Free research tools · Page 6

Paired Change SD Calculator

Recover the SD of within-person change from marginal SDs and an explicit correlation.

Explore the equal-cluster design effect and approximate information-equivalent sample size.

Calculate descriptive Bland–Altman limits from the mean and SD of paired measurement differences.

Explore how a specified likelihood ratio changes a hypothetical pretest probability.

Find arithmetic discrepancies across screening, allocation, intervention receipt and analysis counts.

Predict row multiplication and unmatched output before an equality join using aggregate key counts.

Calculate an unadjusted risk ratio and approximate log-Wald interval from two independent groups.

Check sensitivity, specificity, and predictive-value denominators using aggregate test counts.

Standardize an independent-group mean difference using a pooled SD and approximate small-sample correction.

Recover a normal-approximation SE on a difference or log-ratio scale from compatible interval limits.

Apply Holm or Benjamini–Hochberg adjustments to a complete family of exact p-values.

Calculate a descriptive event rate with an explicit person-time denominator and reporting unit.