Meta-analysis of studies examining medication adherence, persistence, and discontinuation of oral antihyperglycemic agents in type 2 diabetes

Curr Med Res Opin. 2015;31(7):1283-96. doi: 10.1185/03007995.2015.1053048. Epub 2015 Jun 18.


Objective: To estimate overall rates of adherence, persistence, and discontinuation for patients with type 2 diabetes mellitus (T2DM) prescribed oral antihyperglycemic agents (OAHAs) by combining results of published studies.

Research design and methods: A systematic literature review was conducted to identify articles published in English over the last 10 years evaluating the use of OAHAs for the treatment of T2DM. Databases searched included PubMed/MEDLINE, EMBASE, and the Cochrane Library. Seventy studies reporting adherence, persistence or discontinuation were identified by two independent reviewers and 40 reported relevant endpoints for the analysis. Outcomes included: (1) mean adherence defined as the average medication possession ratio (MPR); (2) proportion of adherent patients (MPR ≥ 80%); (3) discontinuation; and (4) persistence. Adherence and persistence were reported in observational studies only. Discontinuation was examined separately in randomized controlled trials (RCTs) and observational studies. Meta-analyses were conducted using both fixed and random effects models. When meta-analysis was not appropriate for a given outcome, descriptive statistics were provided.

Results: The pooled mean MPR (95% confidence interval [CI]) was 75.3% (68.8%-81.7%; n = 13) and the proportion of adherent patients (95% CI) was 67.9% (59.6%-76.3%; n = 12). The discontinuation rate (95% CI) in RCTs was 31.8% (17.0%-46.7%; n = 7). Persistence and discontinuation were not assessed via meta-analysis for observational studies due to the limited number of available studies and differences in outcome definitions. In these studies, persistence estimates ranged from 41.0% to 81.1%, with a mean (95% CI) of 56.2% (46.1%-66.3%; n = 6), while discontinuation estimates ranged from 9.9% to 60.1%, with a mean (95% CI) of 31.4% (17.6%-45.3%; n = 6).

Limitations: Limitations include (1) the use of MPR as a proxy for adherence, (2) limited number of studies available, and (3) observed heterogeneity.

Conclusion: The results of the analysis demonstrate that medication adherence, persistence, and discontinuation rates are suboptimal in patients with T2DM prescribed OAHAs.

Keywords: Adherence; Discontinuation; Oral antihyperglycemic agents; Persistence; Type 2 diabetes.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Diabetes Mellitus, Type 2 / drug therapy*
  • Humans
  • Hypoglycemic Agents / therapeutic use*
  • Medication Adherence / statistics & numerical data*
  • Randomized Controlled Trials as Topic


  • Hypoglycemic Agents