Table 1

Descriptive Summary of the Characteristics of Included Studies

Study, YearPatients, No.Setting, PopulationInterventionControlDuration of Peer TrainingPeer SupervisionAttendance Rates, Intensity
Keyserling et al,23 2002133United States: African American women
Mean HbA1c 11.1%
Same as control; also 3 group sessions and monthly telephone calls from a peer counselor for 12 mo
7 peer counselors for 67 patients
Individual counseling visits with nutritionist at mo 1, 2, 3, and 416 hNone reported81% of participants attended at least 1 peer counselor session, 30% attended 2 sessions, and 19% attended 3 sessions
Average phone calls per participant: 9.7
Lorig et al,26 2008417United States: Spanish-speaking patients
Mean HbA1c 7.41%
6-wk program:
2.5 h weekly led by 2 peer leaders
2 peers per 10–15 patients
Usual care24 hRandom observationsNot reported
Lorig et al,25 2009345United States: white, non-Hispanic patients 67%
Mean HbA1C 6.72%
6-wk program:
2.5 h weekly led by 2 peer leaders
2 peers per 10–15 patients
Usual care24 hRandom observationsMean attendance of 4.9 of 6 sessions
Dale et al,32 2009187United Kingdom: white, non-Hispanic patients 96.65%
Mean HbA1c 8.55%
Peer supporter called participants after change in their diabetes care at days 7–10, 14–18, 28–35, 56–70, 120–150
1 peer called median of 10 patients
Usual care2-d training program developed for the studyNone reportedMean number of calls each patient received: 4.5 (range = 1–6 calls; SD, 2.2)
Cade et al,31 2009207United Kingdom: white, European-origin patients 95%
Mean HbA1C 7.4%
Peer educators delivered 2-h education sessions per week for 7 wk
5 peer educators for 86 participants
Usual careResidential training course provided by the Expert Patients Programme of the National Health ServiceNone reportedOf 110 participants in intervention group, 18 attended only 1 session and 22 attended all 7 sessions
63 participants attended final diabetes-specific session
Heisler et al,22 2010244United States: Male veterans, white non-Hispanic 82%
Mean HbA1c 7.97%
Peer partners encouraged to call weekly
Three optional 1.5-h face-to-face sessions at 1, 3, and 6 mo
Usual careInitial 1.5-h training in peer communication skillsInteractive voice response–facilitated telephone platform recorded call initiation, frequency, and duration90% of peer pairs had at least 1 conversation; average number of calls per pair per month was 2.4, 1.7, 1.4, 1.0, 0.9, 0.8 for 6 consecutive mo
Philis-Tsimikas et al,27 t2011207United States: Mexican Americans
Mean HbA1c 10.4%
Weekly 2.5-h education sessions by peer educators for 8 wkUsual care40 h of training, plus trainees cotaught 2 series of classes with their trainer and taught 2 series on their own, under observation by the trainerClasses were audio-recorded and reviewed using checklistsNot reported
Smith et al,34 2011388Republic of Ireland: Cluster randomized
50% population low income
Ireland general demographics 94.3% white non-Hispanic
Mean HbA1c 7.2%
9 peer supporter–facilitated sessions over 2 y; at mo 1, at mo 2, and every 3 mo thereafterUsual careTwo 3-h evening training sessions conducted by research teamsMeetings were recordedParticipants attended mean of 5 peer support meetings; 18% never attended a meeting
Long et al,24 201277United States: African American veterans
Mean HbA1c 9.85%
Weekly telephone calls by peer mentors; 34 mentors and 39 participantsUsual careSingle 1-h one-on-one training sessionNo supervisionFirst month, average of 4 calls/mo; by 6 mo, average of 2 calls/mo
Gagliardino et al,37 2013198Argentina: Hispanic, nonminority in country of residence
Mean HbA1c 7.2%
4 weekly peer educator sessions of 90–120 min initially; 1 at 6 mo followed by weekly calls for 6 mo then biweekly calls for 3 mo
Additional face-to-face visits among peers and their supportees were scheduled every second month if specific issues warranted
4 weekly sessions of 90–120 min initially; 1 at 6 mo by educators3-d intensive, structured, small group interactive courseDiabetes knowledge of participants tested with multiple-choice questionnaireNot reported
Siminerio et al,29 201368United States: white non-Hispanic ethnicity >80%
Mean HbA1c 8.65%
Same as control followed by monthly peer calls for 6 mo for diabetes self-management support6 wk of CDE diabetes self-management education intervention1-d peer training workshop for CDE with companion workbook-CDE then trained peers in 2-3–h small sessionsContact logs for communications; goal selections were trackedAverage of 5.03 calls per participant by peer supporter lasting approximately 25–30 min
Thom et al,30 2013299United States: Hispanic 46.65%, African American 31.25%; coded as predominantly Hispanic
Mean HbA1c 9.95%
Telephone contacts with peers at least twice a month and 2 or more in-person contacts in 6 mo
Coaches worked with median of 7 patients
Usual care36 h of training over 8 wk in either English or SpanishNot reportedMedian of 5 (range = 0–29) interactions with the peer health coach
123 patients (83%) had at least 1 interaction; most interactions (76.6%) were by telephone, and the remainder were in person
Chan et al,36 2014628China: Chinese speaking 100%
Mean HbA1c 8.2%
Same as control and peer supporter telephone calls: biweekly for 3 mo, then monthly for 3 mo, and then 1 call every other month for 6 mo; anticipated 15 min per callComprehensive assessment, personalized report, 2-h nurse-led empowerment class, follow-up primary care visit with repeated laboratory assessment and mailing of follow-up reportsFour 8-h training sessionsPeer supporter completed and mailed checklists to document discussion items, duration of each call, and relevant remarks every 3 moMedian of 20 calls per patient
Simmons et al,33 2015644England: Cluster randomized factorial design; white, non-Hispanic >90%
Mean HbA1c 7.3%
Peer-led group education sessions once a month for at least 5 mo and telephone/e-mail for 1:1 counselingUsual careMain training 14 h plus 3.5 h diabetes education sessionNot reported61.5% participants attended at least 1 education session; most participants had telephone or e-mail contacts with peers
Mean number of group attendances: 3.7
Safford et al,28 2015424United States: cluster randomized trial; African American >90%
Mean HbA1c 7.9%
Same as control and initial 45–60–min in-person or telephone get-to-know session with peer supporter followed by weekly calls for 2 mo followed by monthly calls for 8 mo1 h of group diabetes education class, 5-min counseling session, and diabetes report card12 h over 2 dContacts documented on forms and random contacts with intervention participantsMean number of contacts: 13.3 (SD, 8.1) 8.3% of participants had no contacts
Ayala et al,21 2015336United States: predominantly Hispanic
Mean HbA1c 8.7%
8 telephone or in-person contacts with peer supporter in first 6 mo, then as needed contacts in the last 6 mo; 92% of participants had telephone contacts
5–8 patients per peer leader
Usual care40–50 hContact logs maintained and tracked by peer leader coordinatorMedian number of contacts per participant: 4 (range = 1–24) 7% received no intervention
McGowan,35 2015361Canada: race/ethnicity not given
Mean HbA1c 7.19%
Two participant groups received 2 varied types of peer-led self-management programs with varying components: weekly meetings for 6 wkUsual care24 hSession attendance was loggedMean attendance for intervention group: 5 sessions
  • CDE = certified diabetes educator; HbA1c = hemoglobin A1c.