Mean in population 1 | Mean in population 2 | % difference^{b} | Required sample size^{c} | ||
---|---|---|---|---|---|
No measurement error^{d} | With measurement error^{e} | ||||
Total estradiol (ng/dl) | |||||
1500 | 1725 | 15 | 154 | 193 | |
1500 | 1800 | 20 | 91 | 113 | |
1500 | 1875 | 25 | 60 | 76 | |
SHBG (nmol/l) | |||||
44 | 50.6 | 15 | 84 | 87 | |
44 | 52.8 | 20 | 50 | 51 | |
44 | 55.0 | 25 | 33 | 34 |
^{a} Three sets of hypothetical means are set such that the true means in population 2 are 15, 20, and 25% higher than the true means in population 1, respectively.
^{b} 100 × [(mean in population 2) − (mean in population 1)]/(mean in population 1).
^{c} Sample size for each population (equal sample size) was calculated for α = 0.05 (two-sided) and 80% power.
^{d} Variances used for total estradiol and SHBG were 0.0362 and 0.0198, respectively, based on data on the logarithmic scale (base 10).
^{e} Variances used for total estradiol and SHBG were 0.0453 and 0.0204, respectively, based on data on the logarithmic scale (base 10).