Table 3 Main results of pooled ORs in meta-analysis of IL-4 (C33T) gene polymorphisms
Subgroup |  | Sample size | Test of association | Test of heterogeneity | Test of publication bias (Begg’s test) | Test of publication bias (Egger’s test) | ||||
|---|---|---|---|---|---|---|---|---|---|---|
Genetic model | Case/Control | OR | 95% CI (p-value) | I2 (%) | P | z | P | t | P | |
Overall | Dominant model | 6587 / 8404 | 1.15 | 1.04–1.26 (≤0.001) | 20.9 | 0.16 | 0.77 | 0.44 | 0.90 | 0.37 |
|  | Recessive model | 6587 / 8404 | 1.16 | 1.06–1.28 ((≤0.001) | 0 | 0.56 | 2.68 | 0.001 | 2.88 | 0.001 |
|  | Allelic model | 6587 / 8404 | 1.14 | 1.07–1.21 (≤0.001) | 27.8 | 0.08 | 2.53 | 0.01 | 2.39 | 0.02 |
|  | CC vs. TT | 6587 / 8404 | 1.21 | 1.02–1.43 (0.02) | 0 | 0.58 | 1.78 | 0.07 | 1.57 | 0.13 |
|  | CT vs. TT | 6587 / 8404 | 1.10 | 1–1.22 (0.05) | 20.5 | 0.17 | 0.23 | 0.81 | 0.56 | 0.58 |
Age subgroups | ||||||||||
Adults | Dominant model | 1678 / 3252 | 1.16 | 0.97–1.40 (0.10) | 0 | 0.54 | −0.98 | 0.32 | −1.43 | 0.19 |
|  | Recessive model | 1678 / 3252 | 1.17 | 0.99–1.39 (0.06) | 0 | 0.93 | 2.41 | 0.01 | 3.57 | 0.007 |
|  | Allelic model | 1678 / 3252 | 1.14 | 1.02–1.26 (0.02) | 0 | 0.75 | 1.01 | 0.31 | 1.44 | 0.18 |
|  | CC vs. TT | 1678 / 3252 | 1.22 | 0.93–1.61 (0.15) | 0 | 0.72 | 0.83 | 0.40 | 0.64 | 0.54 |
|  | CT vs. TT | 1678 / 3252 | 1.09 | 0.90–1.32 (0.91) | 0.2 | 0.43 | −1.16 | 0.24 | −1.72 | 0.12 |
Mixed | Dominant model | 2067 / 1823 | 1.14 | 0.96–1.34 (0.13) | 55.8 | 0.02 | 2.23 | 0.02 | 3.47 | 0.01 |
|  | Recessive model | 2067 / 1823 | 1.08 | 0.84–1.40 (0.53) | 0 | 0.89 | −0.49 | 0.62 | 0.47 | 0.67 |
|  | Allelic model | 2067 / 1823 | 1.14 | 1.01–1.29 (0.03) | 56.9 | 0.02 | 2.72 | 0.007 | 3.11 | 0.02 |
|  | CC vs. TT | 2067 / 1823 | 1.10 | 0.77–1.57 (0.60) | 0 | 0.88 | 1.47 | 0.14 | 2.01 | 0.13 |
|  | CT vs. TT | 2067 / 1823 | 1.13 | 0.95–1.35 (0.15) | 53.7 | 0.03 | 2.47 | 0.01 | 3.38 | 0.01 |
Children | Dominant model | 2842 / 3333 | 1.15 | 0.99–1.34 (0.07) | 12.4 | 0.33 | −0.42 | 0.67 | −0.48 | 0.64 |
|  | Recessive model | 2842 / 3333 | 1.18 | 1.03–1.35 (0.01) | 54 | 0.03 | 1.24 | 0.21 | 2.34 | 0.05 |
|  | Allelic model | 2842 / 3333 | 1.13 | 1.04–1.24 (≤0.001) | 44.6 | 0.07 | 0.42 | 0.67 | 0.47 | 0.65 |
|  | CC vs. TT | 2842 / 3333 | 1.27 | 0.97–1.65 (0.08) | 42.3 | 0.09 | 0.99 | 0.32 | 0.97 | 0.36 |
|  | CT vs. TT | 2842 / 3333 | 1.08 | 0.92–1.26 (0.33) | 4.5 | 0.39 | −0.42 | 0.67 | −0.64 | 0.54 |
Continent subgroups | ||||||||||
Asia | Dominant model | 3634 / 5371 | 1.10 | 0.93–1.130 (0.25) | 29.3 | 0.13 | 0.81 | 0.41 | 1.44 | 0.17 |
|  | Recessive model | 3634 / 5371 | 1.14 | 1.02–1.26 (0.01) | 0 | 0.56 | 0.85 | 0.39 | 1.24 | 0.24 |
|  | Allelic model | 3634 / 5371 | 1.12 | 1.03–1.21 (≤0.001) | 34.9 | 0.08 | 2.31 | 0.02 | 2.70 | 0.01 |
|  | CC vs. TT | 3634 / 5371 | 1.08 | 0.87–1.33 (0.49) | 0 | 0.77 | 0 | 1 | 0.09 | 0.93 |
|  | CT vs. TT | 3634 / 5371 | 1.02 | 0.89–1.18 (0.76) | 29.6 | 0.12 | 0.45 | 0.65 | 0.93 | 0.36 |
Europe | Dominant model | 1129 / 1008 | 1.23 | 1.01–1.50 (0.03) | 48.3 | 0.12 | −0.68 | 0.49 | −0.64 | 0.58 |
|  | Recessive model | 1129 / 1008 | 2.94 | 1.54–5.62 (≤0.001) | 0 | 0.95 | −0.52 | 0.60 | −0.85 | 0.55 |
|  | Allelic model | 1129 / 1008 | 1.30 | 1.10–1.54 (≤0.001) | 31.2 | 0.22 | 0 | 1 | −0.68 | 0.56 |
|  | CC vs. TT | 1129 / 1008 | 3 | 1.56–5.76 (≤0.001) | 0 | 0.87 | −0.52 | 0.60 | −1.20 | 0.44 |
|  | CT vs. TT | 1129 / 1008 | 1.13 | 0.92–1.38 (0.24) | 52.8 | 0.09 | −0.68 | 0.49 | −0.59 | 0.61 |
America | Dominant model | 1181 / 1278 | 1.26 | 1.05–1.51(≤0.001) | 0 | 0.76 | 0.45 | 0.65 | 0.54 | 0.61 |
|  | Recessive model | 1181 / 1278 | 1.16 | 0.88–1.52 (0.29) | 0 | 0.89 | 2.55 | 0.01 | 6.60 | 0.06 |
|  | Allelic model | 1181 / 1278 | 1.17 | 1.03–1.33 (0.01) | 0 | 0.55 | 1.65 | 0.09 | 2.71 | 0.04 |
|  | CC vs. TT | 1181 / 1278 | 1.26 | 0.93–1.71 (0.14) | 0 | 0.84 | 2.25 | 0.02 | 3.17 | 0.05 |
|  | CT vs. TT | 1181 / 1278 | 1.23 | 1.02–1.49 (0.03) | 0 | 0.85 | 0.45 | 0.65 | 0.18 | 0.86 |
Ethnicity subgroups | ||||||||||
Caucasian | Dominant model | 5881 / 7710 | 1.15 | 1.04–1.28 (0.008) | 30.7 | 0.08 | 0.78 | 0.43 | 0.69 | 0.50 |
|  | Recessive model | 5881 / 7710 | 1.17 | 1.06–1.30 (0.002) | 6.7 | 0.3 | 1.98 | 0.04 | 2.44 | 0.02 |
|  | Allelic model | 5881 / 7710 | 1.14 | 1.07–1.22 (≤0.001) | 35.7 | 0.04 | 1.87 | 0.06 | 1.79 | 0.08 |
|  | CC vs. TT | 5881 / 7710 | 1.23 | 1.01–1.49 (0.03) | 4.6 | 0.4 | 1.14 | 0.25 | 0.72 | 0.48 |
|  | CT vs. TT | 5881 / 7710 | 1.1 | 0.98–1.22 (0.09) | 30.6 | 0.08 | −0.68 | 0.49 | −0.59 | 0.61 |
African-American | Dominant model | 706 / 698 | 1.14 | 0.89–1.45 (0.29) | 0 | 0.76 | 0.45 | 0.65 | 0.54 | 0.61 |
|  | Recessive model | 706 / 698 | 1.08 | 0.80–1.46 (0.6) | 0 | 0.87 | 2.55 | 0.01 | 6.60 | 0.06 |
|  | Allelic model | 706 / 698 | 1.08 | 0.93–1.27 (0.32) | 0 | 0.74 | 1.65 | 0.09 | 2.71 | 0.04 |
|  | CC vs. TT | 706 / 698 | 1.16 | 0.82–1.62 (0.4) | 0 | 0.79 | 2.25 | 0.02 | 3.17 | 0.05 |
|  | CT vs. TT | 706 / 698 | 1.13 | 0.87–1.45 (0.35) | 0 | 0.8 | 0.45 | 0.65 | 0.18 | 0.86 |