A Simple Formula For Sample Size Calculation In Equivalence Studies. N A κ n B and n B p A 1 p A κ p B 1 p B z 1 α z 1 β 2 p A p B δ 2. In this paper we propose a simple formula for sample size calculation based on central t -distribution.
Sample size estimation in clinical research. Za2 pq where the symbol means to the power of. The sample size is then determined from the power function either by numerical method or closed formulas.
Raw or log-transformed the formulas.
The standard and novel treatments is less than or equal to D indicating equivalence. Expected population standard deviation SD SD. The proposed formula has better properties than those currently available and it can be easily applied in all equivalence studies. Using the assurance concept values of the standard deviation for the distribution of potential logTRratios can be chosen to reflect the magnitude of uncertainty.
