Methodological issues in the assessment of diabetes treatment adherence

Self-reported and measured adherence to hepatitis C direct-acting antiviral therapy and sustained virologic response among people who inject drugs: The HERO study

BACKGROUND

Objective adherence measures, such as electronic blister pack (BP), for direct-acting antivirals (DAAs) for hepatitis C virus (HCV) treatment have high accuracy, but their use is limited in real practice settings. We examined the association of self-reported adherence using a visual analogue scale (VAS) with objective BP adherence and sustained virologic response (SVR) among people who inject drugs.

METHODS

We conducted secondary analyses using a subset of participants (N = 493) from the per-protocol sample of the HERO study, a pragmatic randomized trial of HCV treatment interventions that used both VAS and BP to measure adherence to a 12-week sofosbuvir/velpatasvir DAA regimen. Multivariable mixed-effects regression models tested the association of self-report adherence level with longitudinal weekly objective adherence. Multivariable logistic regression tested the association of self-report adherence with SVR.

RESULTS

The average VAS and BP adherences were 95.1 % (SD = 8.9 %) and 76.0 % (16.0 %), respectively, and the proportion of the participants achieving SVR was 92.9 %. The estimated adjusted mean objective adherence was significantly different (-16 %; 95 % CI: -22 %, -11 %, p < .001) between participants with 100 % and <80 % VAS adherence. The likelihood of SVR was significantly lower for those with <80 % VAS adherence [adjusted OR = 0.07; 95 % CI: 0.02, 0.24; p < .001] compared to those with 100 %.

CONCLUSION

Self-reported adherence overestimated objective adherence. However, higher self-report adherence was significantly associated with higher objective adherence. Also, self-reported adherence ≥80 % was significantly associated with SVR. Thus, the self-report measure has utility as a monitoring tool for adherence during DAA treatment.

A Three-Step Data-Driven Methodology to Assess Adherence to Basal Insulin Therapy in Patients With Insulin-Treated Type 2 Diabetes

BACKGROUND

While health care providers (HCPs) are generally aware of the challenges concerning insulin adherence in adults with insulin-treated type 2 diabetes (T2D), data guiding identification of insulin nonadherence and understanding of injection patterns have been limited. Hence, the aim of this study was to examine detailed injection data and provide methods for assessing different aspects of basal insulin adherence.

METHOD

Basal insulin data recorded by a connected insulin pen and prescribed doses were collected from 103 insulin-treated patients (aged ≥18 years) with T2D from an ongoing clinical trial (NCT04981808). We categorized the data and analyzed distributions of correct doses, increased doses, reduced doses, and missed doses to quantify adherence. We developed a three-step model evaluating three aspects of adherence (overall adherence, adherence distribution, and dose deviation) offering HCPs a comprehensive assessment approach.

RESULTS

We used data from a connected insulin pen to exemplify the use of the three-step model to evaluate overall, adherence, adherence distribution, and dose deviation using patient cases.

CONCLUSION

The methodology provides HCPs with detailed access to previously limited clinical data on insulin administration, making it possible to identify specific nonadherence behavior which will guide patient-HCP discussions and potentially provide valuable insights for tailoring the most appropriate forms of support.

Quantification of insulin adherence in adults with insulin-treated type 2 diabetes: A systematic review

AIMS

This systematic review aims to identify current methods used for the assessment of insulin adherence in adults with insulin-treated type 2 diabetes. The primary goal is to offer recommendations for clinical practice to improve quantification of adherence.

METHODS

The review was conducted in accordance with PRISMA 2020 and registered at PROSPERO (CRD42022334134). PubMed, Embase, CINAHL, and PsycINFO were searched on 15 November 2022 and included three blocks: Type 2 diabetes, insulin, and adherence. We considered primary full-text studies describing an assessment method and a threshold for assessment of insulin adherence in adults with insulin-treated type 2 diabetes.

RESULTS

A final sample of 50 studies were included. Identified methods fell into four categories: self-report, pharmacy claims, inulin count, and data from an insulin pen device. Commonly reported methods included: The Morisky Medication Adherence Scale, the (adjusted) Medication Possession Ratio, and the Proportions of Days Covered. A threshold of <80% was used to define non-adherence in nearly half of the studies. Yet, several thresholds were reported.

CONCLUSIONS

Most available methods for assessing insulin adherence in adults with insulin-treated type 2 diabetes are severely limited in providing in-depth insights into timing, dosing size, injection patterns, and adherence behavior. However, recognizing diverse types of non-adherence is crucial, as they denote unique behavioral entities requiring targeted intervention. Employing insulin injection data (e.g., from a smart insulin pen cap) to underlie an assessment method is a potential new approach to objectively assess insulin timing and dosing adherence in adults with insulin-treated type 2 diabetes.

SPUR: A Patient-Reported Medication Adherence Model as a Predictor of Admission and Early Readmission in Patients Living with Type 2 Diabetes

PURPOSE

Poor medication adherence (MA) is linked to an increased likelihood of hospital admission. Early interventions to address MA may reduce this risk and associated health-care costs. This study aimed to evaluate a holistic Patient Reported Outcome Measure (PROM) of MA, known as SPUR, as a predictor of general admission and early readmission in patients living with Type 2 Diabetes.

PATIENTS AND METHODS

An observational study design was used to assess data collected over a 12-month period including 6-month retrospective and 6-month prospective monitoring of the number of admissions and early readmissions (admissions occurring within 30 days of discharge) across the cohort. Patients (n = 200) were recruited from a large South London NHS Trust. Covariates of interest included: age, ethnicity, gender, level of education, income, the number of medicines and medical conditions, and a Covid-19 diagnosis. A Poisson or negative binomial model was employed for count outcomes, with the exponentiated coefficient indicating incident ratios (IR) [95% CI]. For binary outcomes (Coefficient, [95% CI]), a logistic regression model was developed.

RESULTS

Higher SPUR scores (increased adherence) were significantly associated with a lower number of admissions (IR = 0.98, [0.96, 1.00]). The number of medical conditions (IR = 1.07, [1.01, 1.13]), age ≥80 years (IR = 5.18, [1.01, 26.55]), a positive Covid-19 diagnosis during follow-up (IR = 1.83, [1.11, 3.02]) and GCSE education (IR = 2.11, [1.15,3.87]) were factors associated with a greater risk of admission. When modelled as a binary variable, only the SPUR score (-0.051, [-0.094, -0.007]) was significantly predictive of an early readmission, with patients reporting higher SPUR scores being less likely to experience an early readmission.

CONCLUSION

Higher levels of MA, as determined by SPUR, were significantly associated with a lower risk of general admissions and early readmissions among patients living with Type 2 Diabetes.

Development and validation of a new non-disease-specific survey tool to assess self-reported adherence to medication

Background: Patients' non-adherence to medication affects both patients themselves and healthcare systems. Consequences include higher mortality, worsening of disease, patient injuries, and increased healthcare costs. Many existing survey tools for assessing adherence are linked to specific diseases and assessing medication-taking behavior or identifying barriers or beliefs. This study aimed to develop and validate a new non-disease-specific survey tool to assess self-reported medication-taking behavior, barriers, and beliefs in order to quantify the causes of non-adherence and measure adherence. Methods: The survey tool was developed after literature searches and pilot testing. Validation was conducted by assessing the psychometric properties of content, construct, reliability, and feasibility. Content validity was assessed by subject matter experts and construct validity by performing exploratory factor analysis. Reliability assessment was performed by calculating internal consistency, Cronbach's alpha and test/retest reliability, intraclass correlation coefficient (ICC), and standard error of measurement (SEm). A receiver operating characteristic (ROC) curve and the Lui method were used to calculate the statistical cut-off score for good versus poor adherence. Survey responses from Norwegian medication users over 18 years recruited via social media were used for the factor analysis and Cronbach's alpha. Results: The final survey tool contains 37 causes of non-adherence connected to medication-taking behavior and barriers to adherence and beliefs associated with adherence. The overall result for all 37 items demonstrated reliable internal consistency, Cronbach's alpha = 0.91. The factor analysis identified ten latent variables for 29 items, explaining 61.7% of the variance. Seven of the latent variables showed reliable internal consistency: medication fear and lack of effect, conditional practical issues, pregnancy/breastfeeding, information issues, needlessness, lifestyle, and avoiding stigmatization (Cronbach's alpha = 0.72-0.86). Shortage showed low internal consistency (Cronbach's alpha = 0.59). Impact issues and personal practical issues showed poor internal consistency (Cronbach's alpha = 0.51 and 0.48, respectively). The test/retest reliability ICC = 0.89 and SEm = 1.11, indicating good reliability. The statistical cut-off score for good versus poor adherence was 10, but the clinical cut-off score was found to be 2. Conclusion: This survey tool, OMAS-37 (OsloMet Adherence to medication Survey tool, 37 items), demonstrated to be a valid and reliable instrument for assessing adherence. Further studies will examine the ability of the tool for measuring adherence enhancing effect following interventions.

Memory complaints moderate the concordance between self-report and electronically monitored adherence in adults with type 2 diabetes

AIMS

We examined the impact of memory complaints on the concordance between self-report (SR) and electronically monitored (EM) medication adherence, independent of depression symptoms, among adults with type 2 diabetes (T2D).

METHODS

Adults (N = 104, age = 56.6 ± 9.2; 64% female) completed a prospective and retrospective memory questionnaire (PRMQ) and a depression symptom interview at baseline. EM was tracked over 3 months and participants rated adherence using SR. Multiple linear regression evaluated PRMQ as a moderator of the relationship between EM and SR, adjusting for depression and other covariates.

RESULTS

PRMQ was correlated with lower SR (r = -0.31, p = 0.001), but not with EM. PRMQ moderated the relationship between SR and EM, independent of depression symptoms. At low levels of PRMQ, SR and EM were closely related (β = 0.76, p < 0.001); at high levels of PRMQ the relationship was weaker (β = 0.28, p = 0.02). Participants who under-reported their adherence (SR < EM) had higher PRMQ scores than more concordant reporters (p = 0.016).

CONCLUSIONS

SR and EM measures were less concordant among adults with T2D who endorsed higher PRMQ scores. Memory complaints may contribute to under-reporting of medication adherence in adults with T2D.

Follow-Up Appointment Delay in Diabetic Macular Edema Patients

BACKGROUND AND OBJECTIVE

To evaluate a novel measure of compliance, follow-up appointment delay, and assess its relationship with clinical and sociodemographic factors in patients undergoing treatment for diabetic macular edema (DME).

PATIENTS AND METHODS

This is a comparative case series of patients treated for DME. The novel measure of compliance - the time in days from the intended day of return and actual day of return, or follow-up appointment delay - was studied and compared to a traditional measure: the percentage of visits missed. These were correlated with clinical and sociodemographic characteristics: best-corrected visual acuity, hemoglobin A1C percent (HbA1c), median household income, smoking status, type of insurance held, marital status, gender, and age. Univariate and multivariable analyses were conducted.

RESULTS

One hundred fifty-five patients (212 eyes) were included in the study. The median times between recommended and actual appointments was 5.0 days (range: 2.0-14.0 days). The mean percentage of visits missed was 31.7% (± 13.3%). The two measures of compliance were positively associated, but the correlation was moderate (r = 0.44). Non-white race, lack of bilateral injections, and higher baseline HBA1c were significant predictors of a median time greater than 7 days between the intended and actual follow-up dates.

CONCLUSIONS

The current study identified a novel method of measuring compliance of DME patients seen by retina specialists and has identified non-white race, lack for bilateral treatment, and poorer glycemic control as risk factors for noncompliance. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:200-206.].

The Clinical Utility and Ecological Validity of the Medication Management Ability Assessment in Older Adults with and without Dementia

OBJECTIVE

Older adults are susceptible to medication nonadherence, which may signify functional decline. Thus, performance-based proxies of medication-taking behavior may help diagnose dementia. We assessed the Medication Management Ability Assessment's (MMAA) clinical utility and ecological validity.

METHOD

This was a retrospective chart review of 180 outpatients (age = 72 ± 8 years) who completed the MMAA during clinical evaluations. Forty-seven were cognitively normal (CN), 103 had mild cognitive impairment (MCI), and 30 had dementia. Most (136) were independent in medication management, whereas 28 were assisted and 16 were dependent. Kruskal-Wallis tests assessed whether MMAA scores differed by diagnosis and independence. Receiver operating characteristic (ROC) analyses identified diagnostic cut-offs. Classification accuracy estimates were derived.

RESULTS

MMAA performance differed across diagnosis as expected (p's < .001). Those who were independent in medication management outperformed assisted and dependent counterparts (p's < .001). Assisted and dependent cases were no different. At a cut-off = 23, the MMAA was good-to-strong in distinguishing dementia from CN cases (Sn = 0.96, Sp = 0.83), dementia from MCI (Sn = 0.70, Sp = 0.83), and dementia from functionally unimpaired cases (Sn = 0.78, Sp = 0.83). At a cut-off = 27, it had good sensitivity but weaker specificity when distinguishing both MCI and all cognitively impaired patients (MCI and dementia) from CN cases (Sn = 0.81, Sp = 0.66 and Sn = 0.81, Sp = 0.72, respectively).

CONCLUSIONS

The MMAA has ecological validity and clinical utility in identifying dementia. Its inclusion in neuropsychological practice may be especially useful when medication mismanagement is suspected.

A New Self-management Scale with a Hierarchical Structure for Patients with Type 2 Diabetes

PURPOSE

The aims of this study were to develop a new instrument for measuring self-management with a hierarchical structure [the Diabetes Self-Management Scale (DSMS)] in patients with type 2 diabetes, and evaluate its psychometric properties.

METHOD

The DSMS instrument was developed in three phases: (1) conceptualization and item generation; (2) content validity and pilot testing; and (3) field testing of its psychometric properties. A convenience sample of 473 participants was recruited in three university hospitals and one regional health center, South Korea.

RESULTS

Exploratory and confirmatory factor analyses yielded two second-order component models explaining the common variance among six first-order factors. Principal axis factoring with a varimax rotation accounted for 60.88% of the variance. Confirmatory factor analysis of the hierarchical structure revealed the following fit indices: χ²/df = 1.373, standardized root-mean-square residual = .050, goodness-of-fit index = .935, incremental fit index = .975, comparative fit index = .974, and root-mean-square error of approximation = .039. All Cronbach' α values for internal consistency exceeded the criterion of .70. All of the intraclass correlation coefficients for test-retest reliability exceeded .70 except that for the taking-medication subscale. The components of the DSMS were moderately correlated with the comparator measures of self-efficacy and health literacy administered for convergent validity.

CONCLUSION

The DSMS is a new instrument for measuring the complex nature of self-management in patients with type 2 diabetes, comprising 17 items scored on a five-point Likert scale. The DSMS exhibits satisfactory psychometric properties for five reliability and validity metrics, and so is a suitable instrument to apply in both research and clinical practices.

Medication non-adherence in patients with type 2 diabetes mellitus with full access to medicines

Purpose

The pharmacological treatment for Type 2 diabetes mellitus (T2DM) is continuous and adherence to medication is critical for disease control. Restricted access to medicines is one of the most important barriers to adherence to T2DM treatment. This study aimed to evaluate other factors for medication non-adherence by studying patients with full access to oral hypoglycemic agents.

Methods

Cross-sectional study with 300 patients receiving their medication without costs from a referral center for diabetes care in Crato, Ceará (Brazil). Participants were recruited from January to December 2017. Information was obtained by self-applied questionnaires, and the drugs used were confirmed in the prescription. Adherence to medication was determined by the Morisky Medication Adherence Scale (MMAS-4). Patient perceptions of drugs were assessed by the Beliefs about Medicines Questionnaire (BMQ).

Results

Only 22.7% of participants met the criterion of high adherence to medication. The most frequent characteristics in the low adherence group were married; hypertension; no regular physical activity; therapy based on the combination of two or more oral antidiabetic agents without insulin; low score in the BMQ necessity scale. Necessity score in BMQ increased with age and the number of medications used and decreased if the patient had family members with the same disease and had children.

Conclusions

Full access to medicines did not assure high adherence to pharmacological treatment of type 2 diabetes mellitus. Distinctive factors to medication non-adherence may be found and specific barriers should be considered when planning actions for improving adherence in such populations.

Improving Glycemic Control in African Americans With Diabetes and Mild Cognitive Impairment

BACKGROUND/OBJECTIVES

Improving glycemic control in older African Americans with diabetes and mild cognitive impairment (MCI) is important as the population ages and becomes more racially diverse.

DESIGN

Randomized controlled trial.

SETTING

Recruitment from primary care practices of an urban academic medical center. Community-based treatment delivery.

PARTICIPANTS

Older African Americans with MCI, low medication adherence, and poor glycemic control (N = 101).

INTERVENTIONS

Occupational therapy (OT) behavioral intervention and diabetes self-management education.

MEASUREMENTS

The primary outcome was a reduction in hemoglobin A1c level of at least 0.5% at 6 months, with maintenance effects assessed at 12 months.

RESULTS

At 6 months, 25 of 41 (61.0%) OT participants and 22 of 46 (48.2%) diabetes self-management education participants had a reduction in hemoglobin A1c level of at least 0.5%. The model-estimated rates were 58% (95% confidence interval [CI] = 45%-75%) and 48% (95% CI = 36%-64%), respectively (relative risk [RR] = 1.21; 95% CI = 0.84-1.75; P = .31). At 12 months, the respective rates were 21 of 39 (53.8%) OT participants and 24 of 49 (49.0%) diabetes self-management education participants. The model-estimated rates were 50% (95% CI = 37%-68%) and 48% (95% CI = 36%-64%), respectively (RR = 1.05; 95% CI = 0.70-1.57; P = .81).

CONCLUSION

Both interventions improved glycemic control in older African Americans with MCI and poor glycemic control. This result reinforces the American Diabetes Association's recommendation to assess cognition in older persons with diabetes and demonstrates the potential to improve glycemic control in this high-risk population. J Am Geriatr Soc 68:1015-1022, 2020.

Patient-reported outcome measures for diabetes self-care: A systematic review of measurement properties

OBJECTIVES

The aims of the present systematic review were to identify currently available patient-reported outcome measures for diabetes self-care that have been psychometrically evaluated and to evaluate their measurement properties.

DESIGN

A systematic literature review with a meta-analysis.

DATA SOURCES

A systematic literature search was conducted of the MEDLINE, EMBASE, and CINAHL databases.

REVIEW METHODS

The updated COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) was applied using the following steps to evaluate the measurement properties of the diabetes self-care measures: (1) evaluating the methodological quality, (2) evaluating either quantitatively summarized or quantitatively pooled data against criteria for good measurement properties, and (3) the evaluating the quality of evidence by applying the modified Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

Among 8434 articles yielded by the database search, 27 full-text articles that reported 34 studies of 13 different patient-reported outcome measures were included in this systematic review. The Diabetes Self-Management Instrument demonstrated the best content validity, with sufficient moderate-quality evidence for relevance, comprehensiveness, and comprehensibility. The Diabetes Self-Management Instrument exhibited sufficient moderate-quality evidence for structural validity and internal consistency, and sufficient high-quality evidence for convergent validity of hypothesis testing and sufficient low-quality evidence for reliability. The eight-item Summary of Diabetes Self-Care Activities-Revised was the most frequently investigated and shortest instrument with sufficient high-quality evidence for structural validity and internal consistency. However, the sufficient but very-low-quality comprehensiveness and the inconsistent very-low-quality comprehensibility for content validity, and the insufficient low-quality evidence for reliability must be considered when selecting this instrument.

CONCLUSIONS

None of the identified diabetes self-care instruments appears to be universally superior to the others. The Diabetes Self-Management Instrument might be the best based on current evidence, but this requires further evaluation of the measurement of invariance across languages. The eight-item Summary of Diabetes Self-Care Activities-Revised is the shortest instrument, but current evidence with regards to its content validity and reliability needs to be considered before applying this instrument. Further studies are recommended to evaluate the reliability, measurement error, and responsiveness of the diabetes self-care measurements.

How Are Income and Education Related to the Prevention and Management of Diabetes?

Objective: To understand whether income and education have unique contributions in the prevention and management of diabetes, as measured by Hba1c levels among diagnosed and undiagnosed individuals. Method: Data were obtained from the Nashville Stress and Health Study (N = 1,189). Ordinary least squares regression analyses were used to examine the associations among education, annual household income, diabetes onset, and diabetes management (Hba1c). Results: Education, but not income, was inversely associated with Hba1c in undiagnosed participants. Income, but not education, was inversely associated with Hba1c among diagnosed participants. Discussion: These results support the idea that education and income provide non-fungible social and economic resources that vary in their consequences for Hba1c level depending on whether someone has been diagnosed with diabetes. The social resources provided by education may be more important in delaying the onset of disease, whereas resources provided by income may be more important for disease management.

Depressive symptom dimensions and medication non-adherence in suboptimally controlled type 2 diabetes

AIMS

Research suggests differential effects for somatic and cognitive-affective depressive symptoms in predicting health outcomes. This study evaluated differential relations with medication non-adherence among disadvantaged, and predominantly immigrant adults with sub-optimally controlled type 2 diabetes (T2D).

METHODS

Health plan members taking oral diabetes medication and who had A1c ≥ 7.5% were recruited for a trial of telephonic self-management support. A subset (n = 376; age, M = 55.6 ± 7.2 years; A1c M = 9.1% ± 1.6) completed the Patient Health Questionnaire-8 (PHQ-8). Diabetes medication adherence was measured by self-report and claims-based records. Multivariable logistic regression modeled depressive symptoms and odds of non-adherence using pre-intervention data.

RESULTS

A positive PHQ-8 screen (OR = 2.72 [95%CI: 1.56-4.73]) and each standard deviation increase in PHQ-8 score (OR = 1.40 [95%CI: 1.11-1.75]) were associated with non-adherence, with no independent effects for somatic versus cognitive-affective symptoms. Exploration of individual symptoms identified three significantly associated with non-adherence in covariate-adjusted models; after adjustment for likely presence of clinical depression, only fatigue was independently associated with non-adherence (OR = 1.71 [95%CI: 1.06-2.77]).

CONCLUSIONS

Findings support depression symptom severity as a significant correlate of medication non-adherence among disadvantaged adults with T2D. Support was limited for differential associations for symptom dimensions, but findings suggest that fatigue may be associated with non-adherence independent of the likely presence of depression.

Comparing Real-Time Self-Tracking and Device-Recorded Exercise Data in Subjects with Type 1 Diabetes

BACKGROUND

Insulin therapy, medical nutrition therapy, and physical activity are required for the treatment of type 1 diabetes (T1D). There is a lack of studies in real-life environments that characterize patient-reported data from logs, activity trackers, and medical devices (e.g., glucose sensors) in the context of exercise.

OBJECTIVE

The objective of this study was to compare data from continuous glucose monitor (CGM), wristband heart rate monitor (WHRM), and self-tracking with a smartphone application (app), iDECIDE, with regards to exercise behaviors and rate of change in glucose levels.

METHODS

Participants with T1D on insulin pump therapy tracked exercise for 1 month with the smartphone app while WHRM and CGM recorded data in real time. Exercise behaviors tracked with the app were compared against WHRM. The rate of change in glucose levels, as recorded by CGM, resulting from exercise was compared between exercise events documented with the app and recorded by the WHRM.

RESULTS

Twelve participants generated 277 exercise events. Tracking with the app aligned well with WHRM with respect to frequency, 3.0 (2.1) and 2.5 (1.8) days per week, respectively (p = 0.60). Duration had very high agreement, the mean duration from the app was 65.6 (55.2) and 64.8 (54.9) minutes from WHRM (p = 0.45). Intensity had a low concordance between the data sources (Cohen's kappa = 0.2). The mean rate of change of glucose during exercise was -0.27 mg/(dL*min) and was not significantly different between data sources or intensity (p = 0.21).

CONCLUSION

We collated and analyzed data from three heterogeneous sources from free-living participants. Patients' perceived intensity of exercise can serve as a surrogate for exercise tracked by a WHRM when considering the glycemic impact of exercise on self-care regimens.

Measuring adherence to oral antidiabetic multi-drug treatment: Comparative validity of prescription claims-based adherence measures against hospitalization

BACKGROUND

The use of prescription claims data to measure adherence to diabetes treatment is very common in research. However, there is no clear evidence regarding the accuracy of the methods used to assess adherence to multi-drug treatments for the many patients using multiple antidiabetic drugs.

PURPOSE

To assess the validity of prescription claims-based adherence measures in the context of multiple oral antidiabetic drug treatment.

METHODS

A cohort of patients who began their antidiabetic drug treatment with at least two oral antidiabetic drugs (new users) was created using Quebec medico-administrative data. Four different prescription claims-based adherence measures were assessed: proportion of days covered (PDC) by at least one class of drugs, mean PDC, PDC by all classes and daily polypharmacy possession ratio (DPPR). All-cause and diabetes-related hospitalizations were the validation criteria. To assess the validity of the measures, receiver operating characteristic (ROC) curves were plotted for each measure and each criterion.

RESULTS

A total of 5982 individuals were included. The areas under the ROC curves for the PDC by at least one class of drugs, the mean PDC, the PDC by all classes of drugs and the DPPR were respectively 0.54 (95% CI: 0.52-0.56), 0.51 (0.49-0.53), 0.50 (0.48-0.52) and 0.51 (0.49-0.53) with all-cause hospitalization as criterion and 0.55 (0.53-0.57), 0.53 (0.51-0.55), 0.51 (0.49-0.53) and 0.53 (0.51-0.55) using diabetes-related hospitalization as criterion.

CONCLUSIONS

The results suggest that all measures have poor validity in predicting hospitalizations thus raising concerns about their utility in the assessment of adherence to multi-drug treatment. Future research should assess the capacity of these measures to predict other outcomes more closely related to medication adherence.

Advancing the Science and Practice of Medication Adherence

Medication adherence remains a significant unmet challenge for optimizing patient outcomes. Recent advances in the conceptualization, measurement, and support of medication adherence offer fresh opportunities to make a meaningful impact on adherence-related behavior and outcomes. These advances emphasize the multifaceted and dynamic nature of medication adherence, provide novel methods for monitoring medication adherence in clinical care, and articulate a set of multilevel strategies to more effectively improve and sustain medication adherence. Here, we offer recommendations for how clinicians can better engage with, and benefit from, these innovations to improve patient medication adherence and associated treatment outcomes.

Treatment Adherence and Its Associated Factors in Patients with Type 2 Diabetes: Results from the Rio de Janeiro Type 2 Diabetes Cohort Study

OBJECTIVES

To investigate treatment adherence in patients with type 2 diabetes and to evaluate its associated factors.

METHODS

The Summary of Diabetes Self-Care Activities (SDSCA) questionnaire was used to assess treatment adherence. Good adherence was defined as ≥5 days a week in each SDSCA item. Pain, emotional, and physical domains of the SF-36 quality of life questionnaire and the Canadian Occupational Performance Measure (COPM) were also evaluated. Multivariable logistic regressions explored the independent correlates of good general adherence and of specific items of the SDSCA (diet, exercise, and medications).

RESULTS

Good adherence was 93.5% for medication use, 59.3% for foot care, 56.1% for blood glucose monitoring, 29.2% for diet, and 22.5% for exercise. Patients with general good adherence had lower BMI, better serum lipid profile, higher values of functional capacity, emotional and pain domains of SF-36, better occupational performance, and lower prevalence of pain or limitation in the upper and lower limbs than patients with worse adherence. The variables associated with good adherence were younger age, lower BMI, presence of macrovascular complications, better occupational performance and emotional domain of SF-36, and higher HDL cholesterol levels. The presence of pain/limitation in the upper limbs was associated with worse adherence. Good medication adherence was associated with longer diabetes duration, lower BMI, and lower HbA_1c levels. Higher values of pain and emotional domains of the SF-36 and lower BMI were related to better exercise and diet adherence, while the presence of peripheral neuropathy and joint pain/limitation were associated with worse exercise adherence.

CONCLUSIONS

Emotional and physical performances are important determinants of good diabetic treatment adherence. Good adherence has beneficial impact on BMI, lipid, and glycemic control.

Psychosocial factors in medication adherence and diabetes self-management: Implications for research and practice

Diabetes is a chronic illness that places a significant self-management burden on affected individuals and families. Given the importance of health behaviors-such as medication adherence, diet, physical activity, blood glucose self-monitoring-in achieving optimal glycemic control in diabetes, interventions designed and delivered by psychologists hold promise in assisting children, adolescents, and adults with diabetes in improving their health status and lowering their risk of serious complications. This article first provides an overview of diabetes self-management and associated challenges and burdens. Socioeconomic status factors that may influence diabetes management and outcomes are briefly highlighted. We then review the evidence base for select psychosocial factors that may be implicated in diabetes self-management. Modifiable targets of psychological intervention are presented across 3 overarching domains: (a) knowledge, beliefs, and related cognitive constructs; (b) emotional distress and well-being; and (c) behavioral skills and coping. Important methodological issues facing future research are discussed, along with opportunities for psychologists in improving the care and treatment outcomes of individuals and families living with diabetes. In conclusion, we advocate for continued research emphasis on improving psychosocial aspects of living with diabetes, with greater attention to the situational context in which the self-regulatory processes underlying self-management occur. Psychologists have important roles to play in reducing emotional distress, improving patient knowledge, and providing training in behavioral skills to promote successful self-management and to support patient-centered diabetes care. (PsycINFO Database Record

Medication adherence as a predictor of 30-day hospital readmissions

PURPOSE

The aim of this study was to test whether patient medication adherence, a modifiable risk factor obtainable at hospital admission, predicts readmission within 30 days.

PATIENTS AND METHODS

We used a retrospective cohort study design to test whether patient medication adherence to all chronic medications, as determined by the 4-item Morisky Medication Adherence Scale (MMAS-4) administered by a pharmacist at the time of hospital admission, predicts 30-day readmissions. We compared readmission rates among 385 inpatients who had their adherence assessed from February 1, 2013, to January 31, 2014. Multiple logistic regression was used to examine the benefit of adding medication adherence to previously published variables that have been shown to predict 30-day readmissions.

RESULTS

Patients with low and intermediate adherence (combined) had readmission rates of 20.0% compared to a readmission rate of 9.3% for patients with high adherence (P=0.005). By adding MMAS-4 data to previously published variables that have been shown to predict 30-day readmissions, we found that patients with low and intermediate medication adherence had an adjusted 2.54-fold higher odds of readmission compared to those in patients with high adherence (95% confidence interval [CI]: 1.32-4.90, P=0.005). The model's predictive power, as measured by the c-statistic, improved from 0.65 to 0.70 after adding adherence.

CONCLUSION

Because medication adherence assessed at hospital admission was independently associated with 30-day readmission risk, it offers potential for targeting interventions to improve adherence.

Treatment adherence and illness self-management: introduction to the special issue

The current issue is devoted broadly to research on treatment adherence and chronic illness self-management behavior. As the prevalence of chronic illness increases, the pervasive problem of treatment nonadherence is increasingly viewed as having a major impact on treatment outcomes, public health and healthcare costs, making this issue particularly timely. Sixteen articles spanning an array of topics are presented; articles include empirical studies, statistical simulations, systematic reviews, and theoretical commentaries. Studies conducted with diverse patient populations (e.g., chronic headache, diabetes, end-stage renal disease, HIV, hypertension, severe obesity), samples (e.g., adolescents, ethnic/racial minorities, low-income adults, parents, spousal dyads), and designs (e.g., cross-sectional, longitudinal assessment, randomized controlled trial), are represented. This issue highlights psychosocial factors associated with nonadherence, promising interventions to promote adherence, and state-of-the art methods for the study of illness self-management. We hope these articles engender even more high quality, methodologically rigorous research in this important subfield of behavioral medicine.

Medication Adherence Affects Risk of New Diabetes Complications

Background: Previous outcomes-based studies of adherence to diabetes medications have focused on glycemic control and are limited by questions of temporality and uncontrolled confounding. Objective: This retrospective cohort study of new oral antidiabetic medication users examined the effect of adherence on risk of incident macrovascular and microvascular complications. Methods: A nationwide integrated insurance claims and laboratory database was used to identify new oral antidiabetic medication users between January 2004 and December 2009. People with preexisting complications were excluded and the remaining cohort was followed until development of a new diabetes complication or December 2010. Medication adherence was calculated at 3-month intervals and entered as a time-dependent variable in a Cox proportional hazards model. Covariables entered in the model included patient demographics, clinical laboratory data, a medical frailty indicator and a mortality risk score from the Johns Hopkins adjusted clinical groups system, and medication use at baseline. Results: Among the 54 505 included patients, the median age was 60 years, 28 125 (52%) were men, 1447 (3%) were considered frail, the mean mortality risk score was 33.7 (±11.1), and 9793 (18%) developed a new diabetes complication. Good adherence (medication possession ratio ≥0.8) was associated with a lower risk of a new microvascular or macrovascular diabetes complication (adjusted hazard ratio = 0.96; 95% CI = 0.92-1.00; P = 0.05). Conclusions: This study design addresses limitations of previous studies and found a small but significantly lower risk of new diabetes complications associated with good adherence to oral antidiabetic medications.

Medication-taking behaviour in New South Wales patients with type 2 diabetes: an observational study

This study aimed to (1) determine adherence to diabetes medication in type 2 diabetes (T2D) patients; (2) describe respondents' attitudes and beliefs about medications, and barriers to adherence; and (3) to model predictors of non-adherence. Data were collected using online and postal surveys. Diabetes patients aged 18 years who were members of the Australian Diabetes Council were invited to participate. Main outcome measures were adherence to diabetes medication using 8-item Morisky Medication Adherence Score (MMAS-8) and beliefs about medication using the Beliefs about Medicines Questionnaire. A total of 543 T2D patients responded to the survey. The median (interquartile range) MMAS-8 score was 6.8 (5.0-7.0). The prevalence of adherence (MMAS-8 score 6) was 64.6%. The proportion of respondents who expressed concern about taking medications was 53.6%. Potential predictors of adherence included age (OR, 1.83; 95% CI, 1.19-2.82), concern about medication (OR, 0.91; 95% CI, 0.87-0.96), knowledge of diabetes (OR, 0.85, 95% CI, 0.73-0.99), having difficulty in paying for medication (OR, 0.51; 95% CI, 0.33-0.79), having more than one regular pharmacy (OR, 0.59; 95% CI, 0.36-0.95), and using insulin (OR, 0.49; 95% CI, 0.30-0.81). Adherence to taking diabetes medication in a sample of the Australian T2D patient population was suboptimal. An understanding of medication-taking behaviour will assist health-care professionals to deliver appropriate and effective interventions to enhance adherence and optimise diabetes control in T2D patients.

Measuring insulin adherence among adults with type 2 diabetes

Non-adherence to insulin is common and associated with suboptimal health. We adapted the Morisky Medication Adherence Scale to specify insulin adherence (MIAS) and compared it to the Adherence to Refills and Medication Scale for Diabetes (ARMS-D) and the Summary of Diabetes Self-Care Activities medications subscale (SDSCA-MS) and an insulin-specific (SDSCA-IS) version. A sample of 144 insulin-treated adults (58 % African American/Black, 34 % Caucasian/White, 8 % Other/Mixed race; 6.9 % Hispanic) completed these measures along with a HbA1C test. The internal consistency and factor structure of the MIAS were adequate; 59 % of participants forgot to take insulin and 46 % reported non-adherence. The MIAS was associated with the ARMS-D, SDSCA-MS, and SDSCA-IS (p < 0.001), and higher MIAS scores were marginally associated with better self-rated health (p = 0.057), but significantly associated with fewer emergency room visits (p = 0.001), and better HbA1C (p = 0.001). The MIAS is a valid and reliable insulin adherence assessment tool for practice and research applications.

Medication adherence may be more important than other behaviours for optimizing glycaemic control among low-income adults

WHAT IS KNOWN

Patients with type 2 diabetes mellitus (T2DM) are required to perform multiple self-care behaviours to achieve and maintain optimal glycaemic control (HbA1c), which prevents complications and premature mortality. Patients with T2DM and low socioeconomic status (SES) are more likely to have suboptimal HbA1c, often due to being less adherent to recommended self-care activities than their higher-SES counterparts.

OBJECTIVE

Although studies support performing certain diabetes self-care behaviours for optimizing glycaemic control, there is limited research on the relative importance of each behaviour for this purpose. Identifying what behaviours are most important for HbA1c among low-SES patients with T2DM would be particularly useful for informing policy and intervention efforts for this high-risk group.

METHODS

In a cross-sectional study of 314 adults with T2DM and low SES, we used the Summary of Diabetes Self-Care Activities to assess self-care behaviours and multivariate models to test which behaviours were associated with lower HbA1c.

RESULTS AND DISCUSSION

Only medication adherence was significantly associated with lower HbA1c after adjusting for the other self-care behaviours (β = -0·14, P = 0·028) and further adjusting for demographic and diabetes characteristics (β = -0·16, P = 0·024).

WHAT IS NEW

Medication adherence may be the most important self-care behaviour for glycaemic control among adults with T2DM and low SES.

CONCLUSION

Focused efforts to improve medication adherence among low-SES patient populations may improve glycaemic control.

Psychometric Evaluation of a Korean Version of the Adherence to Refills and Medications Scale (ARMS) in Adults With Type 2 Diabetes

PURPOSE

The purpose of the study was to examine the reliability and validity of the Adherence to Refills and Medications Scale-Korean (ARMS-K) among Korean adults with type 2 diabetes.

METHODS

The Korean translated ARMS-K was back-translated to ensure translation equivalency. A cross-sectional survey was used to evaluate the psychometric properties with exploratory factor analysis for validity and Cronbach's alpha coefficients for reliability.

RESULTS

The factor analysis of construct validity identified 3 dimensions of the ARMS-K, explaining 54.7% of the total variance. The internal consistency reliability for the total instrument was acceptable with a Cronbach's alpha of .801. There was good correlation between the ARMS-K and 8-item Morisky Medication Adherence Scale-Korean version (r = -0.698), indicating that these scales measure theoretically related constructs as evidence of convergent validity. As evidence of known groups validity, there was a significant association between the ARMS-K score and glycemic control (P = .048), indicating that the good glycemic controlled group was more likely to have a higher rate of adherence to refills and medications than the poor glycemic controlled group.

CONCLUSIONS

These results support the cross-cultural applicability of the concepts underlying the ARMS-K. The ARMS-K can be used not only to assess adherence to refills and medications in Koreans with diabetes but also to examine the potential role of adherence to refills and medications in enhanced glycemic control of people with diabetes in a variety of clinical settings.

Adherence in adolescents with Type 1 diabetes: strategies and considerations for assessment in research and practice

Suboptimal adherence remains a significant concern for adolescents with Type 1 diabetes, the treatment regimen for which is complex and includes numerous behaviors. Accurate assessment of adherence is critical for effective healthcare and to measure trial outcomes. Without a valid biomarker of adherence, assessment strategies must rely on measuring management behaviors. This paper provides an overview of approaches to measure adherence, with an emphasis on contemporary, validated measures that are appropriate for current diabetes care. Objective measures include electronic data from diabetes management devices. Subjective measures include self/parent-report questionnaires, structured interviews and diaries/logbooks. Practical strategies for selecting measurement approaches for clinical and research purposes are reviewed, and implications of adherence assessment for clinical care delivery and adherence-promotion are discussed.

Predictive Validity of Self-Reported Measures of Adherence to Noninsulin Antidiabetes Medication against Control of Glycated Hemoglobin Levels

OBJECTIVE

To assess and compare the predictive validity of 4 self-reported adherence measures.

METHODS

A convenience sample of 153 patients with type 2 diabetes completed a self-report with 4 items (SR-4) and a French version of the Morisky Medication Adherence Scale with 8 items (MMAS-8), reported the proportion of pills missed, and answered a single-item scale regarding their antidiabetes drug treatments. They also provided measures of glycated hemoglobin (A1C) taken between 3 and 6 months after the adherence measurements. We examined the relationship between self-reported adherence and glycemic control using the area under the receiver operating characteristics curve (AUC) and linear regression analyses.

RESULTS

AUCs were 0.51, 0.52, 0.53 and 0.52 for the SR-4, MMAS-8, self-reported proportion of pills missed and single-item scale, respectively. AUCs stratified according to median duration of diabetes ranged from 0.55 to 0.63. Based on linear regression analyses adjusted for diabetes duration, the association measured in the total sample between adherence measures and A1C levels was not statistically significant. When regression analyses were performed among participants with A1C levels ≥7% only, SR-4, MMAS-8 and the single-item scale scores were significantly associated with A1C levels, and beta coefficients were associated with a 1-unit increase in adherence scores of -0.46, -0.20 and 0.38, respectively.

CONCLUSION

The results support the predictive validity of all measures except the self-reported proportion of missed pills.

Self-report measures of medication adherence behavior: recommendations on optimal use

Medication adherence plays an important role in optimizing the outcomes of many treatment and preventive regimens in chronic illness. Self-report is the most common method for assessing adherence behavior in research and clinical care, but there are questions about its validity and precision. The NIH Adherence Network assembled a panel of adherence research experts working across various chronic illnesses to review self-report medication adherence measures and research on their validity. Self-report medication adherence measures vary substantially in their question phrasing, recall periods, and response items. Self-reports tend to overestimate adherence behavior compared with other assessment methods and generally have high specificity but low sensitivity. Most evidence indicates that self-report adherence measures show moderate correspondence to other adherence measures and can significantly predict clinical outcomes. The quality of self-report adherence measures may be enhanced through efforts to use validated scales, assess the proper construct, improve estimation, facilitate recall, reduce social desirability bias, and employ technologic delivery. Self-report medication adherence measures can provide actionable information despite their limitations. They are preferred when speed, efficiency, and low-cost measures are required, as is often the case in clinical care.

Adherence to diabetes medication: a systematic review

AIMS

To investigate the extent of and factors associated with adherence to Type 2 diabetes medication.

METHODS

The CINAHL, Embase, International Pharmaceutical Abstracts, Medline, PubMed and PsychINFO databases were searched for the period January 2004 to July 2013. Papers were included in the present review if they reported the prevalence of adherence (the percentage of the study population that is classified as adherent) to Type 2 diabetes medication and used validated adherence measures with a defined cut-off point to indicate adherence. Reported factors were classified as potential predictors if the studies that examined that particular variable reported consistent findings.

RESULTS

Of the 27 studies included in the present review, the prevalence of adherence ranged from 38.5 to 93.1%. Only six out of 27 studies (22.2%) reported prevalence of adherence of ≥ 80% among their study population. Depression and medication cost were found to be consistent and potentially modifiable predictors for diabetes medication-taking behaviour. The associations between adherence and other factors were inconsistent among the reviewed studies.

CONCLUSIONS

Adherence to diabetes medication remains an ongoing problem. This review has highlighted the urgent need to develop consensus about what constitutes good adherence in diabetes. Further research is needed to clarify modifiable factors, in addition to depression and medication cost, that influence adherence and may provide a focus for targeted interventions to promote adherence, optimize diabetes control and limit the progression of diabetes.

Defining the role of medication adherence in poor glycemic control among a general adult population with diabetes

Aims

This study assesses the attributable impact of adherence to oral glucose medications as a risk factor for poor glycemic control in population subgroups of a large general population, using an objective medication adherence measure.

Methods

Using electronic health records data, adherence to diabetes medications over a two-year period was calculated by prescription-based Medication Possession Ratios for adults with diabetes diagnosed before January 1, 2010. Glycemic control was determined by the HbA1c test closest to the last drug prescription during 2010–2012. Poor control was defined as HbA1c>75 mmol/mol (9.0%). Medication adherence was categorized as “good” (>80%), “moderate” (50–80%), or “poor” (<50%). Logistic regression models assessed the role medication adherence plays in the association between disease duration, age, and poor glycemic control. We calculated the change in the attributable fraction of glucose control if the non-adherent diabetic medication population would become adherent by age-groups.

Results

Among 228,846 diabetes patients treated by oral antiglycemic medication, 46.4% had good, 28.8% had moderate, and 24.8% had poor adherence. Good adherence rates increased with increasing disease duration, while glycemic control became worse. There was a strong inverse association between adherence level and poor control (OR = 2.50; CI = 2.43–2.58), and adherence was a significant mediator between age and poor control.

Conclusions

A large portion of the diabetes population is reported to have poor adherence to oral diabetes medications, which is strongly associated with poor glycemic control in all disease durations. While poor adherence does not mediate the poorer glycemic control seen in patients with longer-standing disease, it is a significant mediator of poor glycemic control among younger diabetes patients. A greater fraction of poorly controlled younger patients, compared to older patients, could be prevented if at least 80% adherence to their medications was achieved. Therefore, our results suggest that interventions to improve adherence should focus on this younger sub-group.

Determinants of Cost-Related Nonadherence to Medications among Chronically Ill Patients in Maccabi Healthcare Services, Israel

BACKGROUND

The effectiveness of value-based insurance design is based on nonadherence, which derives solely from patients' economic constraints.

OBJECTIVE

Our objective was to examine the extent of cost-related nonadherence to chronic medications and to analyze its potential determinants.

METHODS

We conducted a telephone survey among a representative sample of Maccabi Healthcare Services chronically ill patients aged 55 years or older (n = 522). We developed a 12-month recall questionnaire that included demographic and socioeconomic characteristics, out-of-pocket expenditure on prescribed medication, physician's provision of explanation regarding prescribed therapy, adherence, and reasons for nonadherence. Respondents were defined as nonadherent if they reported that they did not purchase prescribed medications in the previous year because of their cost. We applied the multivariable logistic regression model to examine predictors of nonadherence.

RESULTS

Median (interquartile range) age of the study sample was 69 (13) years (53% males). One hundred sixty-five patients (31.6%) reported not purchasing prescribed medications mainly because of medications' adverse effects and/or cost. Fifty respondents (9.6%) reported cost-related nonadherence. The multivariable logistic regression model revealed that cost-related nonadherence was associated with respondent's income lower than 4600 New Israeli shekel (odds ratio [OR] = 10.86; 95% confidence interval [CI] 1.45-81.12), unemployment (OR = 4.32; 95% CI 1.47-12.66), lack of physician explanation about the prescribed medication (OR = 2.38; 95% CI 1.18-4.78), and age (OR = 0.95; 95% CI 0.91-0.99).

CONCLUSIONS

Cost-related nonadherence to chronic pharmaceuticals is self-reported among nearly 10% of the chronically ill patients and is strongly affected by low socioeconomic status, even under universal health insurance coverage and with relatively low co-payments as applied in Israel. Lack of information provided by physicians regarding the therapy is associated with a higher likelihood of cost-related nonadherence.

A systematic literature review of methodologies used to assess medication adherence in patients with diabetes

OBJECTIVE

Adhering to prescribed medication is often a problem for patients with diabetes yet there is no consensus on how best to measure adherence in this patient population. This systematic literature review critically reviewed and summarized the methods used to measure medication adherence in patients with diabetes (on oral hypoglycemic agents [OHAs] and/or insulin) in original research published between 2007-2013.

STUDY DESIGN

Literature review.

METHODS

A systematic search for methods to assess medication adherence in patients with type I or type II diabetes was conducted using PubMed, EMBASE, PsychInfo, and Cochrane databases. Two researchers independently screened abstracts for initial eligibility and then applied the inclusion/exclusion criteria to the relevant full-text articles.

RESULTS

Fifty-nine articles met the criteria for inclusion. Subjective assessment (observer-reported and patient-reported), pill counts, Medication Event Monitoring System (MEMS), cell-phone real-time assessment, and logbooks were used in prospective studies. In pharmacy claims databases, medication possession ratios (MPRs), or some derivation thereof, were utilized. Each method has strengths and weaknesses, but few approaches specifically addressed issues unique to assessing insulin adherence. Three novel approaches (using cell-phone real-time assessment, computerized logbooks, and a questionnaire about different dosing irregularities) provided insight on timing and dosing issues that could be useful for highlighting interventions to improve insulin adherence.

CONCLUSION

No gold standard exists for measuring medication adherence in patients with diabetes. The plethora of adherence methods precludes the comparison of adherence rates across studies. Greater consistency is therefore needed in adherence measurement, including question content, recall period, and response options for self-report measures. Novel methods for understanding adherence to variable-dosed insulin require further research. Researchers should select a methodology that best fits their research question, study design, patient population and resources.

Risk perception and self-management in urban, diverse adults with type 2 diabetes: the improving diabetes outcomes study

PURPOSE AND BACKGROUND

The relationship between risk perceptions and diabetes self-care remains ambiguous. This study aimed to assess baseline, 1-year follow-up, and change score relationships among perceived risk, diabetes self-care, and glycemic control for adult individuals participating in a behavioral intervention that improved glycemic control relative to the active control.

METHOD

One-year randomized trial compared a behavioral telephonic intervention with a print only intervention. Participants (N = 526) are members of a union/employer sponsored health benefit plan, with HbA(1c) ≥ 7.5 %, prescribed at least one oral diabetes medication. Participants rated perceived risk of diabetes and its complications and diabetes self-care at baseline and 1 year. Data were collected in a large urban area in the USA.

RESULTS

There were no relationships between risk perceptions and glycemic control during the study. Baseline perceived risk predicted follow-up self-care. Additionally, participants assigned to the intervention group showed significant changes in dietary and exercise adherence at high levels of risk knowledge and low levels of optimistic bias.

CONCLUSION

Perceived risk relates to dietary, exercise, and medication adherence in diabetes. The perceived risk construct might foster a more coherent conceptualization of the relationship between one's diabetes, possible complications, and diabetes self-care behaviors.

Psychometric properties of a short self-reported measure of medication adherence among patients with hypertension treated in a busy clinical setting in Korea

Background

We examined the psychometric properties of the Korean version of the 8-item Morisky Medication Adherence Scale (MMAS-8) among adults with hypertension.

Methods

A total of 373 adults with hypertension were given face-to-face interviews in 2 cardiology clinics at 2 large teaching hospitals in Seoul, South Korea. Blood pressure was measured twice, and medical records were reviewed. About one-third of the participants (n = 109) were randomly selected for a 2-week test-retest evaluation of reliability via telephone interview.

Results

Internal consistency reliability was moderate (Cronbach α = 0.56), and test-retest reliability was excellent (intraclass correlation = 0.91; P < 0.001), although a ceiling effect was detected. The correlation of MMAS-8 scores with scores for the original 4-item scale indicated that convergent validity was good (r = 0.92; P < 0.01). A low MMAS-8 score was significantly associated with poor blood pressure control (χ² = 29.86; P < 0.001; adjusted odds ratio = 5.08; 95% CI, 2.56–10.08). Using a cut-off point of 6, sensitivity and specificity were 64.3% and 72.9%, respectively. Exploratory factor analysis identified 3 dimensions of the scale, with poor fit for the 1-dimensional construct using confirmatory factory analysis.

Conclusions

The MMAS-8 had satisfactory reliability and validity and thus might be suitable for assessment and counseling regarding medication adherence among adults with hypertension in a busy clinical setting in Korea.

Use of technology when assessing adherence to diabetes self-management behaviors

During the last several decades, a proliferation of sophisticated technology has taken place to facilitate diabetes self-management and improve health outcomes. Blood glucose monitors, insulin pumps, and continuous glucose monitors have significant data storage capacity, which can be used to summarize diabetes health management and outcomes. In the absence of technology errors or failures, and in the context of the multiple psychosocial factors associated with nonadherence, these data have the potential to elucidate diabetes care because they reflect actual patient behaviors. This review provides a summary of the diabetes adherence literature in the context of current American Diabetes Association Clinical Practice Recommendations with a focus on studies that have used objective methods (ie, data derived from technology) to assess diabetes care provider and patient adherence in the areas of glucose monitoring; insulin administration and antihyperglycemic medications; medical nutrition therapy; and physical activity.

Health literacy, physician trust, and diabetes-related self-care activities in Hispanics with limited resources

BACKGROUND

Hispanics with diabetes often have deficits in health literacy (HL). We examined the association among HL, psychosocial factors, and diabetes-related self-care activities.

METHODS

Cross-sectional analysis of 149 patients. Data included patient demographics and validated measures of HL, physician trust, self-efficacy, acculturation, self-care behaviors, and A1c.

RESULTS

Participants (N=60) with limited HL were older and less educated, and had more years with diabetes compared with adequate HL participants (N=89). Limited HL participants reported greater trust in their physician, greater self-efficacy, and better diet, foot care, and medication adherence. Health literacy status was not associated with acculturation or A1c. In adjusted analyses, HL status remained associated with physician trust, and we observed a notable but nonsignificant trend between HL status and medication adherence.

DISCUSSION

Lower HL was associated with greater physician trust and better medication adherence. Further research is warranted to clarify the role of HL and physician trust in optimizing self-care for Hispanics.

The ARMS-D out performs the SDSCA, but both are reliable, valid, and predict glycemic control

AIMS

The Adherence to Refills and Medications Scale (ARMS) has been associated with objective measures of adherence and may address limitations of existing self-report measures of diabetes medication adherence. We modified the ARMS to specify adherence to diabetes medicines (ARMS-D), examined its psychometric properties, and compared its predictive validity with HbA1C against the most widely used self-report measure of diabetes medication adherence, the Summary of Diabetes Self-Care Activities medications subscale (SDSCA-MS). We also examined measurement differences by age (<65 vs. ≥65 years) and insulin status.

METHODS

We administered self-report measures to 314 adult outpatients prescribed medications for type 2 diabetes and collected point-of-care HbA1C.

RESULTS

One of the 12-item ARMS-D items was identified as less relevant to adherence to diabetes medications and removed. The 11-item ARMS-D had good internal consistency reliability (α=0.86), maintained its factor structure, and had convergent validity with the SDSCA-MS (rho=-0.52, p<0.001). Both the ARMS-D (β=0.16, p<0.01) and the SDSCA-MS (β=-0.12, p<0.05) independently predicted HbA1C after adjusting for covariates, but this association did not hold among participants ≥65 years in subgroup analyses. There were no differences in ARMS-D or SDSCA-MS scores by insulin status, but participants on insulin reported more problems with adherence on two ARMS-D items (i.e., feeling sick and medicine costs).

CONCLUSIONS

The ARMS-D is a reliable and valid measure of diabetes medication adherence, and is more predictive of HbA1C than the SDSCA-MS, but takes more time to administer. The ARMS-D also identifies barriers to adherence, which may be useful in research and clinical practice.

Reliability and validity of a self-reported measure of medication adherence in patients with type 2 diabetes mellitus in Korea

OBJECTIVE

This study examined the psychometric properties of the Korean version of the eight-item Morisky Medication Adherence Scale (MMAS-8) to measure adherence to diabetes medication in patients with type 2 diabetes mellitus.

METHODS

The English version of the MMAS-8 was translated into Korean and administered to patient with type 2 diabetes mellitus via face-to-face interviews, conducted by an independent interviewer. Patient characteristics and glycosylated haemoglobin (HbA1c) levels were assessed at the same clinic visit. A proportion of patients was randomly selected for 2-week test-retest reliability via telephone interviews. Convergent validity of the MMAS-8 against a four-item MMAS, correlations with HbA1c levels and construct validity of the MMAS-8 were evaluated.

RESULTS

In total, 317 patients were included; 70 completed the 2-week test-retest interview. Internal consistency reliability was moderate and test-retest reliability of the MMAS-8 was excellent, although a ceiling effect was detected. Good convergent validity was shown by the high correlation of the new scale scores with the original MMAS-4. A significant association was found between MMAS-8 scores and HbA1c levels. Using glycaemic control as a gold standard, sensitivity was 74.1% and specificity was 38.3%. Explanatory factor analysis identified three dimensions of the scale.

CONCLUSIONS

In light of acceptable reliability and validity, the MMAS-8 is a simple and quick method for the assessment of medication adherence among patient with type 2 diabetes mellitus, in a busy clinic setting.

Validity of medication adherence self-reports in adults with type 2 diabetes

OBJECTIVE

To assess the validity of self-report measures of diabetes medication adherence and evaluate the effect of depression on the validity of these reports.

RESEARCH DESIGN AND METHODS

Adults with type 2 diabetes, treated with oral medications, completed a set of medication adherence self-reports that varied response scales and time frames, were administered structured clinical interviews for depression, and provided blood samples for HbA(1c) as part of a screening for an intervention study. A subsample of participants with HbA(1c) ≥7.0% and clinically significant depression received Medication Event Monitoring System (MEMS) bottle caps to record adherence. Analyses examined relationships between adherence measures and HbA(1c) and, in the subsample, MEMS. Moderated linear regression evaluated whether depression severity modified relationships with HbA(1c).

RESULTS

Participant (n = 170, 57% men, 81% white, mean HbA(1c) 8.3% [SD, 1.7]) adherence self-reports were significantly (r = -0.18 to -0.28; P < 0.03) associated with lower HbA(1c). In the subsample (n = 88), all self-reports were significantly (r = 0.35 to 0.55; P ≤ 0.001) associated with MEMS-measured adherence. Depression significantly moderated the relationship between three of six self-reports and HbA(1c); at high levels of depression, associations with HbA(1c) became nonsignificant.

CONCLUSIONS

Results support the validity of easily administered self-reports for diabetes medication adherence. One-month, percentage-based ratings of adherence had the strongest associations with MEMS and HbA(1c); those requiring the report of missed doses had weaker associations. One-week self-ratings and measures that require respondents to record the number of missed doses appear to be vulnerable to bias from depression severity.

Communication and medication refill adherence: the Diabetes Study of Northern California

BACKGROUND

Poor medication refill adherence contributes to poor cardiometabolic control and diabetes outcomes. Studies linking communication between patients and health care providers to adherence often use self-reported adherence and have not explored differences across communication domains or therapeutic indications.

METHODS

To investigate associations between patient communication ratings and cardiometabolic medication refill adherence, we conducted a cross-sectional analysis of 9377 patients in the Diabetes Study of Northern California (DISTANCE), a race-stratified, random sample of Kaiser Permanente survey respondents. Eligible participants received 1 or more oral hypoglycemic, lipid-lowering, or antihypertensive medication in the 12 months preceding the survey. Communication was measured with a 4-item Consumer Assessment of Healthcare Providers and Systems Survey (CAHPS) score and 4 items from the Trust in Physicians and Interpersonal Processes of Care instruments. Poor adherence was classified as greater than a 20% continuous medication gap for ongoing medication therapies. Using modified least squares regression, we calculated differences in poor adherence prevalence for a 10-point decrease in CAHPS score and compared higher vs lower communication ratings on other items, adjusting for necessary sociodemographic and medical confounders derived from a directed acyclic graph.

RESULTS

In this cohort, 30% had poor cardiometabolic medication refill adherence. For each 10-point decrease in CAHPS score, the adjusted prevalence of poor adherence increased by 0.9% (P=.01). Compared with patients offering higher ratings, patients who gave health care providers lower ratings for involving patients in decisions, understanding patients' problems with treatment, and eliciting confidence and trust were more likely to have poor adherence, with absolute differences of 4% (P=.04), 5% (P=.02), and 6% (P=.03), respectively. Associations between communication and adherence were somewhat larger for hypoglycemic medications than for other medications.

CONCLUSIONS

Poor communication ratings were independently associated with objectively measured inadequate cardiometabolic medication refill adherence, particularly for oral hypoglycemic medications. Future studies should investigate whether improving communication skills among clinicians with poorer patient communication ratings could improve their patients' cardiometabolic medication refill adherence and outcomes.

Assessing barriers to medication adherence in underserved patients with diabetes in Texas

PURPOSE

The purpose of this study was to assess (1) medication adherence in individuals with diabetes, (2) barriers to adherence, and (3) what factors were related to medication nonadherence.

METHODS

A self-administered anonymous survey was provided to adults with diabetes (N = 59) who used a grocery store chain pharmacy or a community clinic for the underserved. Participants were recruited by pharmacy staff to complete a 10- to 15-minute survey to assess adherence, access, barriers, medication use, and demographics. Adherence was measured using the 8-item Morisky Medication Adherence Scale (MMAS), which is a reliable and valid self-report adherence instrument. Access (e.g., use medications from Mexico, transportation), barriers (e.g., cost, language difficulties), medication use (e.g., complementary and alternative medicine, prescription medication), and demographics were also measured. The survey was available in English and Spanish. Data collection occurred from December 2010 through February 2011.

RESULTS

Fifty-nine participants completed the survey. Approximately 57% of study participants were male, 85% were Hispanic, and the mean age was 50.4 ± 10.3 years. Over 50% of participants had hypertension or dyslipidemia and were taking 3 or more medications. Participants (52.6%) reported their health status as good or excellent and over one-half (56%) of the participants were nonadherent (score 0-6). The following factors were significantly (P < .05) related to nonadherence: cost, no refills, poor health status, fewer disease states, and any reason.

CONCLUSIONS

This study increased awareness of barriers to medication adherence in a predominantly Hispanic underserved patient population. This may lead to more informed recommendations and perhaps address gaps in health disparities.