| Subgroup analyses | Results from meta-regression | |||||||
---|---|---|---|---|---|---|---|---|---|
Results | Heterogeneity | ||||||||
Variable | Subgroup | Number of studies | OR | 95% CI | P-value | I 2 | Coefficient | SD | P-value |
Outcome measurement | Mixed | 3 | 1.199 | 0.985–1.460 | 0.000 | 90% | Reference | ||
Formal | 10 (14 different samples) | 1.153 | 1.094–1.215 | 0.000 | 81% | −0.0335 | 0.0591 | 0.571 | |
Determinant measurement | Dichotomous | 5 (9 different samples) | 1.256 | 1.001–1.577 | 0.000 | 86% | Reference | ||
Continuous | 8 | 1.130 | 1.082–1.179 | 0.000 | 80% | −0.0922 | 0.0579 | 0.111 | |
Proportion of volunteers (%) in baseline study sample | Continuous | 9a (13 different samples) | 1.162 | 1.104–1.223 | 0.000 | 79% | −0.0001 | 0.0001 | 0.176 |
0–100% | 10 | 1.147 | 1.088–1.208 | 0.000 | 87% | Reference |  |  | |
0% | 2 (3 different samples) | 1.564 | 1.321–1.853 | 0.667 | 0% | 0.3080 | 0.1100 | 0.005 | |
100% | 3 (4 different samples) | 1.171 | 0.870–1.577 | 0.024 | 68% | 0.0083 | 0.0720 | 0.908 | |
Mean age at baseline | Continuous | 10b (13 different samples) | 1.111 | 1.064–1.161 | 0.000 | 77% | 0.0001 | 0.0001 | 0.493 |
≤ 55 years | 7 (8 different samples) | 1.148 | 1.025–1.286 | 0.000 | 84% | Reference |  |  | |
>  55 years | 7 (9 different samples) | 1.203 | 1.128–1.284 | 0.000 | 84% | 0.0711 | 0.0576 | 0.217 | |
Continent | USA | 6 | 1.144 | 1.075–1.218 | 0.000 | 84% | Reference | ||
Europe | 6 (10 different samples) | 1.186 | 1.055–1.333 | 0.000 | 77% | 0.0110 | 0.0598 | 0.854 | |
Australia | 1 | 1.430 | 1.283–1.594 | N.A. | N.A. | 0.2164 | 0.1049 | 0.039 | |
Year of baseline measurement | Continuous | 13 (17 different samples) | 1.171 | 1.114–1.232 | 0.000 | 83% | N.A. |  |  |
<  2006 | 11 (13 different samples) | 1.187 | 1.125–1.252 | 0.000 | 86% | Reference |  |  | |
≥ 2006 | 3 (4 different samples) | 1.081 | 0.852–1.372 | 0.132 | 47% | −0.1167 | 0.0810 | 0.150 | |
Duration of follow-up | Continuous | 13 (17 different samples) | 1.171 | 1.114–1.232 | 0.000 | 83% | N.A. |  |  |
≤ 3 years | 5 (9 different samples) | 1.241 | 1.114–1.382 | 0.003 | 66% | Reference |  |  | |
4–7 years | 2 | 1.062 | 0.974–1.157 | 0.104 | 62% | −0.1728 | 0.1068 | 0.106 | |
≥ 8 years | 6 | 1.225 | 1.081–1.389 | 0.000 | 91% | −0.0225 | 0.0840 | 0.789 | |
Risk of bias items | |||||||||
 Study participation | Unclear/high risk of bias | 3 (4 different samples) | 1.144 | 1.089–1.203 | 0.000 | 84% | Reference | ||
Low risk of bias | 11 (13 different samples) | 1.396 | 0.973–2.004 | 0.007 | 75% | 0.1620 | 0.0766 | 0.034 | |
 Study confounding | Unclear/high risk of bias | 2 | 1.199 | 1.089–1.321 | 0.387 | 0% | Reference | ||
Low risk of bias | 11 (15 different samples) | 1.171 | 1.110–1.235 | 0.000 | 85% | −0.0105 | 0.0880 | 0.905 |