Xuxi Zhang

Third, how long should follow ‐ up interval of interventions be to better reduce the risk of developing DR and/or its worsening? MATERIALS AND METHODS Data sources and searches Pubmed, Embase and ScienceDirect were searched with terms related to our study aim, including “prevention”, “intervention”, “glycemic control”, “HbA1c”, “blood pressure control”, “lipids”, “diet”, “physical activity”, “smoking”, “diabetic retinopathy”, “DR”, “type 2 diabetes”, “T2DM” and other synonyms to identify articles related to our study from January 1 st , 1980 to June 1 st , 2019. PubMed was searched with MeSH terms and other synonyms in title/abstract/keywords and identified 503 articles. Embase was searched with Emtree terms and other synonyms in title/abstract/keywords and identified 1008 articles. ScienceDirect was searched with keywords in title/abstract/keywords of research articles and identified 885 articles. After excluding duplicates, a total of 1991 articles were identified, and details of the search syntax can be found in the Supplementary Data. Study selection Eligible studies were screened from the 1991 articles based on the inclusion and exclusion criteria below. Inclusion criteria:  1. Studies with a randomized ‐ controlled design presenting original research 2. Study participants: patients with type 2 diabetes (If the type of diabetes was unclear, the study was included if the mean age of patients was over 30 because most of these patients were likely to have type 2 diabetes.) 3. Studies that aimed to study the effect of interventions targeting modifiable risk factors of DR (including blood glucose, blood pressure, lipid, dietary, physical activity and smoking) on the prevention and control of DR 4. Studies that provided data that could be used to calculate Odds Ratio (OR) in order to evaluate the effect of interventions targeting modifiable risk factors of DR on the prevention and control of DR (e.g. The number of patients who developed or did not develop DR in both intervention group (IG) and control group (CG); the number of DR patients whose condition worsened or did not worsen in both groups; or other related data from which the useful data could be derived) Exclusion criteria:  1. Study participants: Patients under 18 years old 2. The intervention is medical treatment of DR rather than just targeting modifiable risk factors of DR (e.g. drugs, medical examinations, and surgeries) 3. Non ‐ English publications 164 Chapter 7