In this article, we present a method for sample size calculation for studies involving both the intercept and slope parameters of a simple linear regression model. Some methods have been proposed in the literature to determine the adequate sample size. However, they are usually based on the line slope only. We propose a method based on the F statistic that involves both the intercept and the slope parameters of the model. The validation process is conducted by fitting a simple linear regression model and by testing a zero intercept and unity slope hypothesis. Compared to a traditional method and using Monte Carlo simulations, encouraging results attest for the clear superiority of the proposed method. The article ends with a real-life example showing the value of the new method in practice.
Colosimo, E. A., Cruz, F. R. B., Miranda, J. L. O., & Woensel, van, T. (2007). Sample size calculation for method validation using linear regression. Journal of Statistical Computation and Simulation, 77(6), 505-516. https://doi.org/10.1080/00949650601151729