Table 2 Simulated preliminary data for power and sample size calculations
From: Sample size and power determination when limited preliminary information is available
Variable | Estimated correlation coefficient | ||||||
|---|---|---|---|---|---|---|---|
0.50 | 0.80 | 0.90 | |||||
N | Mean | STDa | Mean | STDa | Mean | STDa | |
The simulated MRI breast density at baseline data | 10,000 | 22.1 | 2.59 | 22.1 | 2.59 | 22.1 | 2.59 |
The simulated MRI breast density at follow-up data | 10,000 | 16.3 | 3.33 | 16.3 | 3.32 | 16.3 | 3.32 |
pre_ctH2O: Predicted mean and STD for 2nd simulation | 5,000,000 | 23.8 | 1.53 | 23.8 | 1.53 | 23.8 | 1.53 |
post_ctH2O: Predicted mean and STD for 2nd simulation | 5,000,000 | 21.3 | 1.64 | 21.3 | 1.64 | 21.4 | 1.63 |
Random selected baseline water data after applying the regression model | 5,000,000 | 23.9 | 2.16 | 23.9 | 2.16 | 23.9 | 2.16 |
Random selected follow-up water data after applying the regression model | 5,000,000 | 21.3 | 2.32 | 21.3 | 2.32 | 21.4 | 2.31 |
Water: Follow-up data – Baseline data b | 5,000,000 | -2.5 | 2.12 | −2.5 | 1.42 | −2.5 | 1.09 |
pre_ctHHb: Predicted mean and STD for 2nd simulation | 5,000,000 | 5.2 | 0.19 | 5.2 | 0.19 | 5.2 | 0.19 |
post_ctHHb: Predicted mean and STD for 2nd simulation | 5,000,000 | 4.8 | 0.23 | 4.8 | 0.23 | 4.9 | 0.23 |
Random selected baseline ctHHb data after applying the regression model | 5,000,000 | 5.2 | 0.26 | 5.2 | 0.26 | 5.2 | 0.26 |
Random selected follow-up ctHHb data after applying the regression model | 5,000,000 | 4.8 | 0.32 | 4.9 | 0.32 | 4.9 | 0.32 |
ctHHb: Follow-up data – Baseline data b | 5,000,000 | −0.3 | 0.29 | −0.3 | 0.20 | −0.3 | 0.16 |
pre_Lipid: Predicted mean and STD for 2nd simulation | 5,000,000 | 66.3 | 2.06 | 66.3 | 2.06 | 66.3 | 2.06 |
post_Lipid: Predicted mean and STD for 2nd simulation | 5,000,000 | 68.9 | 2.01 | 68.9 | 2.00 | 68.9 | 2.00 |
Random selected baseline Lipid data after applying the regression model | 5,000,000 | 66.3 | 2.92 | 66.3 | 2.92 | 66.3 | 2.92 |
Random selected follow-up Lipid data after applying the regression model | 5,000,000 | 68.9 | 2.84 | 68.9 | 2.84 | 68.9 | 2.83 |
Lipid: Follow-up data – Baseline data b | 5,000,000 | 2.6 | 2.63 | 2.6 | 1.82 | 2.6 | 1.44 |