|
Sample sizes to detect a significant difference in overall mortality. Numeric Results with Proportion Lost to Follow Up = 0.0200 |
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| Hazard Two-sided |
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|
|
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| Power |
N |
N1 |
N2 |
S1 |
S2 |
Ratio |
Alpha |
Beta |
|
|
||||||||
| 0.8002 |
1520 |
760 |
760 |
0.8200 |
0.8800 |
0.6442 |
0.0167 |
0.1998 |
| 0.8004 |
1089 |
545 |
544 |
0.8200 |
0.8900 |
0.5872 |
0.0167 |
0.1996 |
| 0.8003 |
2125 |
1063 |
1062 |
0.8300 |
0.8800 |
0.6861 |
0.0167 |
0.1997 |
| 0.8005 |
1437 |
719 |
718 |
0.8300 |
0.8900 |
0.6254 |
0.0167 |
0.1995 |
| 0.8001 |
3219 |
1610 |
1609 |
0.8400 |
0.8800 |
0.7332 |
0.0167 |
0.1999 |
| 0.8000 |
2002 |
1001 |
1001 |
0.8400 |
0.8900 |
0.6684 |
0.0167 |
0.2000 |
| 0.8001 |
5543 |
2772 |
2771 |
0.8500 |
0.8800 |
0.7866 |
0.0167 |
0.1999 |
| 0.8001 |
3025 |
1513 |
1512 |
0.8500 |
0.8900 |
0.7170 |
0.0167 |
0.1999 |
| 0.8000 |
12068 |
6034 |
6034 |
0.8600 |
0.8800 |
0.8476 |
0.0167 |
0.2000 |
| 0.8001 |
5194 |
2597 |
2597 |
0.8600 |
0.8900 |
0.7727 |
0.0167 |
0.1999 |
| 0.8000 |
46657 |
23329 |
23328 |
0.8700 |
0.8800 |
0.9179 |
0.0167 |
0.2000 |
| 0.8000 |
11271 |
5636 |
5635 |
0.8700 |
0.8900 |
0.8368 |
0.0167 |
0.2000 |
|
Summary Statements: A two-sided log rank test with an overall sample size of 2002 subjects (of which 1001 are in group 1 and 1001 are in group 2) achieves 80% power at a 0.0167 significance level to detect a difference of 0.0500 between 0.8400 and 0.8900 – the proportions surviving in groups 1 and 2, respectively. This corresponds to a hazard ratio of 0.6684. The proportion of patients lost during follow up was 0.0200. Software: PASS 2000, Power Analysis and Sample Size for Windows; NCSS, Kaysville, Utah | ||||||||
Raymond et al. Trials 2008 9:43 doi:10.1186/1745-6215-9-43 |
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