Pharmacy-led Interventions to Improve Medication Adherence Among Adults with Diabetes: A Systematic Review and Meta-analysis

Background: Control of blood glucose and a reduced risk of complications are important treatment goals in diabetes. Medication non-adherence can influence the outcome of diabetes. Involvement of a pharmacist in diabetes care might help patients to achieve better treatment outcomes. Existing literature reviews have focused on a limited number of interventions and outcome measures, and have involved different healthcare professionals. None of the previous reviews have used a standardized effect size to compare the effects of different pharmacist-led interventions and different outcome measures.

Objective: To review pharmacist-led interventions to improve medication adherence in patients with diabetes and to assess the effectiveness of these interventions on medication adherence.

Methods: Six databases were systematically searched between March and September 2017 for randomized controlled trials: PubMed, Cochrane library, EMBASE, CINAHL, JSTOR, and Web of Science. The outcome measures used were: medication adherence, HbA1c, fasting plasma glucose (FPG), post-prandial blood glucose (PPG), or random blood glucose (RBG). Cohen's d, a standardized effect size, enabled a comparison of studies with different outcome measures. The Cochrane risk of bias tool was used to assess the quality of the studies.

Results: Fifty-nine studies were included in this review. Pharmacist-led interventions enhanced outcomes in patients with diabetes (standardized mean difference (SMD) -0.68; 95% CI -0.79, -0.58; p < 0.001). Sub-group analysis by intervention strategy, the type of intervention and outcome measures produced similar results. Further analysis showed that education, printed/digital material, training/group discussion, were more effective than other interventions.

Conclusion: This finding supports the role of the pharmacist in diabetes care to enhance medication adherence.