I2 값이 25%이면 이질성이 낮은 것으로, 50%이면 이질성이 중간인 것으로, 75% 이상이면 이질성이 높은 것으로 판단하였다.
If the I2 value ended up being 25%, the heterogeneity was low, if it had been 50%, the heterogeneity was medium, and if it had been 75% or more, the heterogeneity was high.