Table 3.
Detailed outcomes on insulin use and RRs of DR
|
Subgroups |
No. of studies |
Pooled estimate |
Tests of heterogeneity |
||
|---|---|---|---|---|---|
| RR | 95% CI | P value | I 2 (%) | ||
| All subjects |
7 |
2.30 |
1.35-3.93 |
< 0.001 |
89.3 |
| Study design |
|
|
|
|
|
| Prospective study |
6 |
2.38 |
1.28-4.41 |
< 0.001 |
90.9 |
| Retrospective study |
1 |
2.30 |
1.11-3.43 |
— |
— |
| Geographic location |
|
|
|
|
|
| Europe |
5 |
1.85 |
1.12-3.08 |
< 0.001 |
80.4 |
| Asia |
1 |
3.43 |
1.93-6.08 |
— |
— |
| North America |
1 |
4.90 |
2.63-5.79 |
— |
— |
| Data source |
|
|
|
|
|
| Population based |
5 |
2.94 |
2.19-3.94 |
0.234 |
28.1 |
| Hospital based |
2 |
1.34 |
0.65-2.76 |
0.024 |
80.5 |
| Follow-up duration |
|
|
|
|
|
| ≥ 5 years |
1 |
3.51 |
1.59-7.76 |
— |
— |
| < 5 years |
6 |
2.17 |
1.22-3.85 |
< 0.001 |
90.3 |
| Major confounders adjusted |
|
|
|
|
|
| DM duration |
|
|
|
|
|
| Yes |
3 |
2.18 |
0.80-5.93 |
< 0.001 |
91.7 |
| No |
4 |
2.53 |
1.74-3.67 |
0.115 |
49.4 |
| HbA1c |
|
|
|
|
|
| Yes |
3 |
2.88 |
2.00-4.14 |
0.454 |
0 |
| No | 4 | 2.30 | 1.35-4.14 | < 0.001 | 92.7 |
RR: relative risk; CI: confidence interval; DM: diabetes mellitus.