Table 2

Model parameters of the mixed effects model

Model fit
Random effects
Factorσ2σCochran’s Q Test for heterogeneity
P value
Fixed effects
FactorEstimateP valueLower 95% CIUpper 95% CI
Time to reperfusion, hours−13.1<0.001−14.6−11.5
  • *Exploration of heterogeneity: Separate inclusion of the timing of MRI (χ2(1)=11.5, p<0.001), T2-weighted MRI interpretation method (χ2(2)=7.8, p=0.020), T1-weighted late gadolinium enhancement MRI interpretation method (χ2(5)=15.3, p=0.009) and gender distribution (χ2(1)=11.3, p<0.001) resulted in a significantly better fit of the mixed effects model, while the inclusion of the T2-weighted MRI sequence (χ2(3)=5.6, p=0.131), T1-weighted late gadolinium enhancement MRI sequence (χ2(1)=0.5, p=0.468) and mean age (χ2(1)<0.1, p=0.995) did not. Inclusion of all significant confounding variables reduced the between-study heterogeneity by 45.2% to σ2=91.9 (see online supplemental table 4).

  • AIC, Akaike information criterion; BIC, Bayesian information criterion; logLik, log-likelihood.