Xuxi Zhang

Worsening) (The details are presented in Supplementary Table S5 and S6). Quality of the evidence for most results on DR progression was moderate to low (The details are presented in Supplementary Table S7), which was mainly caused by the substantial heterogeneity in this subgroup. Results of intervention effects on DR prevention A total of 11 studies from 10 articles 5, 7, 8, 10, 11, 13 ‐ 15, 17, 20 provided data on the number of patients with newly developed DR. In one article 20 , there were two intervention groups (Mediterranean diet supplemented with extra virgin olive oil group and Mediterranean diet supplemented with mixed nuts group) and one control group. Therefore, we divided this study into two studies by matching the control group with two intervention groups separately. Out of the 11 studies, 7 studies from 6 articles 7, 10, 11, 13, 17, 20 revealed a significant reduction in the number of newly developed DR in intervention group compared with control group, and 4 studies from 4 articles 5, 8, 14, 15 showed no effect. Results on the effectiveness of all interventions targeting modifiable risk factors of DR in reducing the risk of developing DR among patients with type 2 diabetes are presented in Figure 2. Heterogeneity between studies was small ( I 2 = 26.7%). The pooled results indicated that interventions targeting modifiable risk factor of DR reduced the risk of developing DR among patients with type 2 diabetes significantly (OR = 0.60; 95% CI 0.45 to 0.79; P < 0.001). The sensitivity of the 11 studies was low, and the Begg and Egger tests did not reveal publication bias. More details on the sensitivity analysis and publication bias assessment can be found in Supplementary Figure S1 and S2. Results of subgroup analyses on the effectiveness of different types of interventions are presented in Figure 2, Part A. There was moderate heterogeneity among blood ‐ pressure ‐ control intervention studies ( I 2 = 41.9%). Blood ‐ pressure ‐ control intervention had no significant effect on reducing the risk of developing DR (OR = 0.68; 95% CI 0.41 to 1.14; P = 0.143). There was moderate heterogeneity among glycemic ‐ control intervention studies ( I 2 = 38.2%). Glycemic ‐ control intervention had no significant effect on reducing the risk of developing DR (OR = 0.70; 95% CI 0.31 to 1.57; P = 0.387). There was no heterogeneity between dietary ‐ control intervention studies ( I 2 = 0%). Dietary ‐ control intervention reduced the risk of developing DR significantly (OR = 0.64; 95% CI 0.43 to 0.95; P = 0.025). There was no heterogeneity among multifactorial intervention studies ( I 2 = 0%). Multifactorial intervention reduced the risk of developing DR significantly (OR = 0.27; 95% CI 0.14 to 0.53; P < 0.001). 168 Chapter 7