Xuxi Zhang

Effects on DR progression A total of 10 studies from 6 articles 6, 12, 16, 18, 19, 21 provided data on the number of patients with DR progression. There are two articles 19, 21 each reporting the results on three studies. Out of the 10 studies, 5 studies from 4 articles 12, 16, 19, 21 found a significant reduction in the progression of DR in intervention group compared with control group, and 5 studies from 4 articles 6, 18, 19, 21 showed no effect. Results on the effectiveness of all interventions targeting modifiable risk factors of DR in reducing the risk of DR progression among patients with type 2 diabetes are presented in Figure 4. The pooled results revealed that interventions targeting modifiable risk factor of DR reduced the risk of DR progression among patients with type 2 diabetes significantly (OR = 0.74; 95% CI 0.59 to 0.92; P = 0.007). The overall heterogeneity among studies was substantial ( I 2 = 72.4%). The sensitivity of the 10 studies was low, and the Begg and Egger tests did not reveal publication bias. More details of sensitivity analysis and publication bias assessment can be found in Supplementary Figure S5 and S6. Results of subgroup analyses on the effectiveness of different types of interventions are presented in Figure 4, Part A. Blood ‐ pressure ‐ control intervention had no effect on reducing the risk of DR progression (OR = 1.05; 95% CI 0.77 to 1.45; P = 0.749), and there was no heterogeneity ( I 2 = 0%). Glycemic ‐ control intervention reduced the risk of DR progression significantly (OR = 0.71; 95% CI 0.52 to 0.97; P = 0.032), and the heterogeneity was substantial ( I 2 = 81.6%). Lipid ‐ control intervention had no significant effect on reducing the risk of DR progression (OR = 0.83; 95% CI 0.44 to 1.59; P = 0.581), and the heterogeneity was substantial ( I 2 = 79.5%). Multifactorial intervention reduced the risk of DR progression significantly (OR = 0.39; 95% CI 0.23 to 0.65; P <0.001), and there was no heterogeneity among multifactorial intervention studies ( I 2 = 0%). Results of subgroup analyses on different follow ‐ up intervals are presented in Figure 4, Part B. There was substantial heterogeneity among interventions with follow ‐ up of 2 ‐ 5 years ( I 2 = 66.4%). Interventions with follow ‐ up of 2 ‐ 5 years reduced the risk of DR progression significantly (OR = 0.73; 95% CI 0.59 to 0.91; P = 0.006). There was substantial heterogeneity among interventions with follow ‐ up of over 5 years ( I 2 = 85.9%). Interventions with follow ‐ up of over 5 years had no significant effect on reducing the risk of DR progression (OR = 0.84; 95% CI 0.39 to 1.80; P = 0.648). 172 Chapter 7