Systematic review of adherence rates by medication class in type 2 diabetes: a study protocol

Multilevel Analysis of the Relationship Between Prescribing Institutions and Medication Adherence Among Patients With Hypertension and Diabetes in Korea

OBJECTIVES

This study investigated the relationship between prescribing institutions and medication adherence among patients newly diagnosed with hypertension and diabetes.

METHODS

This study investigated patients with new prescriptions for hypertension and diabetes in Korea in 2019 with using data collected from general health screenings. A multilevel logistic regression model was applied to explore the relationship between patients' first prescribing institution and their medication adherence, defined as a medication possession ratio (MPR) over 80%.

RESULTS

The overall adherence rates were 53.7% and 56.0% among patients with hypertension and diabetes, respectively. The intraclass correlation coefficients were 13.2% for hypertension and 13.8% for diabetes (p<0.001), implying that the first prescribing institution had a significant role in medication adherence. With clinics as the reference group, all other types of hospitals showed an odds ratio (OR) less than 1.00, with the lowest for tertiary hospitals (OR, 0.30 for hypertension; 0.45 for diabetes), and the next lowest in health screening specialized clinics (OR, 0.51 for hypertension; 0.46 for diabetes). Among individual-level variables, female sex, older age, higher insurance premium level, and residing in cities were positively associated with adherence in both the hypertension and diabetes samples.

CONCLUSIONS

This study showed that the prescribing institution had a significant relationship with medication adherence. When the first prescribing institution was a clinic, newly diagnosed patients were more likely to adhere to their medication. These results highlight the important role played by primary care institutions in managing mild chronic diseases.

2023 Clinical Practice Guidelines for Diabetes Mellitus of the Korean Diabetes Association

In May 2023, the Committee of Clinical Practice Guidelines of the Korean Diabetes Association published the revised clinical practice guidelines for Korean adults with diabetes and prediabetes. We incorporated the latest clinical research findings through a comprehensive systematic literature review and applied them in a manner suitable for the Korean population. These guidelines are designed for all healthcare providers nationwide, including physicians, diabetes experts, and certified diabetes educators who manage patients with diabetes or individuals at risk of developing diabetes. Based on recent changes in international guidelines and the results of a Korean epidemiological study, the recommended age for diabetes screening has been lowered. In collaboration with the relevant Korean medical societies, recently revised guidelines for managing hypertension and dyslipidemia in patients with diabetes have been incorporated into this guideline. An abridgment containing practical information on patient education and systematic management in the clinic was published separately.

Socio-personal factors affecting adherence to treatment in patients with type 2 diabetes: A systematic review and meta-analysis

PURPOSE

The purpose of study was to identify the socio-personal factors affecting adherence to the treatment of patients with type 2 diabetes.

METHODS

Cross-sectional articles were extracted from databases such as Web of Science, PubMed, Elsevier. A meta-analysis was performed using integrated odds ratios (OR) and 95% confidence interval (CIs) for age, BMI, depression, educational level, gender, employment status, marital status, smoking status. STATA 12.0 was used to estimate pooled RR in definite subgroups. The quality of the studies included was evaluated using the STROBE checklist.

RESULTS

Thirty-one studies out of 7407 extracted articles were finally selected for the meta-analysis. The results showed that younger people had a 17% higher risk than older people, smokers had a 22% higher risk than non-smokers, and the employed had a 15% higher risk of non-adherence to treatment.

CONCLUSION

In conclusion, older age, smoking and employment can lead to non-adherence to T2D treatment. Interventions are suggested to be made besides common health care considering the socio-personal features on type 2 diabetes patients' treatment adherence.

Barriers against the use of an optimal dose of metformin among patients with T2DM in Thi-Qar province, Iraq

Diabetes mellitus is a disease with a high burden and prevalence and serious complications. Glycemic control is vital in delaying or preventing complications. Although many people do not take optimal doses, metformin is a cornerstone in managing type 2 diabetes mellitus (T2DM) in all guidelines. This study determined the barriers interfering with optimal metformin dosage. A cross-sectional study was conducted in Thi-Qar Specialized, Diabetes, Endocrine and Metabolism Center (TDEMC) at Thi-Qar, southern Iraq, from January 2019 to January 2020. 475 patients (274 females and 201 males) were included, and examination and lab investigations were performed. Only 22 (4.6%) patients took the optimal dose with no differences between gender. Of those who took metformin, 255 (74%) took it as a regular pill, 79 (23%) as a combined form with sulfonylureas (SUs), while only 10 (0.3%) took combined pills with Dipeptidyl Peptidase-4 inhibitors (DPP4i). 188 patients (65%) took metformin with meals, 84 (29%) before meals, and 19 (6%) after meals. Ignorance caused poor adherence to optimal dose in 165 patients (38.6%), neglect in 75 (17.6%), the cost in 5 (1.2%), 11 patients (2.6%) thought they did not need metformin, 37(8.7%) and 12 (2.8%) blame side effects and shortage of supply from public health care clinics (PHCC) as a cause, respectively. The rest of the patients had more than one cause. The most common side effects were abdominal pain and bloating, 5.9% and 3.8%, respectively. Other side effects were diarrhea in 0.2%, and 7.8% of patients developed more than one side effect. Ignorance and neglect were major obstacles, so educating doctors and patients and supplying the patient with optimal doses through PHCC may overcome the problem.

Anti-Hyperglycemic Medication Adherence and Health Services Utilization in People with Diabetes: A Longitudinal Study of Alberta's Tomorrow Project

BACKGROUND

Little is known about the long-term (>2 years) relationship between the time-varying drug adherence and healthcare utilization for patients with diabetes.

OBJECTIVE

To characterize the relationship between time-varying anti-hyperglycemic medication adherence and healthcare utilization in patients with diabetes, using data from Alberta's Tomorrow Project, a population-based cohort study in Alberta, Canada.

METHODS

Incident cases of diabetes with at least 24 months of follow-up were included in the study. Anti-hyperglycemic drug adherence was measured by proportion of days covered (PDC) in the past 12 months for each year after diagnosis. The rate of healthcare utilization was assessed for the subsequent 12 months, 36 months and 60 months. A time-varying, negative binomial generalized estimating equation model was used to examine the association between medication adherence and healthcare utilization.

RESULTS

Among 2155 incident cases of diabetes, average age at diagnosis was 59.6±9.3, 51.0% were female and average duration of follow-up was 7.3±3.7 (range, 2.0-16.2) years. The proportion of patients taking anti-hyperglycemic medications was 47.6% during the first year of diagnosis, which increased to 77.3% by the end of follow-up. Compared to adherent patients (PDC≥0.8), non-adherent patients (PDC<0.8) had substantially higher rate of all-cause hospitalization [incident rate ratio, IRR=1.48 (1.22-1.79), ED visits [1.30 (1.15-1.47)] and GP visits [1.17 (1.08-1.27)] in the subsequent 12 months. However, these associations became weaker with longer follow-up [eg, IRR=1.18 (0.98-1.39) and 1.05 (0.94-1.18) for all-cause hospitalization in the subsequent 36 and 60 months, respectively].

CONCLUSION

Poor adherence among diabetic patients was associated with substantially higher rate of healthcare utilization in the short term (eg, 12 months); however, this association weakened over a longer period (eg, 36-60 months).

A study on the impact of poor medication adherence on health status and medical expense for diabetes mellitus patients in Taiwan: A longitudinal panel data analysis

Medication adherence plays an important role in disease management, especially for diabetes. The aim of this study was to examine the impacts of demographic characteristics on medication nonadherence and the impacts of nonadherence on both health status and medical expenses for diabetic patients in Taiwan.A total of 1 million diabetes mellitus patients were randomly selected from the National Health Insurance Research Database between January 1, 2000 and December 31, 2004. All records with missing values and those for participants under 18 years of age were then deleted. Because many patients had multiple clinical visit records, all records within the same calendar year were summarized into 1 single record for each person. This pre-processing resulted in 14,602 total patients with a combined 73,010 records over the course of 5 years. Generalized estimating equation models were then constructed to investigate the effects of demographic characteristics on medication nonadherence and the effects of nonadherence on patient health status and medical expenses. The demographic characteristics examined for each patient include gender, age, residential area, and socioeconomic status.Our analysis of how demographic variables impacted nonadherence revealed that elderly patients exhibited better overall medication adherence, but that male patients exhibited poorer medication adherence than female patients. Next, our analysis of how nonadherence impacted health status revealed that patients who exhibited medication nonadherence had poorer health status than patients with proper medication adherence. Finally, our analysis of how nonadherence impacted medical expenses revealed that patients who exhibited medication nonadherence incurred more medical expenses than those who exhibited proper medication adherence.This study's empirical results corroborate the general relationships expressed in the current literature regarding medication nonadherence. However, this study's results were statistically more reliable and revealed the precise impact on health status in terms of the Charlson comorbidity index and increased annual medical expenses. This indicates the need to improve patient attitudes toward medication adherence, which can have substantial effects both medically and economically.

Initial Therapy, Regimen Change, and Persistence in a Spanish Cohort of Newly Treated Type 2 Diabetes Patients: A Retrospective, Observational Study Using Real-World Data

The World Health Organization considers the non-adherence to medication a significant issue with global impact, especially in chronic conditions such as type 2 diabetes. We aim to study antidiabetic treatment initiation, add-on, treatment switching, and medication persistence. We conducted an observational study on 4247 individuals initiating antidiabetic treatment between 2013 and 2014 in the EpiChron Cohort (Spain). We used Cox regression models to estimate the likelihood of non-persistence after a one-year follow-up, expressed as hazard ratios (HRs). Metformin was the most frequently used first-line antidiabetic (80% of cases); combination treatment was the second most common treatment in adults aged 40–79 years, while dipeptidyl peptidase-4 inhibitors were the second most common in individuals in their 80s and over, and in patients with renal disease. Individuals initiated on metformin were less likely to present addition and switching events compared with any other antidiabetic. Almost 70% of individuals initiated on monotherapy were persistent. Subjects aged 40 and over (HR 0.53–0.63), living in rural (HR 0.79) or more deprived areas (HR 0.77–0.82), or receiving polypharmacy (HR 0.84), were less likely to show discontinuation. Our findings could help identify the population at risk of discontinuation, and offer them closer monitoring for proper integrated management to improve prognosis and health outcomes.

Management of hyperglycaemia in type 2 diabetes, 2018. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association and the European Association for the Study of Diabetes convened a panel to update the prior position statements, published in 2012 and 2015, on the management of type 2 diabetes in adults. A systematic evaluation of the literature since 2014 informed new recommendations. These include additional focus on lifestyle management and diabetes self-management education and support. For those with obesity, efforts targeting weight loss, including lifestyle, medication and surgical interventions, are recommended. With regards to medication management, for patients with clinical cardiovascular disease, a sodium-glucose cotransporter-2 (SGLT2) inhibitor or a glucagon-like peptide-1 (GLP-1) receptor agonist with proven cardiovascular benefit is recommended. For patients with chronic kidney disease or clinical heart failure and atherosclerotic cardiovascular disease, an SGLT2 inhibitor with proven benefit is recommended. GLP-1 receptor agonists are generally recommended as the first injectable medication.

Persistence of oral antidiabetic treatment for type 2 diabetes characterized by drug class, patient characteristics and severity of renal impairment: A Japanese database analysis

AIM

To evaluate the persistence with oral antidiabetic drug (OAD) treatment characterized by drug class, patient characteristics and severity of renal impairment (RI) in patients with type 2 diabetes (T2DM) in Japan.

MATERIALS AND METHODS

This retrospective, observational study extracted data from a large-scale hospital database (April 2008 to September 2016). Patients with T2DM aged ≥40 years on the day of their first prescription (index date) of any OAD (biguanides [BGs], thiazolidinediones [TZDs], sulphonylureas [SUs], glinides, dipeptidyl peptidase-4 [DPP-4] inhibitors, or α-glucosidase inhibitors [α-GIs]) available between January 1, 2014 and September 30, 2016 were identified. Sodium-glucose co-transporter-2 inhibitors were not available at study initiation. Treatment persistence was assessed by Kaplan-Meier survival curves. Patients were also categorized by RI status using estimated glomerular filtration rate: ≥90 mL/min/1.73 m2 (G1); 60 to <90 mL/min/1.73 m2 (G2); 30 to <60 mL/min/1.73 m2 (G3); and <30 mL/min/1.73 m2 (G4+).

RESULTS

We identified 206 406 index dates from 162 116 eligible patients. The largest number of index dates (91634) was observed for DPP-4 inhibitors, followed by BGs, SUs, α-GIs, glinides and TZDs. Treatment persistence was longest for DPP-4 inhibitors (median 17.0 months, 95% confidence interval [CI] 16.4-17.5) and BGs (median 17.3 months, 95% CI 16.6-18.2), and shortest for α-GIs (median 5.6 months, 95% CI 5.4-5.9) and SUs (median 4.3 months, 95% CI 4.2-4.6). Persistence was longest with DPP-4 inhibitors at all RI stages (G1-G4+), followed by BGs at stages G1/G2.

CONCLUSIONS

The longest OAD persistence was observed for BGs and DPP-4 inhibitors at RI stages G1/G2, and for DPP-4 inhibitors at RI stages G3/G4+.

Management of Hyperglycemia in Type 2 Diabetes, 2018. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The American Diabetes Association and the European Association for the Study of Diabetes convened a panel to update the prior position statements, published in 2012 and 2015, on the management of type 2 diabetes in adults. A systematic evaluation of the literature since 2014 informed new recommendations. These include additional focus on lifestyle management and diabetes self-management education and support. For those with obesity, efforts targeting weight loss, including lifestyle, medication, and surgical interventions, are recommended. With regards to medication management, for patients with clinical cardiovascular disease, a sodium-glucose cotransporter 2 (SGLT2) inhibitor or a glucagon-like peptide 1 (GLP-1) receptor agonist with proven cardiovascular benefit is recommended. For patients with chronic kidney disease or clinical heart failure and atherosclerotic cardiovascular disease, an SGLT2 inhibitor with proven benefit is recommended. GLP-1 receptor agonists are generally recommended as the first injectable medication.

The efficacy and safety of once-weekly DPP-4 inhibitor omarigliptin in patients with type 2 diabetes mellitus: A systemic review and meta-analysis

BACKGROUND

The efficacy and safety of once-weekly dipeptidyl peptidase-4 inhibitor (DPP-4i) omarigliptin as monotherapy or add on to other antihyperglycemic agents (AHAs) in patients with type 2 diabetes mellitus (T2DM) is unclear.

METHODS

PubMed, EMBASE, Cochrane library, and ClinicalTrials.gov were searched from the inception to January 24, 2018. Randomized controlled trials comparing omarigliptin with placebo or other AHAs in T2DM patients were included in our meta-analysis. Risk ratio (RR) and mean difference (MD) were used to evaluate the outcomes.

RESULTS

Totally, 11 trials involving 8276 patients were satisfied with our inclusion criteria. Compared with control group, omarigliptin was associated with a significantly stronger reduction in hemoglobin A1c (HbA1c) (MD 0.38%, 95% confidence interval [CI] [0.18, 0.58], P = .0002) and fasting plasma glucose (MD 0.48 mmol/L, 95% CI [0.14 mmol/L, 0.82 mmol/L], P = .006). Omarigliptin increased the number of participants who achieved HbA1c < 7.0% compared with control group (RR 2.03, 95% CI [1.38, 2.98], P = .0003). No significant difference was found in the aspect of adverse events (RR 1.00, 95% CI [0.97, 1.03], P = .99), serious adverse events (RR 1.02, 95% CI [0.91, 1.13], P = .75), hypoglycemic events (RR 0.86, 95% CI [0.48, 1.54], P = .61) between omarigliptin and control group. Omarigliptin has a homologous efficacy and safety background to other AHAs according to the results of subgroup analysis.

CONCLUSIONS

This review revealed that omarigliptin had a favorable efficacy and safety as monotherapy or add on to other AHAs in treating T2DM patients. It is a superior choice for T2DM patients who have a poor adherence to daily AHAs.

Comparison of medication adherence and persistence in type 2 diabetes: A systematic review and meta-analysis

Limited medication adherence and persistence with treatment are barriers to successful management of type 2 diabetes (T2D). We searched MEDLINE, EMBASE, the Cochrane Library, the Register of Controlled Trials, PsychINFO and CINAHL for observational and interventional studies that compared the adherence or persistence associated with 2 or more glucose-lowering medications in people with T2D. Where 5 or more studies provided the same comparison, a random-effects meta-analysis was performed, reporting mean difference (MD) or odds ratio (OR) for adherence or persistence, depending on the pooled study outcomes. We included a total of 48 studies. Compared with metformin, adherence (%) was better for sulphonylureas (5 studies; MD 10.6%, 95% confidence interval [CI] 6.5-14.7) and thiazolidinediones (TZDs; 6 studies; MD 11.3%, 95% CI 2.7%-20.0%). Adherence to TZDs was marginally better than adherence to sulphonylureas (5 studies; MD 1.5%, 95% CI 0.1-2.9). Dipeptidyl peptidase-4 inhibitors had better adherence than sulphonylureas and TZDs. Glucagon-like peptide-1 receptor agonists had higher rates of discontinuation than long-acting analogue insulins (6 studies; OR 1.95; 95% CI 1.17-3.27). Long-acting insulin analogues had better persistence than human insulins (5 studies; MD 43.1 days; 95% CI 22.0-64.2). The methods used to define adherence and persistence were highly variable.

Assessing oral medication adherence among patients with type 2 diabetes mellitus treated with polytherapy in a developed Asian community: a cross-sectional study

OBJECTIVES

The disease burden of type 2 diabetes mellitus (T2DM) is rising due to suboptimal glycaemic control leading to vascular complications. Medication adherence (MA) directly influences glycaemic control and clinical consequences. This study aimed to assess the MA of patients with T2DM and identify associated factors.

DESIGN

Analysis of data from a cross-sectional survey and electronic medical records.

SETTING

Primary care outpatient clinic in Singapore.

PARTICIPANTS

Adult patients with T2DM.

MAIN OUTCOME MEASURES

MA to each prescribed oral hypoglycaemic agent (OHA) was measured using the five-question Medication Adherence Report Scale (MARS-5). Low MA is defined as a MARS-R score of <25. Demographic data, clinical characteristics and investigation results were collected to identify factors that are associated with low MA.

RESULTS

The study population comprised 382 patients with a slight female predominance (53.4%) and a mean±SD age of 62.0±10.4 years. 57.1% of the patients had low MA to at least one OHA. Univariate analysis showed that patients who were younger, of Chinese ethnicity, married or widowed, self-administering their medications or taking fewer (four or less) daily medications tended to have low MA to OHA. Logistic regression revealed that younger age (OR 0.97; 95% CI 0.95 to0.99), Chinese ethnicity (OR 2.80; 95% CI 1.53 to5.15) and poorer glycaemic control (HbA1c level) (OR 1.27; 95% CI 1.06 to1.51) were associated with low MA to OHA.

CONCLUSIONS

Younger patients with T2DM and of Chinese ethnicity were susceptible to low MA to OHA, which was associated with poorer glycaemic control. Polytherapy was not associated with low MA.

Adherence and persistence in patients with type 2 diabetes mellitus newly initiating canagliflozin, dapagliflozin, dpp-4s, or glp-1s in the United States

OBJECTIVE

Sodium-glucose co-transporter 2 inhibitors were first approved in the US in 2013; therefore, real-world (RW) studies describing outcomes are limited. This retrospective study evaluated adherence and persistence among patients initiating canagliflozin (CANA), dapagliflozin (DAPA), GLP-1 agonists (GLP-1s), and DPP-4 inhibitors (DPP-4s) over a 12-month follow-up from a US managed care perspective.

METHODS

Patients newly initiating CANA, DAPA, GLP-1s, or DPP-4s from February 1, 2014-June 30, 2014 were identified from the QuintilesIMS PharMetrics Plus Database. The first fill defined the index date/drug. Patients were required to have a T2DM diagnosis (ICD-9-CM 250.x[0,2]) and ≥12 months of continuous enrollment pre- and post-index (follow-up). Main outcome measures were adherence (proportion of days covered, PDC; medication possession ratio, MPR) and persistence on index therapy. PDC or MPR ≥0.80 was considered adherent. Patients were considered persistent until evidence of discontinuation (gap ≥90 days between two subsequent index therapy prescriptions). Kaplan-Meier (KM) analysis assessed time to discontinuation, while a Cox proportional hazards model (PHM) evaluated risk of discontinuation. Logistic regression models evaluated the likelihood of non-adherence.

RESULTS

The final sample consisted of 23,702 patients (6,546 CANA, 3,087 DAPA, 6,273 GLP-1s, and 7,796 DPP-4s; 56% male, and mean [SD] age = 55 [9.1] years). Mean PDC ranged from 0.56 (GLP-1), to 0.71 (CANA), with 33-56% adherent, respectively; MPR results were similar. Fifty-two per cent (GLP-1) to 68% (CANA) were persistent over the follow-up. CANA patients had the longest time to discontinuation. In regression analyses, compared to CANA 100 mg, DAPA, DPP-4, and GLP-1 patients had a significantly higher likelihood of non-adherence and a significantly higher risk of discontinuation. CANA 300 mg patients had a significantly lower likelihood of non-adherence and a significantly lower risk of discontinuation compared to CANA 100 mg.

CONCLUSIONS

Adherence and persistence were significantly better with CANA (100 mg and 300 mg) compared to DAPA, GLP-1s, and DPP-4s in the RW setting.

Patterns and Predictors of Adherence to Statin Therapy Among Older Patients: Protocol for a Systematic Review

Background

The benefits of statin therapy are significantly compromised by noncompliance. Although elderly patients may have particular challenges with medication adherence and persistence, previous reviews on statin adherence have not focused on this population. Additionally, comparisons of adherence and persistence specific to statin indication (primary or secondary prevention) have not been thoroughly explored.

Objective

We aim to assess the extent of, and factors associated with, adherence and persistence to statin therapy among older populations (aged ≥65 years).

Methods

A systematic review will be undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Searches will be performed using multiple electronic databases (Ovid MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects, and the National Health Service Economic Evaluation Database) to identify relevant randomized trials and observational studies that evaluated statin adherence and/or persistence as an outcome. Eligible studies will include those involving community-living or outpatient elderly individuals. The methodological quality of randomized controlled trials (RCTs) will be assessed via the Joanna Briggs Institute’s critical appraisal checklist for RCTs, and the quality assessment of observational studies will be undertaken using a set of questions formulated with resort to the National Institute of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. When possible, meta-analyses will be conducted using random-effect modeling and generic inverse variance analyses for adjusted-effect estimates. Heterogeneity across studies will be quantified using the I² statistic. The presence of publication bias will be assessed using funnel plots and Egger’s regression tests. A leave-one-out sensitivity analysis will also be conducted to assess the impact of individual study results on pooled estimates. To explore possible sources of heterogeneity across studies, subgroup analyses will be performed based on covariates such as study design, statin indication, country of study, and length of patient follow-up.

Results

The electronic database searches were completed in December 2016. Retrieved articles are currently being screened and the entire study is expected to be completed by June 2017.

Conclusions

This systematic review will provide further understanding of the patterns of, and barriers to, statin adherence and persistence among older patients. The findings will inform clinical practice and the design of appropriate interventions.

Trial Registration

PROSPERO CRD42016053191