Xuxi Zhang

bias fewer to 344 fewer) DR Progression: Follow ‐ up 2 ‐ 5 years (follow ‐ up 3.8 to 5 years) 7 randomised trials no serious risk of bias serious 1 no serious indirectness no serious imprecision none 700/9185 (7.6%) 825/9120 (9%) OR 0.73 (0.59 to 0.91) 23 fewer per 1000 (from 7 fewer to 35 fewer)  MODERATE IMPORTANT DR Progression: Follow ‐ up >5 years (follow ‐ up 8 years) 3 randomised trials no serious risk of bias very serious 1 no serious indirectness no serious imprecision none 47/399 (11.8%) 37/363 (10.2%) OR 0.84 (0.39 to 1.80) 15 fewer per 1000 (from 60 fewer to 68 more)  LOW IMPORTANT 1 Substantial heterogeneity 2 Only two studies DR, diabetic retinopathy 200 Chapter 7