%, 255, 45%
software | Power | Power with continuity correction | Power | Power with continuity correction | Power | Power with continuity correction | Power | Power with continuity correction
OpenEpi | 65.78% | 59.26% | 60.09% | 52.65% | 72.12% | 69.32% | 72.67% | 69.93%
PEPI | 65.78% | 59.25% | 60.09% | 52.5% | 72.12% | 69.32 | 72.66% | 69.93%
EPI 505 | 65.8% | NA | 60.08% | NA | 72.03% | NA | 72.58% | NA

Confidence interval CI; number of cases ‘n1’; percent of exposure among cases ‘p1’; number of controls ‘n2’; percent of exposure among controls ‘p2’.

Reference:

· PEPI: Abramson JH and Gahlinger PM (2001). Computer program for epidemiologists: PEPI version 4.0. Sagebrush Press, Salt Lake City. Used POWR.EXE version 4.0.

· Epidemiology 505 - Emory University (version - 11 October 2000)