Table 2 Pooled and subgroup analyses
From: Effect of low birth weight on childhood asthma: a meta-analysis
Stratification | Number of study | Model | Heterogeneity statistics | ||
|---|---|---|---|---|---|
Fixed-effects model (RR, 95% CI) | Random-effects model (RR, 95% CI) | I2 | P value | ||
Overall | 13 | 1.162 (1.128-1.197) | 1.152 (1.082-1.222) | 40.2% | 0.066 |
Geographic area | |||||
Europe | 6 | 1.18 (1.09-1.27) | 1.18 (1.09-1.27) | 0% | 0.450 |
North America | 4 | 1.16 (1.12-1.20) | 1.17 (1.00-1.34) | 78.9% | 0.003 |
Other | 3 | 1.17 (1.08-1.25) | 1.17 (1.08-1.25) | 0% | |
Study population size | |||||
< 5000 | 8 | 1.21 (1.03-1.39) | 1.23 (1.20-1.22) | 21.7% | 0.257 |
≥ 5000 | 5 | 1.16 (1.12-1.20) | 1.14 (1.07-1.21) | 63.1% | 0.029 |
Publication year | |||||
1997-2005 | 6 | 1.01 (0.91-1.10) | 1.01 (0.91-1.10) | 0% | 0.857 |
2006-2013 | 7 | 1.19 (1.15-1.22) | 1.19 (1.15-1.23) | 2.3% | 0.408 |
Adjusted RR | |||||
Yes | 5 | 1.16 (1.12-1.20) | 1.14 (1.04-1.25) | 67.9% | 0.014 |
No | 8 | 1.17 (1.09-1.25) | 1.17 (1.06-1.28) | 7.8% | 0.370 |
Study population age (year) | |||||
≤ 10 | 7 | 1.16 (1.13-1.20) | 1.17 (1.06-1.28) | 64.5% | 0.010 |
> 10 | 6 | 1.15 (1.07-1.23) | 1.15 (1.07-1.23) | 0% | 0.692 |