I2 represents the amount of heterogeneity relative to the total amount of variance in the observed effect sizes (Higgins & Thompson, 2002). For three-level meta-analyses, it is additionally broken down into I2_w (amount of within-cluster heterogeneity) and I2_b (amount of between-cluster heterogeneity).
Value
Numeric matrix, with rows corresponding to I2 (total heterogeneity), and optionally I2_w and I2_b (within- and between-cluster heterogeneity).
Examples
I2(matrix(1:20, ncol = 1))
#> mean sd 2.5% 25% 50% 75% 97.5%
#> [1,] 10.5 5.91608 1.475 5.75 10.5 15.25 19.525