Prevelans çalışmasınalizi
Power analysis for correlation analysis
If you are investigating the correlation between two numerical variables , you can estimate the minimum number of participants required for a correlation coefficient you have determined from the literature to be statistically significant.
Required information
α error: : Indicates the significance level of the p value. Select between 0.05 and 0.01.
Strength (1-β): Select between 80% and 90% for targeted strength
Correlation coefficient: Enter a correlation value in the range of 0-1.
Sample calculation: To calculate the minimum number of patients required for a correlation expectation of r=0.5 (medium) between two numerical variables to be found statistically significant at the 0.05 level and with 80% power, the information should be entered into the application as follows.
After checking Calculate, you can reach the minimum number of patients required. This field can be copied.
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.