Table 3

Meta-regression models explaining study heterogeneity on the association between income inequality and mortality

Variables (number of studies)BivariateMultivariate
Model 1Model 2Model 3Model 4
βSEpτ2*βSEpβSEpβSEpβSEp
Intercept0.0270.0230.230.0470.0240.050.0450.0340.190.0450.0240.06
Average population (1000)
 Small: 8–14 (4)Referent
 Large: 470–4880 (5)−0.0330.0250.192.8−3−0.0400.0210.06−0.0100.0260.69−0.0150.0280.59−0.0100.0260.70
 Continuous (per 500 000 population)−0.0040.0030.293.0−3
Median GINI
 <Median (=0.30) (4)ReferentReferent
 ≥Median (5)0.0730.0270.0062.1−30.0770.0250.002
Baseline data
 ≤1990 (6)ReferentReferent
 >1990 (3)0.0570.0220.012.2−30.0520.0260.04
Follow-up duration
 ≤7 years (4)ReferentReferent
 >7 years (5)0.0540.0290.062.6−30.0460.0330.17
Adjusting for area income
 No (5)ReferentReferent
 Yes (4)0.0590.0220.0092.2−30.0540.0250.03
τ2*1.8−32.3−32.7−32.3−3
  • Intercepts in these meta-regression models represent the degree of the associations between income inequality and mortality when explanatory variables are in a referent category or zero (for continuous explanatory variables).

  • * τ2 represents the magnitude of residual heterogeneity.