Sample size calculator - Risk Calc
riskcalc.org › samplesizeSample size estimation in clinical research: from randomized controlled trials to observational studies. Chest, 158(1), pp.S12-S20. Wang, X. and Ji, X., 2020. Sample size formulas for different study designs: supplement document for sample size estimation in clinical research.
Sample size calculator - Risk Calc
https://riskcalc.org/samplesizeSample Size Calculator Sample Size Estimation in Clinical Research: ... One case will be matched to one control (i.e., \(k = 1\))and the correlation between case and control exposures for matched pairs is estimated to be 0.01 (low, i.e., \(r = 0.01\)). It is assumed that 20% of controls will be smokers or past smokers ...
Sample Size Estimation - Correlation
www2.ccrb.cuhk.edu.hk › stat › otherGiven a sample correlation rbased on Nobservations that is distributed about an actual correlation value (parameter) ρ, thenis normally distributed with meanand variance. Under the null hypothesis, the test statistic iswhere The sample size to achieve specified significance level and power is