Table 2.
Subgroup analyses between female and male groups.
| Subgroups | Categories (No. of studies) | Sample size | OR | 95% CI (%) | I2 (%) | P-value within subgroup | Q (P-value across subgroups) | ||
|---|---|---|---|---|---|---|---|---|---|
| Female | Male | Lower | Upper | ||||||
| Year of survey (years) | 1990–2004 (4) | 5,625 | 5,397 | 1.23 | 1.11 | 1.37 | 77.60 | 0.004 | 0.51 (0.48) |
| 2007–2012 (4) | 131,447 | 180,483 | 1.79 | 1.74 | 1.84 | 94.52 | <0.001 | ||
| Study design | Case-control (1) | 124,550 | 174,638 | 1.79 | 1.73 | 1.84 | <0.001 | 1.00 | 19.39 (<0.001) |
| Cohort (2) | 2,681 | 2,239 | 1.11 | 0.99 | 1.26 | 64.41 | 0.09 | ||
| Cross-sectional (10) | 12,118 | 10,628 | 1.79 | 1.67 | 1.93 | 85.34 | <0.001 | ||
| Sampling method | Consecutive (1) | 5,215 | 4,631 | 2.03 | 1.84 | 2.23 | <0.001 | 1.00 | 22.55 (<0.001) |
| Multi-stage stratified (2) | 2,313 | 1,840 | 1.30 | 1.11 | 1.52 | <0.001 | 0.47 | ||
| Random (6) | 127,171 | 176,444 | 1.77 | 1.72 | 1.82 | 89.90 | <0.001 | ||
| Type of interview | Face to face (5) | 129,520 | 179,464 | 1.73 | 1.68 | 1.78 | 95.67 | <0.001 | 3.39 (0.07) |
| Telephone (4) | 2,119 | 1,382 | 1.85 | 1.54 | 2.23 | <0.001 | 0.60 | ||
| Mean age (years) | ≤44.7 (5) | 132,164 | 181,162 | 1.86 | 1.80 | 1.91 | 95.01 | <0.001 | 0.85 (0.36) |
| >44.7 (4) | 2,469 | 1,668 | 1.31 | 1.12 | 1.53 | 91.30 | <0.001 | ||
| Continent | Africa (1) | 1,157 | 995 | 1.25 | 1.04 | 1.51 | <0.001 | 0.02 | 7.14 (0.07) |
| Asia (2) | 2,308 | 2,620 | 1.77 | 1.46 | 2.15 | <0.001 | <0.001 | ||
| Europe (6) | 7,444 | 6,373 | 1.84 | 1.69 | 2.00 | 91.50 | <0.001 | ||
| North America (4) | 128,440 | 177,571 | 1.75 | 1.70 | 1.80 | 93.66 | <0.001 | ||
Q, Cochran's Q. Bold-value: p < 0.05.
OR, odds ratio; CI, confidence interval.