Sample Size Determination
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Evaluation of a Diagnostic Test
This utility can be used to calculate required sample size when you want to evaluate performance of a diagnostic test and want to estimate it's 'sensitivity' and 'specificity' with specified preecision.
Formula used and other details
Your guesstimate of Sensitivity of the test %
Enter number between 0.01 to 99.99
Required
Approxiate estimate of sensitivity (in percentage) based on previous studies / pilot studies etc. Should be between 0.01 to 99.99
Confidence Level % (for sensitivity)
Enter number between 1 to 99
Required
In percentage. Commonly used values are 95, 99 and 90. Should be between 0.01 to 99.99.
Allowable error % in Sensitivity
Enter number between 0.01 to 99.99
Required
Absolute
Relative
Allowable error in percentage on both sides of Sensitivity. Should be between 0.01 to 99.99.
Your guesstimate of Specificity of the test %
Enter number between 0.01 to 99.99
Required
Approxiate estimate of specificity (in percentage) based on previous studies / pilot studies etc. Should be between 0.01 to 99.99
Confidence Level % (for specificity)
Enter positive 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 % in Specificity
Enter number between 0.01 to 99.99
Required
Absolute
Relative
Allowable error in percentage on both sides of Specificity. Should be between 0.01 to 99.99.
Prevalence of the disease (in Percentage)
Enter number between 0.01 to 99.99
Required
Approximate Proportion of diseased in population, (in your setting). Should be between 0.01 to 99.99.
Sample Size Required =