Final answer:
The Inconsistency Index or I^2 statistic is a measure used in meta-analysis to assess the degree of heterogeneity among studies.
Step-by-step explanation:
The Inconsistency Index or I2 statistic is a measure used in meta-analysis to assess the degree of heterogeneity among studies. It quantifies the proportion of total variation in effect sizes that can be attributed to heterogeneity rather than sampling error. It ranges from 0% to 100%, with higher values indicating greater inconsistency.
The formula for calculating the Inconsistency Index is:
I2 = (Q - df) / Q * 100%
Where Q is the Cochran's Q statistic, and df is the degrees of freedom. The Q statistic measures the extent of heterogeneity in the effect sizes across the studies.