Table 4

Summary Outcome Measures for Emergency Room Visits.

Measure

Effect Size

Confidence Interval

Effect Size P-value

Homogeneity Test P-value


SMDa

Fixed-effects

-0.21

-0.33, -0.09

<0.001

0.05

Random-effects

-0.27

-0.45, -0.09

0.003

0.05

IRDb

Fixed-effects M-H

-0.04

-0.05, -0.03

<0.001

<0.001

Random-effects

-0.05

-0.08, -0.03

<0.001

<0.001

IRRc

Fixed-effects M-H

0.66

0.59, 0.74

<0.001

<0.001

PR + study indicators

0.66

0.54, 0.81

<0.001

<0.001

PR – study indicators

0.77

0.59, 0.99

0.039

N/A


a SMD refers to standardized mean difference and was obtained using both fixed effects and random effects models. b IRD refers to the incidence rate difference, and was obtained using a Mantel-Haenszel procedure to estimate a fixed-effects model and an inverse-variance method to estimate a random-effects model. c IRR refers to the incidence rate ratio and was obtained using Mantel-Haenszel procedure to estimate a fixed effects model and Poisson regression models with Huber-White sandwich estimators with and without study indicators which is equivalent to a random-effects model.

Guevara et al. BMC Medical Research Methodology 2004 4:17   doi:10.1186/1471-2288-4-17

Open Data