Xuxi Zhang

through meta ‐ analysis among relevant randomized control trials (RCTs). METHODS Data sources and searches We searched Pubmed, ScienceDirect and Web of science to identify articles related to our study from their beginning to November 3 rd , 2014. According to relevant definitions of peer support and the seven types of peer support, keywords used in searching were “type 2 diabetes”, “T2DM”, “self ‐ management”, “peer support”, “peer group”, “peer coach”, “peer education” and “community health worker”. We did not enclose the phrases used in searching in order to achieve a broad enough search scope. In addition, only articles published in English were considered. In Pubmed, we conducted searches in all fields and identified 352 articles. In both ScienceDirect and Web of science, we conducted searching in title/abstract/keywords and identified 52 articles from ScienceDirect and 30 from Web of Science after excluding duplicates. Details of the search syntax are in Supplementary Data. We also examined the references in review articles like systematic reviews and meta ‐ analysis to identify studies not captured through database searching. A systematic review on peer support covering 22 studies from Pubmed addressing peer support in diabetes published between January 1, 2000 and June, 2014 was included. 12 The review focused on the function and effect of peer support on several chronic diseases and searched more synonyms of peer support like promotores , doula, dumas and embajadores, therefore its search scope was broader than ours. We found 10 articles different from ours among these 22 and added them to our data sources. Study selection We only included original research of RCTs that studied the effect of peer support intervention for patients with T2DM and provided basic information and outcomes (e.g., mean and standard deviation of HbA 1c or relevant data fromwhich we can derive the mean and standard deviation) which could be used to evaluate the effect on glycemic control. Moreover, only studies in which all or most subjects had type 2 diabetes were eligible. If the type of diabetes was unclear, then the study was included if the mean age of patients was more than 30 because most of these patients were likely to have type 2 diabetes. However, studies with subjects under 18 years old were excluded because peer support methods for adults are likely to be different from those for children and adolescents and this meta ‐ analysis was intended to focus on T2DM among adults. In addition, studies with support intervention provided by professionals were excluded. Of 444 articles with identified abstracts from Pubmed, ScienceDirect, Web of Science and references, we excluded 367 that were not original research (e.g., reviews, secondhand ‐ data analysis, etc.); did not study the effect of peer support; did not provide relevant information on glycemic control; studied type 1 diabetes, gestational diabetes or other specific diabetes types; were not RCTs; studied patients under 18 years old; did not have qualified peer support 130 Chapter 6