title: Peer Support Interventions for Adults With Diabetes: A Meta-Analysis of Hemoglobin A1cOutcomes.
abstract: Peer support intervention trials have shown varying effects on glycemic control. We aimed to estimate the effect of peer support interventions delivered by people affected by diabetes (those with the disease or a caregiver) on hemoglobin A1c(HbA1c) levels in adults.
  
  
  
  We searched multiple databases from 1960 to November 2015, including Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, CINAHL, and Scopus. We included randomized controlled trials (RCTs) of adults with diabetes receiving peer support interventions compared with otherwise similar care. Seventeen of 205 retrieved studies were eligible for inclusion. Quality was assessed with the Cochrane risk of bias tool. We calculated the standardized mean difference (SMD) of change in HbA1clevel from baseline between groups using a random effects model. Subgroup analyses were predefined.
  
  
  
  Seventeen studies (3 cluster RCTs, 14 RCTs) with 4,715 participants showed an improvement in pooled HbA1clevel with an SMD of 0.121 (95% CI, 0.026-0.217;P= .01; I2= 60.66%) in the peer support intervention group compared with the control group; this difference translated to an improvement in HbA1clevel of 0.24% (95% CI, 0.05%-0.43%). Peer support interventions showed an HbA1cimprovement of 0.48% (95% CI, 0.25%-0.70%;P<.001; I2= 17.12%) in the subset of studies with predominantly Hispanic participants and 0.53% (95% CI, 0.32%-0.73%;P<.001; I2= 9.24%) in the subset of studies with predominantly minority participants; both were clinically relevant. In sensitivity analysis excluding cluster RCTs, the overall effect size changed little.
  
  
  
  Peer support interventions for diabetes overall achieved a statistically significant but minor improvement in HbA1clevels. These interventions may, however, be particularly effective in improving glycemic control for people from minority groups, especially those of Hispanic ethnicity.
authors.affiliation: Department of Family and Community Medicine, University of Missouri, Columbia, Missouri patilso@health.missouri.edu.
authors.forename: Sonal J
authors.initials: SJ
authors.lastname: Patil
authors.affiliation: Sinclair School of Nursing, University of Missouri, Columbia, Missouri.
authors.forename: Todd
authors.initials: T
authors.lastname: Ruppar
authors.affiliation: Department of Family and Community Medicine, University of Missouri, Columbia, Missouri.
authors.forename: Richelle J
authors.initials: RJ
authors.lastname: Koopman
authors.affiliation: Department of Family and Community Medicine, University of Missouri, Columbia, Missouri.
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Lindbloom
authors.affiliation: Department of Family and Community Medicine, University of Missouri, Columbia, Missouri.
authors.forename: Susan G
authors.initials: SG
authors.lastname: Elliott
authors.affiliation: Department of Family and Community Medicine, University of Missouri, Columbia, Missouri.
authors.forename: David R
authors.initials: DR
authors.lastname: Mehr
authors.affiliation: Sinclair School of Nursing, University of Missouri, Columbia, Missouri.
authors.forename: Vicki S
authors.initials: VS
authors.lastname: Conn
mesh_terms: D000328:Adult; D003376:Counseling; D003920:Diabetes Mellitus / Q000097:blood / Q000628:therapy*; D006442:Glycated Hemoglobin / Q000032:analysis*; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008913:Minority Groups; D010379:Peer Group; D016032:Randomized Controlled Trials as Topic; D012944:Social Support
chemical_list: D006442:Glycated Hemoglobin
keywords: diabetes mellitus; glycemic control; hemoglobin A1c; peer support; self-efficacy; support groups