Calculate Cochran’s Q, I² with its confidence interval, H², τ² and fixed and random-effects pooled estimates from study effects and standard errors.
About this tool
Cochran's Q, I², H², τ² and pooled estimates for a meta-analysis.
How to use I² Heterogeneity Calculator
- Paste one study per line as effect, standard error (or enter Q and the number of studies).
- Choose the confidence level.
- Read I², its interval and the pooled estimates.
Worked example
Six studies with Q = 6.39 on 5 degrees of freedom give I² = 21.7%, which might not be important heterogeneity.
How do I interpret I²?
The Cochrane Handbook gives overlapping bands: 0–40% might not be important, 30–60% moderate, 50–90% substantial and 75–100% considerable.
Why show the I² confidence interval?
With few studies I² is very imprecise. A wide interval warns against reading too much into one value.
References
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