Table 2.
Subgroup analysis showing the pooled RRs of DR for CVD mortality
| Subgroups | Studies | Participants | RR (95% CI) | P value | Heterogeneity | |
|---|---|---|---|---|---|---|
| I2, % | P value | |||||
| Type 2 DM | 8 | 7596 | 1.69 (1.27, 2.24) | < 0.001 | 75 | < 0.001 |
| Regions | ||||||
| Asian countries | 5 | 6017 | 2.18 (1.53, 3.11) | < 0.001 | 82 | < 0.001 |
| Western countries | 5 | 4887 | 1.46 (1.22, 1.74) | < 0.001 | 31 | 0.22 |
| Study design | ||||||
| Prospective | 7 | 8132 | 1.54 (1.16, 2.04) | 0.003 | 70 | 0.003 |
| Retrospective | 3 | 2772 | 2.69 (1.49, 4.85) | 0.001 | 84 | 0.002 |
| Data source | ||||||
| Population-based | 3 | 3903 | 1.68 (1.13, 2.52) | 0.010 | 82 | 0.004 |
| Hospital-based | 7 | 7001 | 1.93 (1.31, 2.84) | < 0.001 | 78 | < 0.001 |
| Follow-up period | ||||||
| More than 5 years | 8 | 10,111 | 1.86 (1.40, 2.46) | < 0.001 | 78 | < 0.001 |
| More than 10 years | 5 | 3360 | 1.89 (1.13, 3.16) | 0.020 | 84 | < 0.001 |
| More than 15 years | 2 | 2712 | 1.89 (1.01, 3.56) | 0.049 | 86 | 0.008 |
| After cardiovascular surgery | 2 | 588 | 2.40 (0.63, 9.18) | 0.200 | 94 | < 0.001 |
RR: risk ratio, DR: diabetic retinopathy, CVD: cardiovascular disease, DM: diabetic mellitus, CI: confidence interval