Prevalence of adherence to oral antidiabetic drugs in patients with type 2 diabetes: A systematic review and meta-analysis

INTRODUCTION

The treatment of type 2 diabetes requires multidimensional management, with medication adherence a crucial aspect of diabetes control. However, recent rigorous estimates of adherence to oral antidiabetic drugs (OAD) are lacking. The objective of this study is to determine the prevalence of adherence to OAD in type 2 diabetes patients.

METHODS

A systematic search was performed in PubMed, EMBASE, PsycINFO, and CINAHL from July 2013 to April 2023. Cross-sectional studies published in English were included if they met the following criteria: (1) reported the adherence to OAD using a validated measure; and (2) had a sample size of at least 385 patients with type 2 diabetes. The Joanna Briggs Institute critical appraisal for studies reporting prevalence data was used to assess the quality of the included studies. Pooled estimates of the prevalence of adherence to OAD were calculated as a percentage together with 95% confidence interval (95% CI) using a random-effect model. All analyses were conducted using STATA 17.0; PROSPERO (CRD42023414264).

RESULTS

Twenty-six studies involving a total of 69,366 patients met the selection criteria and were included in the meta-analysis. The overall estimated prevalence of adherence to OAD was 55.53% (95%CI: 44.22%-66.85%). Among the included studies, nine were deemed to be of high quality. A sensitivity analysis conducted using only the high-quality studies revealed a prevalence of adherence to OAD at 52.24% (95% CI: 39.63%-64.85%).

CONCLUSIONS

The overall prevalence of adherence to OAD was remarkably low among type 2 diabetes patients worldwide. Healthcare practitioners and policy makers should employ appropriate approaches to improve adherence to OAD.

Medication adherence to inflammatory bowel disease medications in Aotearoa New Zealand and correlation with health outcomes: A nationwide database analysis

AIMS

Inflammatory bowel disease (IBD) management entails long-term medication therapy. Worse disease outcomes and reduced quality of life might arise from poor medication adherence (MA). This study is the first to investigate patients with IBD's adherence across Aotearoa New Zealand and its relationship with disease outcomes.

METHODS

Dispensing claims data (Pharmaceutical Collection) were used to calculate (3- and 5-year) adherence, using daily polypharmacy possession ratio. Using hospitalization data (National Minimum Dataset), the relationship between adherence and the numbers of hospitalizations and corticosteroid dispensings was investigated.

RESULTS

In total, 4654 patients (53% female; 55% Crohn's disease [CD], 45% ulcerative colitis [UC]; median age-at-first-dispensing, 43 years) and 3148 patients (54% female; 55% CD, 44% UC; median age-at-first-dispensing, 44 years) were in the 3- and 5-year cohorts, respectively. The 3- and 5-year cohorts had mean 4.6 and 4.2 IBD-related hospitalizations and 6.9 and 9.2 corticosteroid dispensings, respectively. Average adherence estimates were 77.4% (95% confidence interval: 76.9-78.0%) and 74.9% (95% confidence interval: 74.1-75.6%; 3 and 5 years), while 54% and 51% of patients, respectively, had good adherence (MA ≥ 80%). There was no correlation between adherence and the numbers of hospitalizations (Pearson's R = -.0007; P = .65 and R = -.04; P = .02 [3 and 5 years]) and corticosteroid dispensings (R = .08; P = <.0001 and R = .08; P = <.0001, respectively).

CONCLUSION

MA of Aotearoa New Zealand patients with IBD is moderately high but just over half of patients meet the adherent threshold. There was no correlation between adherence and hospitalizations or corticosteroid dispensings; hence, research into longitudinal adherence patterns and associated factors is needed.

A global systematic overview of socioeconomic factors associated with antidiabetic medication adherence in individuals with type 2 diabetes

BACKGROUND

Antidiabetic medication adherence is a key aspect for successful control of type 2 diabetes mellitus (T2DM). This systematic review aims to provide an overview of the associations between socioeconomic factors and antidiabetic medication adherence in individuals with T2DM.

METHODS

A study protocol was established using the PRISMA checklist. A primary literature search was conducted during March 2022, searching PubMed, Embase, Web of Science, as well as WorldCat and the Bielefeld Academic Search Engine. Studies were included if published between 1990 and 2022 and included individuals with T2DM. During primary screening, one reviewer screened titles and abstracts for eligibility, while in the secondary screening, two reviewers worked independently to extract the relevant data from the full-text articles.

RESULTS

A total of 15,128 studies were found in the primary search, and 102 were finally included in the review. Most studies found were cross-sectional (72) and many investigated multiple socioeconomic factors. Four subcategories of socioeconomic factors were identified: economic (70), social (74), ethnical/racial (19) and geographical (18). The majority of studies found an association with antidiabetic medication adherence for two specific factors, namely individuals' insurance status (10) and ethnicity or race (18). Other important factors were income and education.

CONCLUSIONS

A large heterogeneity between studies was observed, with many studies relying on subjective data from interviewed individuals with a potential for recall bias. Several socioeconomic groups influencing medication adherence were identified, suggesting potential areas of intervention for the improvement of diabetes treatment adherence and individuals' long-term well-being.

Adherence to Oral Antidiabetic Drugs in Patients with Type 2 Diabetes: Systematic Review and Meta-Analysis

Poor adherence to oral antidiabetic drugs (OADs) in patients with type 2 diabetes (T2D) can lead to therapy failure and risk of complications. The aim of this study was to produce an adherence proportion to OADs and estimate the association between good adherence and good glycemic control in patients with T2D. We searched in MEDLINE, Scopus, and CENTRAL databases to find observational studies on therapeutic adherence in OAD users. We calculated the proportion of adherent patients to the total number of participants for each study and pooled study-specific adherence proportions using random effect models with Freeman-Tukey transformation. We also calculated the odds ratio (OR) of having good glycemic control and good adherence and pooled study-specific OR with the generic inverse variance method. A total of 156 studies (10,041,928 patients) were included in the systematic review and meta-analysis. The pooled proportion of adherent patients was 54% (95% confidence interval, CI: 51-58%). We observed a significant association between good glycemic control and good adherence (OR: 1.33; 95% CI: 1.17-1.51). This study demonstrated that adherence to OADs in patients with T2D is sub-optimal. Improving therapeutic adherence through health-promoting programs and prescription of personalized therapies could be an effective strategy to reduce the risk of complications.

Ethnic disparities in medication adherence? A systematic review examining the association between ethnicity and antidiabetic medication adherence

OBJECTIVES

Adherence to prescribed medication is an essential component of diabetes management to obtain optimal outcomes. Understanding the relationship between medication adherence and ethnicity is key to optimising treatment for all people with different chronic illnesses, including those with diabetes. The aim of this review is to examine whether the adherence to antidiabetic medications differed by ethnicity among people with diabetes.

METHODS

A systematic review was conducted of studies reporting adherence to antidiabetic medication amongst people from different ethnic groups. MEDLINE, Embase, CINAHL, and PsycINFO were searched from their inception to June 2022 for quantitative studies with a specific focus on studies assessing adherence to antidiabetic medications (PROSPERO: CRD42021278392). The Joanna Briggs Institute critical appraisal checklist and a second checklist designed for studies using retrospective databases were used to assess study quality. A narrative synthesis approach was used to summarize the results based on the medication adherence measures.

RESULTS

Of 17,410 citations screened, 41 studies that included observational retrospective database research and cross-sectional studies were selected, each of which involved diverse ethnic groups from different settings. This review identified a difference in the adherence to antidiabetic medications by ethnicity in 38 studies, despite adjustment for several confounding variables that may otherwise explain these differences.

CONCLUSION

This review revealed that adherence to antidiabetic medication differed by ethnicity. Further research is needed to explore the ethnicity-related factors that may provide an explanation for these disparities.

Māori, pharmacists, and medicines adherence – A mixed methods study exploring indigenous experiences of taking medicines ‘as prescribed’ and mechanisms of support

Background

Objectives

Methods

Results

Conclusions

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Māori experiences of medicines adherence are diverse.

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Pharmacists can support Māori medicines adherence in a variety of practical ways.

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Indigenous-led research promotes discourse reflective of Indigenous experience.

Metformin adherence in patients with type 2 diabetes and its association with glycated haemoglobin levels

INTRODUCTION Metformin is the initial medication of choice for most patients with type 2 diabetes. Non-adherence results in poorer glycaemic control and increased risk of complications. AIM The aim of this study was to characterise metformin adherence and association with glycated haemoglobin (HbA1c) levels in a cohort of patients with type 2 diabetes. METHODS Prescription and dispensing data were used for this study. Primary care clinical and demographic data were collected from 10 general practices (October 2016-March 2018) and linked to pharmaceutical dispensing information. Metformin adherence was initially measured by calculating the proportion of patients who had optimal medication cover for at least 80% of days (defined as a medication possession ratio (MPR) of ≥0.8), calculated using dispensing data. Prescription adherence was assessed by comparing prescription and dispensing data. The association between non-adherence (MPR <0.8) and HbA1c levels was also assessed. RESULTS Of the 1595 patients with ≥2 metformin prescriptions, the mean MPR was 0.87. Fewer Māori had an MPR ≥0.8 than New Zealand European (63.8% vs. 81.2%). Similarly, Māori received fewer metformin prescriptions (P=0.02), although prescription adherence did not differ by ethnicity. Prescription adherence was lower in younger patients (P=0.002). Mean HbA1c levels were reduced by 4.8 and 5.0mmol/mol, respectively, in all and Māori patients with an MPR ≥0.8. Total prescription adherence reduced HbA1c by 3.2mmol/mol (all P<0.01). DISCUSSION Ethnic disparity exists for metformin prescribing, leading to an overall reduction in metformin coverage for Māori patients. This needs to be explored further, including understanding whether this is a patient preference or health system issue.