Table 2. Summary of effect estimates.
| Subgroups | No. of studies | Pooled estimates | P-value | heterogeneity | ||
|---|---|---|---|---|---|---|
| I2 | P-value | |||||
| Unmarried | ||||||
| Cohort | 0 | / | / | / | / | |
| case-control | total | 41 | 1.20 [1.07, 1.35] | 0.002 | 82% [77%, 87%] | < 0.00001 |
| population-based | 17 | 1.13 [0.99, 1.29] | 0.07 | 80% [68%, 87%] | < 0.00001 | |
| hospital-based | 24 | 1.23 [1.01, 1.50] | 0.04 | 81% [72%, 87%] | < 0.00001 | |
| subgroup differences | 0.49 | |||||
| Widowed | ||||||
| cohort | (population-based) | 1 | 0.98 [0.93, 1.03] | 0.44 | / | / |
| case-control | total | 13 | 0.96 [0.86, 1.08] | 0.51 | 46% [0%, 72%] | 0.03 |
| population-based | 5 | 0.99 [0.87, 1.13] | 0.89 | 44% [0%, 80%] | 0.13 | |
| hospital-based | 8 | 0.94 [0.75, 1.18] | 0.60 | 47% [0%, 77%] | 0.06 | |
| subgroup differences | 0.70 | |||||
| Divorced | ||||||
| cohort | (population-based) | 1 | 1.04 [0.99, 1.09] | 0.08 | / | / |
| case-control | total | 15 | 1.16 [0.96, 1.39] | 0.12 | 80% [67%, 87%] | < 0.00001 |
| population-based | 6 | 1.03 [0.84, 1.26] | 0.79 | 85% [70%, 93%] | < 0.00001 | |
| hospital-based | 9 | 1.66 [1.02, 2.70] | 0.04 | 77% [55%, 88%] | < 0.0001 | |
| subgroup differences | 0.08 | |||||
| Lifelong single | ||||||
| cohort | (population-based) | 2 | 1.10 [1.04, 1.16] | 0.0004 | 0% [0%, 23%] | 0.33 |
| case-control | total | 25 | 1.24 [1.05, 1.45] | 0.01 | 69% [54%, 80%] | < 0.00001 |
| population-based | 9 | 1.00 [0.93, 1.08] | 0.97 | 0% [0%, 99%] | 0.50 | |
| hospital-based | 16 | 1.51 [1.07, 2.13] | 0.02 | 79% [66%, 87%] | < 0.00001 | |
| subgroup differences | 0.02 | |||||
| Unmarried | ||||||
| Cohort | 0 | / | / | / | / | |
| case-control | total | 41 | 1.20 [1.07, 1.35] | 0.002 | 82% [77%, 87%] | < 0.00001 |
| multi-adjusted | 22 | 1.23 [1.05, 1.45] | 0.01 | 88% [83%, 91%] | < 0.00001 | |
| age-adjusted | 19 | 1.16 [0.99, 1.37] | 0.07 | 65% [43%, 78%] | < 0.0001 | |
| subgroup differences | 0.61 | |||||
| Widowed | ||||||
| cohort | (multi-adjusted) | 1 | 0.98 [0.93, 1.03] | 0.44 | / | / |
| case-control | total | 13 | 0.96 [0.86, 1.08] | 0.51 | 46% [0%, 72%] | 0.03 |
| multi-adjusted | 7 | 1.02 [0.84, 1.23] | 0.85 | 67% [28%, 85%] | 0.005 | |
| age-adjusted | 6 | 0.89 [0.79, 1.02] | 0.09 | 0% [0%, 64%] | 0.80 | |
| subgroup differences | 0.27 | |||||
| Divorced | ||||||
| cohort | (multi-adjusted) | 1 | 1.04 [0.99, 1.09] | 0.08 | / | / |
| case-control | total | 15 | 1.16 [0.96, 1.39] | 0.12 | 80% [67%, 87%] | < 0.00001 |
| Multi-adjusted | 9 | 1.25 [0.97, 1.61] | 0.08 | 87% [78%, 93%] | < 0.00001 | |
| age-adjusted | 6 | 1.02 [0.83, 1.27] | 0.82 | 20% [0%, 64%] | 0.28 | |
| subgroup differences | 0.23 | |||||
| Lifelong single | ||||||
| cohort | (multi-adjusted) | 2 | 1.10 [1.04, 1.16] | 0.0004 | 0% [0%, 23%] | 0.33 |
| case-control | total | 25 | 1.24 [1.05, 1.45] | 0.01 | 69% [54%, 80%] | < 0.00001 |
| multi-adjusted | 16 | 1.28 [1.04, 1.58] | 0.02 | 76% [62%, 85%] | < 0.00001 | |
| age-adjusted | 9 | 1.17 [0.91, 1.49] | 0.22 | 39% [0%, 72%] | 0.11 | |
| subgroup differences | 0.56 | |||||