Table 1

Properties of measures of heterogeneity.

Measure

measured on

increasing with


scale

range

number of studies in meta-analysis

precision (size of studies)


Q

absolute

[0, ∞)

yes

yes

I2

percent

[0, 100%]

no

yes

τ, τ2

outcome

[0, ∞)

no

no

H, H2

absolute

[1, ∞)

no

yes

R, R2

absolute

[1, ∞)

no

yes


Rücker et al. BMC Medical Research Methodology 2008 8:79   doi:10.1186/1471-2288-8-79

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