Table 2.
Subgroup analysis of association maternal fever and risk of congenital heart diseases in offspring.
| Measure of heterogeneity | |||||
| Subgroup variables | No. of studies | Pooled OR (95%CI) | χ2 | P | I2 |
| Geographic region | 3.03∗ | .22∗ | 34.1%∗ | ||
| North America | 8 | 1.31 (1.07–1.60) | 28.97 | <.001 | 76.0% |
| Europe | 4 | 1.30 (0.92–1.84) | 12.63 | .01 | 76.0% |
| Asia | 4 | 2.29 (1.25–4.20) | 9.32 | .03 | 68.0% |
| Study design | 6.02∗ | .01∗ | 83.4%∗ | ||
| Cohort | 1 | 1.01 (0.78–1.30) | – | – | – |
| Case-control study | 15 | 1.51 (1.24–1.83) | 74.90 | <.001 | 81.0% |
| Sample source | 1.29∗ | .26∗ | 22.6%∗ | ||
| Hospital | 7 | 1.64 (1.22–2.21) | 13.18 | .04 | 54.0% |
| Population | 9 | 1.33 (1.09–1.63) | 41.35 | <.001 | 81.0% |
| Exposure time | 10.02∗ | .02∗ | 70.1%∗ | ||
| First trimester | 8 | 1.79 (1.32–2.44) | 27.00 | <.001 | 74.0% |
| Pre-pregnancy and pregnancy | 6 | 1.29 (1.01–1.64) | 23.83 | <.001 | 79.0% |
| During pregnancy | 2 | 1.09 (0.87–1.37) | 0.88 | .35 | 0.00% |
| Whether reported the exposure measurement standard | 0.00∗ | .98∗ | 0.00%∗ | ||
| Yes | 6 | 1.42 (1.17–1.74) | 5.62 | .34 | 11.0% |
| No | 10 | 1.43 (1.14–1.80) | 62.01 | <.001 | 85.0% |
| Whether the confounding factors were adjusted | 0.08∗ | .78∗ | 0.00%∗ | ||
| Adjusted | 6 | 1.50 (1.11--2.03) | 21.78 | .001 | 77.0% |
| Unadjusted | 10 | 1.42 (1.13–1.79) | 42.68 | <.001 | 79.0% |
| Quality score | 0.02∗ | .90∗ | 0.00%∗ | ||
| < 7 | 5 | 1.43 (1.07–1.91) | 4.59 | .33 | 13.0% |
| ≥ 7 | 11 | 1.47 (1.19–1.81) | 64.76 | <.001 | 85.0% |