Total sample size required to determine whether a correlation coefficient differs from zero.
Instructions: Enter parameters in the red cells. The answer will appear in blue below.
The standard normal deviate for α = Zα =
The standard normal deviate for β = Zβ =
C = 0.5 * ln[(1+r)/(1-r)] =
Total sample size = N = [(Zα+Zβ)/C]2 + 3 =
Reference: Hulley SB, Cummings SR, Browner WS, Grady D, Newman TB. Designing clinical research : an epidemiologic approach. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013. Appendix 6C, page 79.