Table 1

Characteristics of included studies in the meta-analysis

ReferenceStudy typeTreatment group (no participants)Adherence measuresThreshold for good adherencePrevalence of poor adherenceFollow-upLocation
Gibson et al., 2010 (32)Retrospective cohort study (administrative claims data)T2D on at least one OHA (96,734)PDCPDC ≥80%; PDC <80%25.5%24 monthsU.S.
Zhu et al., 2015 (39)Retrospective cohort study (Indiana Network for Patient Care)T2D on at least one OHA (24,067)PDCPDC ≥80%; PDC <80%90.6%12 monthsU.S.
Hong and Kang, 2011 (33)Retrospective cohort study (administrative claims data)T2D on at least one OHA (40,082)MPRMPR ≥80%; MPR <80%70.6%24 monthsSouth Korea
Ho et al., 2006 (38)Retrospective cohort study (Kaiser Permanente diabetes register)Diabetes including diet controlled, those on OHAs and insulin (11,532)PDC for OHAs, antihypertensives and statinsPDC ≥80%; PDC <80%21.3%16 monthsU.S.
Encinosa et al., 2010 (34)Retrospective cohort study (administrative claims data)T2D on at least one OHA (12,046)PDCPDC 100%; PDC <50%47.5%12 monthsU.S.
Jha et al., 2012 (35)Retrospective cohort study (administrative claims data–Medco database)Diabetes on at least one OHA but not insulin (81,807)MPRMPR ≥80%; MPR <80%24.8%12 monthsU.S.
Lau and Nau, 2004 (36)Retrospective cohort study (administrative claims data)T2D on at least one OHA but not insulin (900)MPRMPR ≥80%; MPR <80%28.8%12 monthsU.S.
White et al., 2004 (37)Retrospective cohort study (administrative claims data)Diabetes on at least one OHA (50,957)MPRMPR ≥75%; MPR <75%32.8%12 monthsU.S.
  • MPR, medication possession ratio; PDC, percentage of days covered; T2D, type 2 diabetes.