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

Impact of pharmacist-led intervention in medication adherence and inhaler usage on asthma and chronic obstructive pulmonary disease control: a quasi-experimental study

BACKGROUND

Despite recent advances in the management of asthma and chronic obstructive pulmonary disease (COPD), patients still experience suboptimal disease control largely due to medication non-adherence and inappropriate use of inhaler. This study evaluates the impact of pharmacist-led intervention in medication adherence and inhaler usage on asthma and COPD control among out-patients attending the premier tertiary hospital in Nigeria.

METHOD

A quasi-experimental study carried-out among eligible out-patients attending pulmonology clinic of University College Hospital, Ibadan. Baseline questionnaire explored medication adherence using a comprehensive-medication-adherence-assessment-scale (CMAAS-12) developed by the study co-investigators, use of pressurized-metered-dose (pMDI) and Diskus inhalers, as well as asthma/COPD control using validated asthma control test (ACT) and COPD assessment test (CAT). Subsequently, patients were allocated into control (n = 65) or intervention group (n = 65) using odd or even number. Intervention group received 2-month follow-up educational and/or cognitive-behavioural interventions to resolve identified adherence barriers, while control group continued with traditional care. Descriptive statistics, Chi-square and Wilcoxon-signed-ranked tests were used for analysis at p < 0.05.

RESULTS

Overall, patients with optimal adherence were 11(18.6%) and 16(27.1%), p = 0.132 (control), but 20(33.3%) and 38(63.3%), p < 0.001 (intervention) at baseline and post-baseline, respectively. Specifically, in the intervention group, the identified adherence barriers at baseline were summarized into knowledge (120;40.4%), practical (115;38.7%) and attitudinal (62;20.9%). Patients with correct use of pMDI were 11(21.6%) baseline and 19(36.5%) post-baseline, p = 0.011 (control), but 13(22.8%) and 46(80.7%) respectively, p < 0.001 (intervention). Correct use of Diskus inhaler were 5(50.0%) and 4(40.0%), p = 0.157 (control), but 7(35.0%) and 14(70.0%), p = 0.025 (intervention) at baseline and post-baseline, respectively. Patients with 'well-controlled asthma' were 25(44.6%) and 26 (47.3%), p = 0.025 (control), but 18(35.3%) and 32(60.4%), p < 0.001 (intervention) at baseline and post-baseline, respectively. The COPD-specific health status indicated that 0(0.0%) and 1(14.3%), p = 0.059 (control), but 0(0.0%) and 7(50.0%), p < 0.001 (intervention) at baseline and post-baseline, respectively, belonged to 'low COPD impact'.

CONCLUSION

Pharmacist-led intervention significantly enhanced medication adherence and appropriate use of inhaler among the intervention cohort, with subsequent significant improvement in asthma control and reduced COPD impact compared with the control group. This underscores the need for active involvement of pharmacists in collaborative management of patients with chronic respiratory diseases in clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT06417931. Retrospectively-registered.

A phase 4 randomized active-controlled clinical study to compare the efficacy and safety of sustained-release pregabalin with immediate-release pregabalin in type 2 diabetic patients with peripheral neuropathic pain

AIMS

The objective of this study was to demonstrate that sustained-release (SR) pregabalin is non-inferior to immediate-release (IR) pregabalin in attenuating diabetic peripheral neuropathic (DPN) pain along with patient satisfaction and compliance.

METHODS

This was an 8-week, randomized, active-controlled, open-label, phase 4 study. Eligible subjects who had been on IR pregabalin for 4 weeks were randomized to 1:1 ratio to either continue with twice-daily IR pregabalin (75 mg), or to switch to once-daily SR pregabalin (150 mg). Primary efficacy endpoint was the change in visual analogue scale (VAS) scores after 8 weeks of treatment compared to baseline in both SR and IR pregabalin groups.

RESULTS

Among 130 randomized subjects, 125 patients were included in full analysis set. For the change in VAS pain score, the least squares (LS) mean were -17.95 (SR pregabalin) and -18.74 (IR pregabalin) and the LS mean difference between both groups was 0.79, with the upper limit of the 95 % confidence interval [-5.99, 7.58] below the pre-specified non-inferiority margin of 9.2 mm.

CONCLUSIONS

This study demonstrates that the new once-daily SR pregabalin formulation is not different to the twice-daily IR pregabalin in alleviating DPN pain, indicating its potential as a promising treatment for DPN pain with a comparable safety profile.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05624853.

Evaluating A Multicomponent Chronic Disease Management Pilot Intervention among Korean Patients with Hypertension and Diabetes

Background

A local clinic-based chronic disease management intervention including care planning, education about disease management, monitoring, and evaluation of the achievement of objects was introduced in Korea in 2019. We evaluated the effect of the intervention on medication adherence in patients with hypertension and diabetes.

Methods

In 2019, a one-year retrospective case-control group study design was performed using data from the National Health Insurance Service in Korea. Propensity score matching was used to control for selection bias. Medication adherence, calculated by medication possession rate, was the dependent variable. We conducted multivariate logistic regression analyses to examine the association between participation in the intervention and medication adherence, adjusting for covariates. A control group was set as a reference for participation in the full/partial component intervention.

Results

The proportions of participants in the full component intervention in the experimental group were 43.2% and 42.6% for patients with hypertension or diabetes, respectively. Both these groups tended to be more medication adherent than their counterparts (hypertension OR: 1.23, 95% CI 1.03-1.45, diabetes OR: 1.64, 95% CI: 1.24-2.17).

Conclusion

Institutionalizing a comprehensive chronic disease management program using multidisciplinary teams in the primary care context is crucial. Also, it is necessary to refine reimbursement payment systems.

Validity, sensitivity and specificity of a measure of medication adherence instrument among patients taking oral anticoagulants

Although self-report instruments are currently considered a valuable tool for measuring adherence, due to their low cost and ease of implementation, there are still important factors that impact measurement accuracy, such as social desirability and memory bias. Thus, the Global Assessment of Medication Adherence Instrument (GEMA) was developed to provide an accurate measure of this construct. The aim of this study was to evaluate the properties of the measurement of the Global Evaluation of Medication Adherence Instrument (GEMA) among patients with chronic diseases. A methodological study was conducted in the public hospital of the state of São Paulo, Brazil. The adherence to anticoagulants as well as the international normalized ratio (INR) was assessed on 127 patients. Besides GEMA, two other instruments were used to assess adherence: the Morisky Medication Adherence Scale-8 (MMAS-8) and the Measurement of Adhesion to Treatments (MAT). The GEMA presented a satisfactory level of specificity (0.76) to identify adherents among those with a stable INR, low sensitivity (0.43) for the identification of non-adherents among those with an unstable INR, and a Positive Predictive Value of 0.70. Positive and weak to moderate correlations were observed between the proportion of doses assessed with GEMA and the scores on the MMAS-8 (r = .26 and r = .22, respectively) and the MAT (r = .22 and r = .30, respectively). The GEMA presented good practicality, acceptability, and evidence of specificity regarding the stability of the INR. The validity of the construct was partially supported by the relationship with self-reported measures of adherence.

Quality of measurement properties of medication adherence instruments in cardiovascular diseases and type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Medication adherence has a major impact on reducing mortality and healthcare costs related to the treatment of cardiovascular diseases and diabetes mellitus. Selecting the best patient-reported outcome measure (PROM) among the many available for this kind of patient is extremely important. This study aims to critically assess, compare and synthesize the quality of the measurement properties of patient-reported outcome measures to assess medication adherence among patients with cardiovascular diseases and/or type 2 diabetes mellitus.

METHODS

This review followed the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines and was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). The searches were performed in Web of Science, SCOPUS, PubMed, CINAHL, EMBASE, LILACS, PsycINFO, and ProQuest (gray literature).

RESULTS

A total of 110 records encompassing 27 different PROMs were included in the review. The included records were published between 1986 and 2023, most of which reported studies conducted in the United States and were published in English. None of the PROMs were classified in the category "a", thus being recommended for use due to the quality of its measurement properties. The PROMs that should not be recommended for use (category "c") are the MTA, GMAS, DMAS-7, MALMAS, ARMS-D, and 5-item questionnaire. The remaining PROMs, e.g., MMAS-8, SMAQ, MEDS, MNPS, ARMS-12, MGT, MTA-OA, MTA-Insulin, LMAS-14, MARS-5, A-14, ARMS-10, IADMAS, MAQ, MMAS-5, ProMAS, ARMS-7, 3-item questionnaire, AS, 12-item questionnaire, and Mascard were considered as having the potential to be recommended for use (category "b").

CONCLUSION

None of the included PROMs met the criteria for being classified as trusted and recommended for use for patients with cardiovascular diseases and/or type 2 diabetes mellitus. However, 21 PROMs have the potential to be recommended for use, but further studies are needed to ensure their quality based on the COSMIN guideline for systematic reviews of PROMs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019129109.

Test performance of self-report adherence tools in patients with hypertension: A systematic review and a meta-analysis

WHAT IS KNOWN AND OBJECTIVES

Adherence has proved to have a positive influence on achieving plausible treatment outcomes. Self-report questionnaires are widely used in evaluating adherence, creating thus a high-powered research field. This review aims to provide an update of scales used in hypertension, which are compared and analysed against reliability and validity.

METHODS

PubMed, Web of Science and Cochrane Library were searched in May 2022 to identify studies. We extracted the study characteristics and evaluated their quality. A random-effects model with subgroup analysis was used to calculate estimates and heterogeneity parameters as well as regressions, funnel and forest plots. A bivariate model was selected to conduct validity analyses and draw receiver operating characteristic (ROC) curves.

RESULTS AND DISCUSSION

Fifty-five articles were identified and classified into 22 different reliable and validated tools. Pooled analyses predicted an overall good Cronbach's alpha of 0.76 (95%CI:0.67-0.83), a good ICC of 0.8 (95%CI:0.72-0.86) and an excellent correlation coefficient of 0.91 (95%CI:0.86-0.95), which all showed high heterogeneity and slight detection of asymmetry. Regression analyses showed that only time and the number of items/scale type influenced significantly retest and alpha, respectively. Overall validity showed acceptable sensitivity of 0.65 (95%CI:0.53-0.75) and specificity of 0.57 (95%CI:0.47-0.67) with a good Area Under Curve (AUC) of 0.637. Upon comparison, four tools showed superiority over Morisky's scale.

WHAT IS NEW AND CONCLUSION

Adherence is a multi-dimensional phenomenon, which deems scales to be highly variable or complex; thus, complicating the selection process. Adherence to Refills and Medications Scale (ARMS) is the most promising free non-inferior alternative to Morisky, the most used scale.

Measurement Properties of Patient-Reported Outcome Measures for Medication Adherence in Cardiovascular Disease: A COSMIN Systematic Review

BACKGROUND AND OBJECTIVE

Several medication adherence patient-reported outcome measures (MA-PROMs) are available for use in patients with cardiovascular disease (CVD); however, little evidence is available on the most suitable MA-PROM to measure medication adherence in patients with CVD. The aim of this systematic review is to synthesise the measurement properties of MA-PROMs for patients with CVD and identify the most suitable MA-PROM for use in clinical practice or future research in patients with CVD.

METHODS

An electronic search of nine databases (PubMed, MEDLINE, CINAHL, ProQuest Health and Medicine, Cochrane Library, PsychInfo, Scopus, Embase, and Web of Science) was conducted to identify studies that have reported on at least one of the measurement properties of MA-PROMs in patients with CVD. The methodological quality of the studies included in the systematic review was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist.

RESULTS

A total of 40 MA-PROMs were identified in the 84 included studies. This review found there is a lack of moderate-to-high quality evidence of sufficient content validity for all MA-PROMs for patients with CVDs. Only eight MA-PROMs were classified in COSMIN recommendation category A. They exhibited sufficient content validity with very low-quality evidence, and moderate-to-high quality evidence for sufficient internal consistency. The 28 MA-PROMs that meet the requirements for COSMIN recommendation category 'B' require further validation studies. Four MA-PROMs including Hill-Bone Compliance Medication Scale (HBMS), the five-item Medication Adherence Report Scale (MARS-5), Maastricht Utrecht Adherence in Hypertension (MUAH), and MUAH-16 have insufficient results with high quality evidence for at least one measurement property and consequently are not recommended for use in patients with CVD. Two MA-PROMs (Adherence to Refills and Medications Scale [ARMS] and ARMS-7) are comprehensive and have moderate to high quality evidence for four sufficient measurement properties.

CONCLUSION

From the eight MA-PROMs in COSMIN recommendation category A, ARMS and ARMS-7 were selected as the most suitable MA-PROMs for use in patients with CVD. They are the most comprehensive with be best quality evidence to support their use in clinical practice and research.

Global Burden, Regional Differences, Trends, and Health Consequences of Medication Nonadherence for Hypertension During 2010 to 2020: A Meta-Analysis Involving 27 Million Patients

Background

Nonadherence to antihypertensive medications is the leading cause of poor blood pressure control and thereby cardiovascular diseases and mortality worldwide.

Methods and Results

We investigated the global epidemiology, regional differences, and trend of antihypertensive medication nonadherence via a systematic review and meta‐analyses of data from 2010 to 2020. Multiple medical databases and clinicaltrials.gov were searched for articles. Observational studies reporting the proportion of patients with anti‐hypertensive medication nonadherence were included. The proportion of nonadherence, publication year, year of first recruitment, country, and health outcomes attributable to antihypertensive medication nonadherence were extracted. Two reviewers screened abstracts and full texts, classified countries according to levels of income and locations, and extracted data. The Joanna Briggs Institute prevalence critical appraisal tool was used to rate the included studies. Prevalence meta‐analyses were conducted using a fixed‐effects model, and trends in prevalence were analyzed using meta‐regression. The certainty of evidence concerning the effect of health consequences of nonadherence was rated according to Grading of Recommendations, Assessment, Development and Evaluations. A total of 161 studies were included. Subject to different detection methods, the global prevalence of anti‐hypertensive medication nonadherence was 27% to 40%. Nonadherence was more prevalent in low‐ to middle‐income countries than in high‐income countries, and in non‐Western countries than in Western countries. No significant trend in prevalence was detected between 2010 and 2020. Patients with antihypertensive medication nonadherence had suboptimal blood pressure control, complications from hypertension, all‐cause hospitalization, and all‐cause mortality.

Conclusions

While high prevalence of anti‐hypertensive medication nonadherence was detected worldwide, higher prevalence was detected in low‐ to middle‐income and non‐Western countries. Interventions are urgently required, especially in these regions. Current evidence is limited by high heterogeneity.

Registration

URL: www.crd.york.ac.uk/prospero/; Unique identifier: CRD42021259860.

Development and validation of a questionnaire to determine medical orders non-adherence: a sequential exploratory mixed-method study

Background

Patients’ non-adherence with medical orders of physicians in outpatient clinics can lead to reduced clinical effectiveness, inadequate treatment, and increased medical care expenses. This study was conducted to develop and validate a questionnaire to determine the reasons for patients’ non-adherence with physicians’ medical orders.

Methods

A sequential exploratory mixed-method study was conducted in two stages. The first stage comprised a qualitative stage to generate the primary items of the questionnaire. This stage provided findings of two sub-stages comprising a literature review and the findings of a qualitative conventional content analysis of 19 semi-structured interviews held with patients, physicians, and managers of the outpatient clinics in Kerman, an area located in southeastern Iran. The second stage comprised a quantitative study aiming evaluation of the instrument psychometric properties, including the face, content, construct, and reliability assessment of the questionnaire. Construct validity assessment was evaluated using exploratory factor analysis (EFA). The reliability assessment was done using assessing internal consistency (Cronbach’s alpha). To assess the construct validity of the questionnaire, four hundred and forty patients referred to outpatient clinics in Kerman were selected using stratified convenience sampling to fill out the questionnaire. The sample size was calculated using the Cochran formula. Qualitative and quantitative data were analyzed by MAXQDA 10 and Stata version 14, respectively.

Results

The primary items contained 57 items, of which 42 met the minimum acceptable value of 0.78 for item-level content validity index (I-CVI = 1 for 24 items and I-CVI = 0.8 for 18 items). Item-level content validity ratio (I-CVR) was confirmed for 18 items with a minimum acceptable value of 0.99 for five experts. Finally, 18 items obtained the acceptable value for both I-CVI and I-CVR indicators and were confirmed. Using EFA, four factors (intrapersonal-psychological, intrapersonal-cognitive, provider-related, and socio-economic reasons) with 18 items and Cronbach’s alpha coefficient of 0.70, 0.66, 0.73, and 0.71, respectively, were identified and explained 51% of the variance. The reliability of the questionnaire (r = 0.70) was confirmed.

Conclusion

The questionnaire with four dimensions is a valid and reliable instrument that can help determine the perceived reasons for non-adherence with medical orders in the outpatient services system.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06147-3.

The psychometric properties of the Hypertensive Treatment Adherence Scale

BACKGROUND

Hypertension (HTN) is a public concern and treatment adherence has a key role in its management. This study was conducted to develop and test the reliability and validity of the Hypertensive Treatment Adherence scale (HTA-scale).

METHODS

This was a cross-sectional and methodological study. After item generation using a qualitative study and literature review, the scale was developed. The psychometric properties of the scale were evaluated using face, content, construct, and criterion validity and reliability.

RESULTS

Data analysis showed that the HTA-scale had acceptable face and content validity. The scale had excellent stability [Intraclass correlation coefficient (ICC) = 0.74] and good acceptability and internal consistency (Cronbach's a = 0.76). Exploratory factor analysis (EFA) showed that the HTA-scale consisted of 6 meaningful subscales including medication adherence and monitoring, adherence to safe diets, avoiding unsafe diets, self-medication, activity, and smoking. Participants in the controlled blood pressure group had significantly higher HTA-scale scores than the uncontrolled blood pressure group. At the cut-off point of 86, the scale had significant sensitivity and specificity.

CONCLUSION

All of the psychometric properties of the HTA-scale achieved the standard level and were sufficient to recommend this scale for patients with HTN.

Measurement Properties of Existing Patient-Reported Outcome Measures on Medication Adherence: Systematic Review

BACKGROUND

Medication adherence is essential for improving the health outcomes of patients. Various patient-reported outcome measures (PROMs) have been developed to measure medication adherence in patients. However, no study has summarized the psychometric properties of these PROMs to guide selection for use in clinical practice or research.

OBJECTIVE

This study aims to evaluate the quality of the PROMs used to measure medication adherence.

METHODS

This study was guided by the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. Relevant articles were retrieved from the EMBASE, PubMed, Cochrane Library, Web of Science, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases. The PROMs were then evaluated based on the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidelines.

RESULTS

A total of 121 unique medication adherence PROMs from 214 studies were identified. Hypotheses testing for construct validity and internal consistency were the most frequently assessed measurement properties. PROMs with at least a moderate level of evidence for ≥5 measurement properties include the Adherence Starts with Knowledge 20, Compliance Questionnaire-Rheumatology, General Medication Adherence Scale, Hill-Bone Scale, Immunosuppressant Therapy Barrier Scale, Medication Adherence Reasons Scale (MAR-Scale) revised, 5-item Medication Adherence Rating Scale (MARS-5), 9-item MARS (MARS-9), 4-item Morisky Medication Adherence Scale (MMAS-4), 8-item MMAS (MMAS-8), Self-efficacy for Appropriate Medication Adherence Scale, Satisfaction with Iron Chelation Therapy, Test of Adherence to Inhalers, and questionnaire by Voils. The MAR-Scale revised, MMAS-4, and MMAS-8 have been administered electronically.

CONCLUSIONS

This study identified 121 PROMs for medication adherence and provided synthesized evidence for the measurement properties of these PROMs. The findings from this study may assist clinicians and researchers in selecting suitable PROMs to assess medication adherence.

Development of an Item Bank to Measure Medication Adherence: Systematic Review

Background

Medication adherence is important in managing the progression of chronic diseases. A promising approach to reduce cognitive burden when measuring medication adherence lies in the use of computer‐adaptive tests (CATs) or in the development of shorter patient-reported outcome measures (PROMs). However, the lack of an item bank currently hampers this progress.

Objective

We aim to develop an item bank to measure general medication adherence.

Methods

Using the preferred reporting items for systematic review and meta-analysis (PRISMA), articles published before October 2019 were retrieved from PubMed, Embase, CINAHL, the Cochrane Library, and Web of Science. Items from existing PROMs were classified and selected (“binned” and “winnowed”) according to standards published by the Patient-Reported Outcomes Measurement Information System (PROMIS) Cooperative Group.

Results

A total of 126 unique PROMs were identified from 213 studies in 48 countries. Items from the literature review (47 PROMs with 579 items for which permission has been obtained) underwent binning and winnowing. This resulted in 421 candidate items (77 extent of adherence and 344 reasons for adherence).

Conclusions

We developed an item bank for measuring general medication adherence using items from validated PROMs. This will allow researchers to create new PROMs from selected items and provide the foundation to develop CATs.

Beliefs and attitudes toward endocrine therapy in patients with hormone receptor-positive breast cancer

Patients' beliefs about medications are important predictors of medication adherence; however, the relationship between patient beliefs and adjuvant endocrine therapy (AET) adherence in patients with breast cancer remains unclear. In this study, we aimed to determine the association between patient beliefs and adherence to AET. Self-reported questionnaires covering necessity beliefs (NB), concerns beliefs (CB), and adherence were completed by 210 Korean patients with breast cancer. The rate of nonadherence was determined by calculating necessity-concern (N-C) differentials and attitudinal subgroup analysis. Multivariate logistic regression analysis was performed to determine the independent impact of patient beliefs on nonadherence. Nonadherence (Morisky Medication Adherence Scale < 8) was reported in 74.3% (n = 156) of patients and predicted by a negative balance regarding AET [odds ratio (OR) = 0.89; 95% confidence interval (CI): 0.83-0.96] and strong concerns about AET such as those in the Ambivalent (OR = 5.41; 95% CI: 1.84-15.92) and Skeptical (OR = 3.48, 95% CI: 1.14-10.65) subgroups. Patient beliefs are significantly associated with adherence to AET in Korean patients with breast cancer. NB, CB, and N-C differentials may be useful intervention targets to improve medication adherence.

Questionnaires on adherence to antihypertensive treatment: a systematic review of published questionnaires and their psychometric properties

Background Non-adherence to antihypertensive treatment is currently considered one of the most significant risk factors in failure to achieve controlled blood pressure values. It is therefore extremely important to measure patient adherence to antihypertensive treatment. One way to measure adherence is through questionnaires. Numerous questionnaires for measuring adherence to antihypertensive treatment have been validated, but it not easy to choose one of them as being more appropriate than all of the others. Aim of the review The aim of this study was to identify and assess questionnaires designed to measure non-adherence to antihypertensive treatment, and to discuss their psychometric properties. Method A systematic review of the literature contained in PubMed and Scopus databases was undertaken to identify validated questionnaires on adherence to antihypertensive treatment up to October 2017. PRISMA guidelines were followed to conduct and report this review. Selection of articles and data extraction were performed by two independent researchers. When there was lack of agreement, a third researcher mediated in the discussion between the first two authors so that consensus could be reached. Results 39 articles were obtained containing 17 different questionnaires for measuring adherence to antihypertensive treatment. These questionnaires were validated in 15 countries. The number of items in the questionnaires ranged from three in QAM-Q to 33 in TAQPH. Hill-Bone compliance to high blood pressure therapy scale, Morisky-Green-Levine test and an 8-item Self-Reported Medication Adherence Measurement were the most widely validated questionnaires. Validity was analyzed more than reliability. Many of the questionnaires do not provide information on content validity. Construct validity and concurrent validity are analyzed in almost all of the questionnaires, and give highly variable results. By contrast, known-groups validity was not analyzed to any great degree. As regards reliability, almost all of the questionnaires provided Cronbach's alpha information with reasonably acceptable results, but temporal stability was not analyzed to any great degree. Conclusion None of the questionnaires included in the review demonstrates fulfilling all of the validity tests (content validity, construct validity and criterion-related validity) and reliability tests (homogeneity and temporal stability) in an acceptable manner. Therefore, none of them can be considered a Gold Standard.

Association between medication adherence and quality of life of patients with diabetes and hypertension attending primary care clinics: a cross-sectional survey

PURPOSE

To evaluate the association between medication adherence and quality of life (QoL) of patients with diabetes and/or hypertension attending primary care clinics.

METHODS

In this cross-sectional study, patients with at least one long-term condition (hypertension or diabetes mellitus) meeting the eligibility criteria were recruited from five primary care clinics in Saudi Arabia. Arabic version of Morisky Medication Adherence Scale (MMAS-8) and the World Health Organization Quality of Life-BREF (WHOQOL-BREF) tool were used to assess medication adherence and QoL, respectively. Patients' sociodemographic, medical and medication data were collected using a structured, pilot-tested data collection form.

RESULTS

Three hundred patients with a mean (± SD) age of 56.79 (12.8) years participated in the study. Fifty-eight had hypertension only, 96 had diabetes (Type 1 or 2), and 146 had both hypertension and diabetes. After adjusting for socioeconomic characteristics, multiple linear regression analysis found that adherent patients had significantly higher mean overall perception of QoL and health scores by 14.6 (P = 0.001) and 17.2 (P = 0.001) points, respectively, compared to non-adherent patients. In addition, irrespective of the type of long-term condition, adherence status was found to be an independent predictor of all QoL domains.

CONCLUSION

There is an association between medication adherence and QoL among patients with diabetes and/or hypertension attending primary care clinics. Medication adherence should be assessed and emphasised during routine clinical consultations in primary care in order to achieve the desired clinical outcomes and overall well-being of patients.

Cross-cultural adaptation and validation of a European Portuguese version of the 8-item Morisky medication adherence scale

INTRODUCTION AND OBJECTIVE

The 8-Item Morisky Medication Adherence Scale (MMAS-8) is one of the most widely used instruments to assess medication adherence, but a validated European Portuguese version of MMAS-8 does not exist. Our aim was to develop and validate a European Portuguese version of the MMAS-8.

METHODS

A process of translation and back-translation of the original MMAS-8 was performed. The questionnaire was administered in nine community pharmacies and one public hospital between March 2014 and September 2015. Adult patients taking at least one antihypertensive drug were invited to participate. A confirmatory factor analysis was performed and internal consistency, convergent validity and concurrent validity were examined.

RESULTS

A total of 472 patients were enrolled in the study. The mean MMAS-8 score obtained was 6.74±1.39. One hundred and thirty-two patients were classified as low adherers (28%), 181 (38.3%) as medium adherers and 159 (33.7%) as high adherers. For the factorial structure of the Portuguese version of the MMAS-8, the fit indices of the final model (chi-square [18] 48.465, p<0.001) are suggestive of very good fit, with comparative fit index 0.95, root mean square error of approximation 0.06 (90% confidence interval 0.04-0.08), and standardized root mean square residual 0.04, confirming that the construct tested was unidimensional. The Cronbach's alpha for all items was 0.60, and the translated version presents convergent validity and concurrent validity.

CONCLUSION

A European Portuguese version of the MMAS-8 was created that maintained a similar structure to the original MMAS-8 and good psychometric properties.

Nonadherence to antihypertensive drugs: A systematic review and meta-analysis

BACKGROUND

Hypertension drives the global burden of cardiovascular disease and its prevalence is estimated to increase by 30% by the year 2025. Nonadherence to chronic medication regimens is common; approximately 43% to 65.5% of patients who fail to adhere to prescribed regimens are hypertensive patients. Nonadherence to medications is a potential contributing factor to the occurrence of concomitant diseases.

OBJECTIVE

This systematic review applied a meta-analytic procedure to investigate the medication nonadherence in adult hypertensive patients.

METHODS

Original research studies, conducted on adult hypertensive patients, using the 8-item Morisky medication adherence scale (MMAS-8) to assess the medication adherence between January 2009 and March 2016 were included. Comprehensive search strategies of 3 databases and MeSH keywords were used to locate eligible literature. Study characteristics, participant demographics, and medication adherence outcomes were recorded. Effect sizes for outcomes were calculated as standardized mean differences using random-effect model to estimate overall mean effects.

RESULTS

A total of 28 studies from 15 countries were identified, in total comprising of 13,688 hypertensive patients, were reviewed. Of 25 studies included in the meta-analysis involving 12,603 subjects, a significant number (45.2%) of the hypertensive patients and one-third (31.2%) of the hypertensive patients with comorbidities were nonadherent to medications. However, a higher proportion (83.7%) of medication nonadherence was noticed in uncontrolled blood pressure (BP) patients. Although a higher percentage (54%) of nonadherence to antihypertensive medications was noticed in females (P < 0.001), the risk of nonadherence was 1.3 times higher in males, with a relative risk of 0.883. Overall, nearly two-thirds (62.5%) of the medication nonadherence was noticed in Africans and Asians (43.5%).

CONCLUSION

Nonadherence to antihypertensive medications was noticed in 45% of the subjects studied and a higher proportion of uncontrolled BP (83.7%) was nonadherent to medication. Intervention models aiming to improve adherence should be emphasized.

Medication Adherence Improvement By Using Administration Timing Simplification Protocol (ATSP) in Cardiovascular Disease Patients

Aims: In chronic diseases, keeping adherence to medication is very difficult. The objective of this study was to evaluate the impact of administration timing simplification protocol (ATSP) on medication adherence and clinical parameters of cardiovascular diseases.

Methods: 210 out-patients with cardiovascular disease, who were taking two or more pills of any type of medication per day for more than one year, were enrolled and randomized. The intervention group followed the simplified administration schedule of ATSP with two main strategies: 1) moving medication from “pc” (30 minute after meal) to “stat. pc” (immediately after meal); and 2) moving medication time from “at evening” to “at morning.” In contrast, the control group maintained the same medication schedule. Both patient groups were equally educated about the names and effects of the medication.

Results: The intervention group had more pills than the control group with marginal statistical significance (5.1 ± 2.3 vs 4.6 ± 1.8, p = 0.05). The total frequency of administration was significantly higher in the intervention group than that of the control group (2.9 ± 1.0 vs 2.6 ± 0.9, p = 0.03) at the baseline. In the intervention group, the frequency was significantly decreased to 1.5 ± 0.6 times per day after following ATSP application (p < 0.01). In both patient groups, knowledge about the medication was significantly improved by education. However, medication adherence was only improved in the intervention group. Interestingly, total cholesterol was significantly decreased in the intervention group (p < 0.01). The decrease in serum cholesterol concentration was significantly correlated with the improvement in medication adherence evaluated with Morisky Medication Adherence Scale (MMAS)-8 items (r = 0.507, p < 0.01).

Conclusion: ATSP was shown to be an effective strategy to improve medication adherence in chronic cardiovascular disease patients.

Evaluation of the Measurement Properties of Self-reported Medication Adherence Instruments Among People at Risk for Metabolic Syndrome: A Systematic Review

PURPOSE

The purpose of this study was to present a systematic review of available published studies that evaluated the measurement properties of self-reported instruments assessing global medication adherence in adults at risk for metabolic syndrome.

METHODS

The authors searched PubMed, EMBASE, PsycINFO, and CINAHL in January 2015 for appropriate studies. The methodological quality (based on reliability, validity, responsiveness, and interpretability) of selected studies was assessed with the COSMIN checklist (Consensus-Based Standards for the Selection of Health Measurement Instruments).

RESULTS

Of the 44 studies reviewed, 32 used classical test theory, and 14 used self-reported medication adherence instruments. More than half the studies included patients with hypertension, followed by diabetes, dyslipidemia, and increased body mass index. Among the measurement properties, internal consistency, hypothesis testing, and structural validity were frequently assessed items, whereas only 1 study evaluated responsiveness, and none evaluated measurement error. The MMAS-8 (Morisky Medication Adherence Scale-8 items) and the Hill-Bone scale were the most frequently used instruments. They were found to be well validated, with strong evidence for internal consistency and strong positive evidence for reliability, structural validity, hypothesis testing, and criterion validity.

CONCLUSIONS

The MMAS-8 and Hill-Bone scale seem to be well-validated instruments for assessing medication adherence in adults at risk for metabolic syndrome. These findings may assist clinicians with selecting the appropriate instruments for assessing medication adherence in this population. However, further studies might be needed to define concepts to better understand the dimensions of each medication adherence instrument.

Factors Associated With Medication Adherence Among Medical-Aid Beneficiaries With Hypertension

The purpose was to examine factors associated with medication adherence among medical-aid beneficiaries with hypertension using the Expanded Behavioral Model of Health Services Utilization. A cross-sectional study was conducted with a convenient sample of 289 patients. The instruments included scales to measure medication adherence, health literacy, general self-efficacy, and pros and cons of chronic disease management. Data collection was performed between February and March 2011. A hierarchical regression analysis was performed. The study found that 25.6% to 34.6% had low motivation and low knowledge regarding medication adherence. Those with higher health literacy and higher self-efficacy scores were more likely to have higher medication adherence, whereas widowed and those who perceived more cons of chronic disease management were more likely to have lower medication adherence than their counterparts (p < .05). Interventions incorporating significant factors associated with medication adherence are required to enhance medication adherence and to prevent complications associated with medication non-adherence.

Development and psychometric testing of the medication taking behavior tool in Thai patients

BACKGROUND

The previous Thai version of the 8-item Morisky Medication Adherence Scale (8-item MMAS) showed poor sensitivity and unacceptable internal consistency reliability.

OBJECTIVES

To develop and test the psychometric properties of a new medication taking behavior measure for Thai patients (MTB-Thai) including practicality, reliability and validity.

METHODS

This study was conducted with adult outpatients regularly taking any medicines for at least three months from three university hospitals in Bangkok, Thailand, between July 2014 and March 2015. The study was approved by the Ethical Committees of the three hospitals. Practicality was assessed by administration time and the percentage of missing data. Internal consistency and test-retest reliability were evaluated employing Cronbach's alpha and intraclass correlation coefficients (ICCs), respectively. Validity was evaluated with content, construct, convergent and known-groups validity.

RESULTS

Of 1156 patients, the 6-item MTB-Thai had an average administration time of 2 min and no missing data. It showed good Cronbach's alpha value of 0.76 and excellent ICCs of 0.83. The MTB-Thai showed good content validity with the item level and scale level of content validity indexes greater than the acceptable levels of 0.8 and 0.9, respectively. Both exploratory and confirmatory factor analyses showed the MTB-Thai had two domains including unintentional and intentional domains. The MTB-Thai correlated well with the overall medication adherence scale with a Pearson's correlation coefficient of 0.62 (p < 0.001). The sensitivity, specificity, positive predictive value and negative predictive value of the MTB-Thai were 76, 35, 55 and 57 %, respectively.

CONCLUSION

The MTB-Thai was practical, reliable and valid in assessing mediation taking behaviors in Thai patients with chronic diseases.

Why item response theory should be used for longitudinal questionnaire data analysis in medical research

BACKGROUND

Multi-item questionnaires are important instruments for monitoring health in epidemiological longitudinal studies. Mostly sum-scores are used as a summary measure for these multi-item questionnaires. The objective of this study was to show the negative impact of using sum-score based longitudinal data analysis instead of Item Response Theory (IRT)-based plausible values.

METHODS

In a simulation study (varying the number of items, sample size, and distribution of the outcomes) the parameter estimates resulting from both modeling techniques were compared to the true values. Next, the models were applied to an example dataset from the Amsterdam Growth and Health Longitudinal Study (AGHLS).

RESULTS

The results show that using sum-scores leads to overestimation of the within person (repeated measurement) variance and underestimation of the between person variance.

CONCLUSIONS

We recommend using IRT-based plausible value techniques for analyzing repeatedly measured multi-item questionnaire data.

Validation of the short-form Health Literacy Scale in patients with stroke

OBJECTIVE

We aimed to validate a Mandarin version of the short-form Health Literacy Scale (SHEAL) in patients with stroke.

METHODS

Each patient with stroke was interviewed with the SHEAL. The Public Stroke Knowledge Quiz (PSKQ) was administered as a criterion for examining the convergent validity of the SHEAL. The discriminative validity of the SHEAL was determined with age and education level as independent grouping variables.

RESULTS

A total of 87 patients with stroke volunteered to participate in this prospective study. The SHEAL demonstrated sufficient internal consistency reliability (alpha=0.82) and high correlation with the PSKQ (r=0.62). The SHEAL scores between different age groups and education level groups were significantly different. The SHEAL, however, showed a notable ceiling effect (24.1% of the participants), indicating that the SHEAL cannot differentiate level of health literacy between individuals with high health literacy.

CONCLUSION

The internal consistency reliability, convergent validity, and discriminative validity of the SHEAL were adequate. However, the internal consistency reliability and ceiling effect of the SHEAL need to be improved.

PRACTICE IMPLICATIONS

The SHEAL has shown its potential for assessing the health literacy of patients with stroke for research purposes. For clinical usage, however, the SHEAL should be used with caution.

Psychometric properties of the eight-item Morisky Medication Adherence Scale (MMAS-8) in a psychiatric outpatient setting

The eight-item Morisky Medication Adherence Scale (MMAS-8) is a structured self-report measure of medication-taking behavior that has been widely used in various cultures. In Spain, no studies to date have analyzed the psychometric properties of the scale in psychiatric care. The purpose of the present instrumental study was to determine the psychometric properties of the Spanish version of the MMAS-8 in a sample of 967 consecutive psychiatric outpatients. The scale showed adequate construct validity and results pointed to a one-factor solution in which all the items contributed to the final index of adherence. The MMAS-8 exhibited significant correlation coefficients with the 10-item Drug Attitude Inventory, Form C of the Multidimensional Health Locus of Control scale, and the Hong Psychological Reactance Scale. Moreover, the MMAS-8 was able to differentiate between various mental disorder diagnosis groups. The findings of this study suggest that the Spanish version of the MMAS-8 is a reliable and valid measure of medication adherence that can be used in a psychiatric outpatient setting.

Self-reported adherence by MARS-CZ reflects LDL cholesterol goal achievement among statin users: validation study in the Czech Republic

RATIONALE, AIMS AND OBJECTIVES

Measuring self-reported adherence may contribute to minimizing the risk of therapy failure. Hence, the main aim of the study was to assess the psychometric properties of the Czech version of Medication Adherence Report Scale (MARS-CZ) and its appropriateness for use in long-term statin therapy where goal levels of low-density lipoprotein cholesterol (LDL-c) should be achieved.

METHODS

Anonymous structured interview was performed to determine self-reported adherence by MARS-CZ in outpatients chronically treated with statins. At the same time, medication records were reviewed for inclusion of patients into groups of those who achieved and do not achieved LDL-c goal according to cardiovascular risk level. Reliability and validity of MARS-CZ were tested as well as the relationship between adherence and LDL-c goal achievement was examined.

RESULTS

A total of 136 (86.6%) patients completed the interview; mean age was 66.1 years; 49.3% were male. The mean score of MARS-CZ was 24.4 and showed positive skewing. Satisfactory internal consistency (Cronbach's α=0.54), strong test-retest reliability (r=0.83, P<0.001; intra-class correlation=0.63, 95% confidence interval: 0.35-0.81) and positive correlation with eight-item Morisky Medication Adherence Scale (r=0.62, P<0.001) were indicated. Low validity values were found between MARS-CZ and 12-item Short Form Health Survey mental and physical subscales. MARS-CZ score significantly correlated with LDL-c goal achievement (P<0.05) when all patients who achieved LDL-c goal (35%) reported high adherence to statin. MARS-CZ score also correlated with cardiovascular risk level and doctor's judgments on adjusting treatment targets for each patient.

CONCLUSION

This study proved MARS-CZ as an acceptable self-reported adherence measure. In routine clinical practice, MARS-CZ could be helpful to reveal medication non-adherence before the alteration of drug regimen and thereby contributing to enhancement of statin therapy management.