Table 2.
Subgroup analyses of zinc level and preeclampsia (PE).
| Subgroup | Number of Studies | SMD (95% CI) | Test of SMD = 0 | Heterogeneity | Article Included | ||
|---|---|---|---|---|---|---|---|
| Z | p for Z | I2 | p for I2 | ||||
| Continent | |||||||
| Asia Europe Africa |
10 2 2 |
−0.812 (−1.263, −0.362) 0.323 (−0.033, 0.678) −0.389 (−0.971, 0.194) |
3.54 1.78 1.31 |
0.0001 0.075 0.191 |
88.4 0.0 72.2 |
0.0001 0.734 0.058 |
[11,12,13,17,25,26,27,28,29,31] [24,30] [23,32] |
| Sample type | |||||||
| plasma serum |
4 10 |
−0.460 (−1.246, 0.325) −0.637 (−1.080, −0.195) |
1.15 2.82 |
0.251 0.005 |
87.7 89.4 |
0.0001 0.0001 |
[12,29,30,32] [11,13,17,23,24,25,26,27,28,31] |
| Fasting status | |||||||
| yes no |
8 6 |
−0.636 (−1.131, −0.141) −0.522 (−1.159, 0.115) |
2.52 1.61 |
0.012 0.108 |
89.2 89.4 |
0.0001 0.0001 |
[11,12,13,17,24,27,28,30] [23,25,26,29,31,32] |
| Individual age match | |||||||
| yes no |
7 7 |
−0.634 (−1.213, −0.056) −0.540 (−1.060, −0.019) |
2.15 2.03 |
0.032 0.042 |
89.9 88.2 |
0.0001 0.0001 |
[13,23,25,26,29,31,32] [11,12,17,24,27,28,30] |
| Individual gestational age match | |||||||
| yes no |
6 8 |
−0.678 (−1.325, −0.030) −0.516 (−0.983, −0.050) |
2.05 2.17 |
0.040 0.030 |
91.5 86.0 |
0.0001 0.0001 |
[11,13,25,29,31,32] [12,17,23,24,26,27,28,30] |
Abbreviations: SMD: standard mean difference; CI: confidence interval.