Sample Size Determination
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Estimation of Relative Risk with specified precision.
This utility can be used to calculate required sample size when your objective is to estimate Relative Risk with a specified precision.
Formula used and other details
Confidence Level %
Enter number between 0.01 to 99.99
Required
In percentage. Commonly used values are 95, 99 and 90. Should be between 0.01 to 99.99.
Allowable error or Precision
Enter positive number between 0.01 and 99.99
Required
Margin of error towards both sides of Actual Relative Risk (In percentage).
Control (non-exposed): Cohort (exposed) Ratio
Enter integer from 0.01 to 9.00
Required
Ratio of Participants in Cohort Group to Control (non-exposed) Group
Select any two of these three
Relative Risk
Incidence Rate amongst exposed
Incidence Rate among non-exposed
Sample Size Required =