Estimation of adherence to urate-lowering therapy in people living with gout using Australia's Pharmaceutical Benefits Scheme and patient-reported dosing

AIMS

The aim of this study was to estimate adherence to urate-lowering therapy (ULT), predominately allopurinol, from Australia's Pharmaceutical Benefits Scheme (PBS) claims database in association with (1) patient-reported doses and (2) World Health Organization's (WHO) defined daily doses (DDD), namely, allopurinol (400 mg/day) or febuxostat (80 mg/day).

METHODS

Proportion of days covered (PDC) was calculated in 108 Gout App (Gout APP) trial participants with at least two recorded ULT dispensings in an approximately 12-month period before provision of intervention or control apps. Adherence was defined as PDC ≥80%. We measured the correlation between the two methods of calculating PDC using a Wilcoxon signed rank test. Agreement between ULT-taking status (self-reports) and ULT-dispensed status (PBS records) was tested with Cohen's kappa (κ), and positive and negative percent agreement.

RESULTS

Allopurinol was prescribed in 93.5% of participants taking ULT. Their self-reported mean daily dose (SD) was 291 (167) mg/day. Mean PDC (SD) for allopurinol was 83% (21%) calculated using self-reported dose, and 63% (24%) using WHO's DDD. Sixty-three percent of allopurinol users were identified as adherent (PDC ≥80%) using self-reported dose. There was good agreement between self-reported ULT use and PBS dispensing claims (κ = 0.708, P < .001; positive percent agreement = 90%, negative percent agreement = 82%).

CONCLUSIONS

Participant-reported allopurinol daily doses, in addition to PBS dispensing claims, may enhance confidence in estimating PDC and adherence compared to using DDD. This approach improves adherence estimations from pharmaceutical claims datasets for medications where daily doses vary between individuals or where there is a wide therapeutic dose range.

Evaluating Pharmacist-Driven Interventions in a Primary Care Setting to Improve Proportion of Days Covered and Medication Adherence

Background: Medication nonadherence is the leading cause of poor health outcomes and increased risk of hospitalizations. Previous studies have shown that pharmacist interventions can help improve medication adherence and CMS quality measures. Objective: The purpose of this study was to examine the impact of clinical pharmacists' interventions on medication adherence and PDC scores for ACEi/ARBs, statins, and noninsulin antidiabetic medications in the primary care setting. Methods: This observational study was conducted at four primary care clinics to evaluate PDC scores pre- and post-pharmacist interventions from April 2020 to December 2020. Eligible patients were Humana Part D beneficiaries with a baseline PDC score <85%. The primary outcome of this study was to evaluate the average change in final PDC scores, and 1-month change in PDC scores following a pharmacist intervention. Secondary outcomes were number and types of adherence barriers identified, interventions provided by the pharmacist, and barriers and interventions category (pharmacy, patient or physician-related). Results: A total of 89 barriers were identified and 208 interventions were completed. A statistically significant difference in the average change of final PDC score from baseline was seen among those on ACEi/ARBs (72.5 to 78.0, p = 0.004) and statins (73.3 to 76.6, p < 0.001). Similarly, a statistically significant change was observed from baseline to 1-month PDC among those on ACEi/ARBS (72.5 to 75.4, p = 0.001) and statins (73.3 to 74.9, p < 0.001). Conclusion: Pharmacists located in a primary care setting improved medication adherence and PDC score for patients on ACEIs/ARBs and statins.

Prescribing patterns in patients with chronic obstructive pulmonary disease and atrial fibrillation

Patients with chronic obstructive pulmonary disease (COPD) had higher risk of atrial fibrillation (AF). The treatment of AF includes medicines to control heart rate and reduce the risk of stroke, and procedures such as cardioversion to restore normal heart rhythm. To reduce the stroke, patients with AF may prescribe some type of antithrombotic medication (such as warfarin, one of the new non-vitamin K antagonist oral anticoagulants [NOACs] - dabigitran, apixaban, rivoraxaban, or edoxaban) or maybe aspirin. The aim of our study was to exam the prescription pattern in patients with COPD and AF. We selected COPD population in Taiwan older than 40 years and less than 90 years old with an COPD diagnosis at least two outpatient claims or at least one inpatient claim coded and also need at least one prescription of bronchodilators. We followed this COPD cohort until they have AF and their prescription pattern. We included 267,740 patients with COPD who meet the inclusion and exclusion criteria and 6,582 patients concomitant with COPD and AF. The mean age was 75 years, and about 77% of the patients were older than 70 years. Three-fourths of patients with COPD were male. The common comorbidities were hypertension (17.58%), diabetes (7.47%), ischemic heart disease (4.66%), and dyslipidemia (3.68%). we found that most patients received aspirin which accounting for 31%, followed by coumadin (8.22%) and clopidogrel. Prescribing NOAC within 30 days after AF diagnosis was low in patients with COPD and the percentage of NOAC usage was also lower than warfarin.

Real-World Comparison of First-Line Treatment Adherence Between Single-Agent Ibrutinib and Acalabrutinib in Patients with Chronic Lymphocytic Leukemia

Purpose

Increased dosing frequency adversely affects treatment adherence and outcomes in chronic diseases; however, such data related to treatment adherence is lacking in chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). This study compared adherence between patients treated with ibrutinib (once-daily) versus acalabrutinib (twice-daily) as first-line (1L) therapy for CLL/SLL.

Patients and Methods

Specialty pharmacy electronic medical records were used to identify adults with CLL/SLL initiating 1L ibrutinib or acalabrutinib between 01/01/2018 and 11/30/2020. Adherence was measured by the proportion of days covered (PDC) and medication possession ratio (MPR) and was compared between cohorts using odds ratios (ORs) obtained from logistic regression models adjusted for baseline characteristics.

Results

Between 01/01/2018 and 11/30/2020, 1374 and 140 patients initiated ibrutinib and acalabrutinib, respectively. Based on PDC/MPR ≥80%, patients treated with once-daily ibrutinib were more likely to be adherent than those treated with twice-daily acalabrutinib (OR ranges: PDC: 1.04-1.76; MPR: 1.03-1.58). At 6 months, patients on ibrutinib had a 58-76% higher likelihood of staying adherent compared to patients on acalabrutinib (PDC: 75.9% for ibrutinib vs 63.6% for acalabrutinib, OR: 1.76, P=0.008; MPR: 76.8% vs 66.9%, OR: 1.58, P=0.036) with a similar trend noted for the entire line of treatment (LOT) (PDC: 53.0% vs 41.4%, OR: 1.53, P=0.021; MPR: 58.7% vs 47.1%, OR: 1.50, P=0.027).

Conclusion

In this real-world analysis, CLL/SLL patients initiating 1L once-daily ibrutinib had >50% higher treatment adherence than those initiating twice-daily acalabrutinib during their LOT. Given the importance of sustained adherence for disease control in CLL/SLL, dosing frequency may be an important consideration for patients and physicians.

Leveraging Electronic Health Record Technology and Team Care to Address Medication Adherence: Protocol for a Cluster Randomized Controlled Trial

BACKGROUND

Low medication adherence is a common cause of high blood pressure but is often unrecognized in clinical practice. Electronic data linkages between electronic health records (EHRs) and pharmacies offer the opportunity to identify low medication adherence, which can be used for interventions at the point of care. We developed a multicomponent intervention that uses linked EHR and pharmacy data to automatically identify patients with elevated blood pressure and low medication adherence. The intervention then combines team-based care with EHR-based workflows to address medication nonadherence.

OBJECTIVE

This study aims to describe the design of the Leveraging EHR Technology and Team Care to Address Medication Adherence (TEAMLET) trial, which tests the effectiveness of a multicomponent intervention that leverages EHR-based data and team-based care on medication adherence among patients with hypertension.

METHODS

TEAMLET is a pragmatic, cluster randomized controlled trial in which 10 primary care practices will be randomized 1:1 to the multicomponent intervention or usual care. We will include all patients with hypertension and low medication adherence who are seen at enrolled practices. The primary outcome is medication adherence, as measured by the proportion of days covered, and the secondary outcome is clinic systolic blood pressure. We will also assess intervention implementation, including adoption, acceptability, fidelity, cost, and sustainability.

RESULTS

As of May 2023, we have randomized 10 primary care practices into the study, with 5 practices assigned to each arm of the trial. The enrollment for the study commenced on October 5, 2022, and the trial is currently ongoing. We anticipate patient recruitment to go through the fall of 2023 and the primary outcomes to be assessed in the fall of 2024.

CONCLUSIONS

The TEAMLET trial will evaluate the effectiveness of a multicomponent intervention that leverages EHR-based data and team-based care on medication adherence. If successful, the intervention could offer a scalable approach to address inadequate blood pressure control among millions of patients with hypertension.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05349422; https://clinicaltrials.gov/ct2/show/NCT05349422.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/47930.

Adherence and treatment patterns of disease-specific drugs among patients with pulmonary arterial hypertension: A nationwide, new-user cohort study

Background: Pulmonary arterial hypertension (PAH) is an incurable pulmonary disease that might result in right heart failure and death. Treatment guidelines recommend upfront or sequential combination therapy for patients with PAH. Recently, several PAH-targeted medications have been approved in Taiwan. This study aimed to investigate treatment patterns and medication adherence in real-world settings. Method: This was a new-user design study on patients treated with PAH-specific medication between 1 January 2014, and 31 December 2019. Data were extracted from the National Health Insurance Research Database. Medication adherence was evaluated by the proportion of days covered (PDC). Adherence was defined as PDC ≥ .8. Statistical analyses were performed to compare the study outcomes. Logistic regression analysis was performed to identify the association between baseline characteristics and adherence. P < .05 indicated statistical significance. Results: A total of 1,900 patients with PAH were identified, and 75.3% of them were females. The mean (standard deviation (SD)) age was 57.2 (17.5) years. Only 23 (1.2%) patients began the initial combination therapy. A total of 148 (7.8%) patients switched their initial treatment to another treatment, and 159 (8.4%) patients had sequential combination therapy. The most common combination therapy was endothelin receptor antagonist (ERA) plus phosphodiesterase-5 inhibitor (PDE5i), mostly macitentan plus sildenafil, for initial or sequential combination. The mean (SD) PDC was .71 (.33), and 1,117 (58.8%) patients were adherent. A significant difference in mean PDC was observed between initial ERA users and PDE5i users (p < .0001). No factor was significantly associated with medication adherence. Conclusion: Patients with PAH mostly initiated sildenafil as monotherapy, and macitentan was added as a sequential combination therapy. The initial ERA and combination groups showed higher medication adherence. Further investigations are needed to identify other factors associated with adherence.

Exploring the Agreement Between Self-Reported Medication Adherence and Pharmacy Refill-Based Measures in Patients with Kidney Disease

AIM

To assess the quantitative and categorical agreement between two methods of measuring medication adherence: pharmacy refill-based medication possession rates and self-reported medication adherence scale.

BACKGROUND

Categorisation of adherence metrics using empirical cut-off scores can lead to misclassification, which can be overcome by expressing adherence as a continuous variable. Pharmacy refill-based adherence can be reported as actual rates, but the validity of expressing self-reported medication adherence scores as a continuous variable to reflect adherence is unknown and its quantitative agreement with refill-based adherence rates untested.

METHODS

Patients with kidney disease, including dialysis patients, from Illawarra Shoalhaven region of New South Wales, Australia were recruited between January 2015 and June 2016 to this cross-sectional study. Medication adherence was assessed using the self-reported Morisky Medication Adherence Scale (MMAS) and two pharmacy refill-based measures, Medication Possession Ratio (MPR) and Proportion of Days Covered (PDC) for antihypertensives and cardiometabolic drugs. Categorical and quantitative agreement between self-reported adherence and pharmacy refill-based adherence were assessed using tests of trend, analysis of covariance (ANCOVA), Cohen's kappa and Bland-Altman analysis.

RESULTS

We recruited 113 patients. There was a significant declining trend of MPR (p < 0.001) and PDC (<0.001 for antihypertensives, p = 0.004 for cardiometabolic) scores among categories with worsening MMAS adherence. Adjusted ANCOVA showed significant association between self-report and pharmacy refill-based adherence (p < 0.001). Weighted Cohen's kappa statistics showed fair agreement between the self-report and pharmacy refill-based categories. Bland-Altman's analysis showed less than 5% of cases were outside the limits of agreement (-0.36 to 0.27) and the bias for MMAS was negative (-0.05 to -0.09), indicating MMAS did not overestimate adherence.

CONCLUSION

There is modest agreement between pharmacy refill-based measures and self-report MMAS measures when assessed categorically or quantitatively. Assessing adherence as a continuous variable should be considered to overcome the challenges associated with categorization of adherence based on arbitrary thresholds.

Longitudinal Oral Anticoagulant Adherence Trajectories in Patients With Atrial Fibrillation

BACKGROUND

Conventional adherence summary measures do not capture the dynamic nature of adherence.

OBJECTIVES

This study aims to characterize distinct long-term oral anticoagulant adherence trajectories and the factors associated with them in patients with atrial fibrillation.

METHODS

Adults with incident atrial fibrillation were identified using linked population-based administrative health data in British Columbia, Canada (1996-2019). Group-based trajectory modeling was used to model patients' 90-day proportions of days covered over time to identify distinct 5-year adherence trajectories. Multinomial regression analysis was used to assess the effect of various demographic and clinical factors on exhibiting each adherence trajectory.

RESULTS

The study cohort included 19,749 patients with AF (mean age: 70.6 ± 10.6 years), 56% male, mean CHA₂DS₂-VASc stroke risk score 2.8 ± 1.4. Group-based trajectory modeling identified 4 distinct oral anticoagulants adherence trajectories: "consistent adherence" (n = 14,631, 74% of the cohort), "rapid decline and discontinuation" (n = 2,327, 12%), "rapid decline and partial recovery" (n = 1,973, 10%), and "slow decline and discontinuation" (n = 819, 4%). Very few patient variables were found to be associated with specific adherence trajectories.

CONCLUSIONS

There is heterogeneity among nonadherent patients in the rate and timing of decline in their medication taking. Clinical and demographic characteristics were found to be inadequate to predict patients' adherence trajectories. Insights from this study could be used to inform the design and timing of adherence interventions, and qualitative studies may be needed to better understand the psychosocial determinants and reasons for the behaviors reflected in the identified trajectories.

Proportion of days covered as a measure of medication adherence

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Implicit and Explicit Attitudes Toward Antihypertensive Medications Explain Variation in Pharmacy Refill and Self-Reported Adherence Beyond Traditional Risk Factors: Potential Novel Mechanism Underlying Adherence

Background In pursuit of novel mechanisms underlying persistent low medication adherence rates, we assessed contributions of implicit and explicit attitudes, beyond traditional risk factors, in explaining variation in objective and subjective antihypertensive medication adherence. Methods and Results Implicit and explicit attitudes were assessed using the difference scores from the computer-based Single Category Implicit Association Test and the Necessity and Concerns subscales of the Beliefs about Medicines Questionnaire, respectively. Antihypertensive medication adherence was measured using pharmacy refill proportion of days covered (PDC: mean PDC, low PDC <0.8) and the self-report 4-item Krousel-Wood Medication Adherence Scale (K-Wood-MAS-4: mean K-Wood-MAS-4, low adherence via K-Wood-MAS-4 ≥1). Hierarchical logistic and linear regression models controlled for traditional risk factors including social determinants of health, explicit, and implicit attitudes in a stepwise fashion. Community-dwelling insured participants (n=85: 44.7% female; 20.0% Black; mean age, 62.3 years; 43.5% low PDC, and 31.8% low adherence via K-Wood-MAS-4) had mean (SD) explicit and implicit attitude scores of 7.188 (5.683) and 0.035 (0.334), respectively. Low PDC was inversely associated with more positive explicit (adjusted odds ratio [aOR], 0.87; 95% CI, 0.78-0.98; P=0.022) and implicit (aOR, 0.12; 95% CI, 0.02-0.80; P=0.029) attitudes, which accounted for an additional 8.6% (P=0.016) and 6.5% (P=0.029) of variation in low PDC, respectively. Lower mean K-Wood-MAS-4 scores (better adherence) were associated only with more positive explicit attitudes (adjusted β, -0.04; 95% CI, -0.07 to -0.01; P=0.026); explicit attitudes explained an additional 5.6% (P=0.023) of K-Wood-MAS-4 variance. Conclusions Implicit and explicit attitudes explained significantly more variation in medication adherence beyond traditional risk factors, including social determinants of health, and should be explored as potential mechanisms underlying adherence behavior.

Trends in coagulation factor replacement therapy and medical costs in patients with haemophilia in Taiwan: A population-based, 15-year analysis

INTRODUCTION

Taiwan's National Health Insurance Program approved reimbursement of prophylactic coagulation factor replacement therapy (CFRT) for patients with haemophilia (PWH) in 2014.

AIM

To examine 15-year trends and the impact of reimbursement for prophylactic CFRT on its utilization and related medical costs for PWH.

METHODS

We analysed Taiwan's National Health Insurance Database from 2003 to 2017. We included patients with haemophilia A (PWHA) or B (PWHB) receiving coagulating factor. Female patients were excluded because of small sample size. We analysed annual consumption of CFRT units and medical costs. High proportion of days covered (PDC) with CFRT served as an indicator for prophylactic treatment since it reflects routine use of CFRT. We applied interrupted time series analysis (ITSA) to evaluate the impact of reimbursement for prophylactic CFRT on usage patterns and medical costs.

RESULTS

We included 896 male PWHA and 181 male PWHB, with 38.1% and 37.0% aged under 18 years, respectively. By ITSA, we found the trends in coagulation factor consumption and PDC significantly increased after reimbursement for prophylactic CFRT in both PWHA and PWHB (p values for trend change <0.05). The overall medical costs per patient increased with increasing consumption of coagulation factor; however, ITSA revealed non-CFRT cost decreased after reimbursement of prophylactic CFRT for both PWHA and PWHB (p values <.05).

CONCLUSION

Reimbursement for prophylactic CFRT facilitated growth in rates of prophylactic CFRT and increased related costs, but curbed rising non-CFRT costs. These findings provide strong grounds for future cost-effectiveness studies to leverage prophylactic CFRT for its therapeutic benefits.

High level of medication adherence is required to lower mortality in patients with chronic hepatitis B taking entecavir: A nationwide cohort study

It is unclear whether suboptimal adherence contributes to adverse clinical outcomes in patients with chronic hepatitis B (CHB). Moreover, there is no consensus regarding the optimal level of drug adherence. This was a population-based historical cohort study including 51 975 adult CHB patients treated with entecavir (0.5 mg/d orally). Data were obtained from the Korean national health insurance service claims database, which covers >99% of the entire population, between 2007 and 2015. Medication adherence was categorized as high (proportion of days covered [PDC], ≥90%; n = 32 089), intermediate (PDC, 80%-89%; n = 10 197) and low (PDC, <80%; n = 9689). During a median 4.5 years (maximal 9 years) of follow-up in 51 975 CHB patients treated with entecavir, multivariable analyses revealed that the risk of mortality/transplantation was significantly greater in the low-adherers (adjusted hazard ratio [HR], 1.38; P < .001) and intermediate-adherers (adjusted HR, 1.44; P < .001) than the high-adherers (P for trend < 0.001). The risk of renal failure in the low- and intermediate-adherence groups was also significantly higher than the high-adherence group (P for trend < 0.001). By contrast, the risk of hepatocellular carcinoma (HCC) was not significantly different between groups (P for trend = 0.70). The higher risk of mortality/transplantation and renal failure but similar risk of HCC for low- and intermediate-adherers compared with high-adherers was consistent in inverse probability treatment weighting analysis of the entire cohort and subcohorts with or without cirrhosis. In conclusion, high medication adherence (≥90%) is required to significantly lower risk of mortality and renal failure in patients with CHB during long-term treatment with entecavir.

Comparing the Sensitivities of Measures of Adherence to Antihypertensive Drugs Using Korean National Health Insurance Claims Data

PURPOSE

Numerous studies have utilized various forms of adherence measures. However, methods for measuring adherence are inconsistent. Moreover, few studies are available that have compared sensitivities of the effects of several criteria on medication adherence. This study aims to compare measures of adherence using varied analytical decisions.

MATERIALS AND METHODS

We included three measures for adherence: proportion of days covered with one or more medications (PDC_with≥1), duration weighted mean PDC (PDC_wm), and daily polypharmacy possession ratio (DPPR). We compared the sensitivities of the measures by changing parameters in the Korean nationwide claims database. First, we used PDC_with≥1 as our base model. Then, we divided an adherence measure algorithm into three categories: (1) definition of data cleaning, (2) inclusion criteria and observation period, and (3) calculation methods of medication adherence. The categories included eight decision nodes that incorporated 25 alternative options. Finally, we assessed the medication adherence for the base-case with commonly used values and then varied to measure with each alternative option.

RESULTS

The base-case included 14,288 beneficiaries with antihypertensives. Among eight decisions, both handling an end-date-of-study and overlaps had the strongest impacts on measuring PDC_with≥1, PDC_wm, and DPPR, with small differences in sample size. Instead of the estimates of adherence from PDC_wm, those of PDC_with≥1 and DPPR were similar. Furthermore, a tendency toward a higher medication adherence was observed with a smaller study population.

CONCLUSION

The decisions regarding identifying an end-date-of-study and overlaps showed meaningful impacts of all three measures including PDC_with≥1, PDCwm, and DPPR on measuring medication adherence.

Low medication adherence is associated with decline in health-related quality of life: results of a longitudinal analysis among older women and men with hypertension

OBJECTIVE

The aim of this study was to determine the association of low antihypertensive medication adherence with decline in health-related quality of life (HRQOL) over 1 year.

METHODS

We used data from older men and women with hypertension (n = 1525) enrolled in the Cohort Study of Medication Adherence among Older Adults. Adherence was measured using the validated self-report four-item Krousel-Wood Medication Adherence Scale (K-Wood-MAS-4) (low adherence = score ≥1) and prescription refill-based proportion of days covered (PDC) (low adherence = PDC < 0.80). We defined decline in HRQOL as a decrease in Mental Component Summary (MCS) or Physical Component Summary (PCS) score (from the RAND 36-Item Health Survey 1.0 administered at two time points - at the time of adherence assessment and 1 year later) equivalent to the minimal important difference (MID) for each respective summary score, calculated as the average of MID estimates derived from distribution and anchor-based approaches.

RESULTS

The prevalence of low adherence was 38.6% using the K-Wood-MAS-4 and 23.9% using PDC. On the basis of mean MID estimates of 4.40 for MCS and 5.16 for PCS, 21.8 and 25.2% of participants experienced a decline in MCS and PCS, respectively, over 1 year. Low adherence was associated with a decline in MCS for K-Wood-MAS-4 [prevalence ratio = 1.32, 95% confidence interval (95% CI) 1.08-1.62, P = 0.008], but not PDC (prevalence ratio  = 1.17, 95% CI 0.94-1.47, P = 0.168). Low adherence was not associated with decline in PCS (K-Wood-MAS-4: prevalence ratio  = 0.95, 95% CI 0.79-1.16; PDC: prevalence ratio  = 1.10, 95% CI 0.90-1.35).

CONCLUSION

Low self-report medication adherence is associated with decline in mental HRQOL over 1 year in older adults with hypertension.

Statistical considerations for medication adherence research

OBJECTIVE

Medication non-adherence is a widespread problem and has been known to be associated with worse health outcomes and increased healthcare costs. Although many measures of adherence have been developed, their usage is not consistent across studies. Furthermore, statistical methods for analyzing adherence measures have not been rigorously evaluated.

METHODS

Using Proportion of Days Covered (PDC), a commonly used adherence measure, we examine the variability inherent to study inclusion criteria and several variations of the PDC calculation method using a motivating data example. We illustrated via sensitivity analyses the potential for flawed inference when modeling PDC as an outcome measure. We also performed simulation studies to investigate the statistical properties of three statistical models: logistic regression, negative binomial, and ordinal logistic regression models.

RESULTS

Our sensitivity analysis showed that parameter estimates can vary greatly depending on the rules for determining the study end date in calculating PDC, or the minimum number of fills in defining the cohort. In simulation studies, logistic regression had lower power than ordinal logistic and negative binomial regression models. Naivete to treatment was an important predictor of adherence and omitting it from statistical models can lead to inflated type I errors.

CONCLUSIONS

We discourage dichotomizing adherence data as it results in low power. The negative binomial model offers advantages in modeling adherence data, as it avoids the problematic use of a ratio in regression models. The ordinal logistic regression is robust to distributional assumptions with greater power, but naivete to treatment should be adjusted to reserve type I error rate. We also provide a recommendation for defining the observation window in calculating PDC.

Differential Patterns of Adherence to Opioid Therapy in Opioid Naïve and Opioid Existing Patients With Different Age Groups

Limited data are available on the adherence to opioid therapy and the influence of different patient groups on adherence. This study examined the patterns of adherence in opioid naïve and opioid existing patients with varying age and gender. This retrospective cohort study was conducted using the prescription databases in tertiary hospital settings in Malaysia from 2010 to 2016. Adult patients aged ≥18 years, receiving at least two opioid prescriptions, were included and stratified into the opioid naïve and existing patient groups. Adherence to opioid therapy was measured using the proportion of days covered (PDC), which was derived by dividing the total number of days covered with any opioids by the number of days in the follow-up period. Generalized linear modeling was used to assess factors associated with PDC. A total of 10,569 patients with 36,650 prescription episodes were included in the study. Of these, 91.7% (n = 9,696) were opioid naïve patients and 8.3% (n = 873) were opioid existing patients. The median PDC was 35.5% (interquartile range (IQR) 10.3–78.7%) and 26.8% (IQR 8.8–69.5%) for opioid naïve and opioid existing patients, respectively. A higher opioid daily dose (coefficient 0.010, confidence interval (CI) 0.009, 0.012 p < 0.0001) and increasing age (coefficient 0.002, CI 0.001, 0.003 p < 0.0001) were associated with higher levels of PDC, while lower PDC values were associated with male subjects (coefficient −0.0041, CI −0.072, −0.010 p = 0.009) and existing opioid patients (coefficient −0.134, CI −0.191, −0.077 p < 0.0001). The suboptimal adherence to opioid medications was commonly observed among patients with non-cancer pain, and the opioid existing patients were less adherent compared to opioid naïve patients. Increasing age and a higher daily opioid dose were factors associated with higher levels of adherence, while male and opioid existing patients were potential determinants for lower levels of adherence to opioid medications.

Adherence and Concomitant Medication Use among Patients on Warfarin Therapy: Insight from a Large Pharmacy Dispensing Database in Japan

Warfarin is a drug used for anticoagulation management, with a narrow therapeutic range and multiple drug-drug interactions. Adherence and proper use of concomitant medication are thus fundamental to the efficacy and safety of warfarin therapy. In 2012, we retrospectively analyzed data from three large-scale pharmacy chains in Japan. We included all adults (≥ 20 years old) with at least one record of warfarin dispensation. We examined patient demographic data, adherence as measured by medication possession ratio (MPR), and co-dispensation focusing on the number of concomitant dispensations and concurrent use of medications that increase bleeding risk. Thresholds of underadherence and overadherence were set at <0.9 and >1.1, considering the narrow therapeutic window. We reviewed 443007 warfarin dispensation records of 71340 individuals (median age, 73 years; 62% male). The MPR was 1.0 (interquartile range: 0.96-1.0), and underadherence and overadherence was found in 16.3 and 1.9% of individuals, respectively. The median number of co-dispensed drugs was eight at each pharmacy encounter, which did not differ by age group. Drugs associated with a high bleeding risk were dispensed in 40.0% of encounters and accounted for 16.4% of all co-dispensed drugs. In summary, we found optimal overall adherence, as assessed by MPR, among our Japanese study population, even when defining a strict cut-off value. However, polypharmacy was common in all age groups and medications with a high bleeding risk profile were often co-dispensed with warfarin. Future research addressing how these dispensation patterns affect patient outcome is warranted.

The association between pharmacy refill-adherence metrics and healthcare utilisation: a prospective cohort study of older hypertensive adults

AIMS

Methods that enable targeting and tailoring of adherence interventions may facilitate implementation in clinical settings. We aimed to determine whether community pharmacy refill-adherence metrics are useful to identify patients at higher risk of healthcare utilisation due to low antihypertensive adherence, who may benefit from an adherence intervention.

METHODS

We conducted a prospective cohort study, recruiting participants (n = 905) from 106 community pharmacies across the Republic of Ireland. Participants completed a structured interview at baseline and 12 months. Antihypertensive medication adherence was evaluated from linked pharmacy records using group-based trajectory modelling (GBTM) and proportion of days covered (PDC). Healthcare utilisation included self-reported number of hospital visits (emergency department visits and inpatient admissions) and general practitioner (GP) visits, over a 6-month period. Separate regression models were used to estimate the association between adherence and number of hospital/GP visits. The relative statistical fit of each model using different adherence metrics was determined using the Bayesian information criterion (BIC).

RESULTS

For the number of hospital visits, significant associations were observed only for PDC but not for GBTM. Each 10% increase in refill-adherence by PDC was significantly associated with a 16% lower rate of hospital visits (adjusted incidence rate ratio 0.84, 95% CI 0.72-0.98, P = 0.036). Poorer adherence using both measures was associated with higher GP visits. Improvements in BIC favoured models using PDC.

CONCLUSIONS

Medication refill-adherence, measured using PDC in community pharmacy settings, could be used to recognise poor antihypertensive adherence to enable effective targeting of clinical interventions to improve hypertension management and outcomes.

Methods for Measuring Multiple Medication Adherence: A Systematic Review-Report of the ISPOR Medication Adherence and Persistence Special Interest Group

BACKGROUND

A broad literature base exists for measuring medication adherence to monotherapeutic regimens, but publications are less extensive for measuring adherence to multiple medications.

OBJECTIVES

To identify and characterize the multiple medication adherence (MMA) methods used in the literature.

METHODS

A literature search was conducted using PubMed, PsycINFO, the International Pharmaceutical Abstracts, the Cumulative Index to Nursing and Allied Health Literature and the Cochrane Library databases on methods used to measure MMA published between January 1973 and May 2015. A two-step screening process was used; all abstracts were screened by pairs of researchers independently, followed by a full-text review identifying the method for calculating MMA. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to conduct this systematic review. For studies that met the eligibility criteria, general study and adherence-specific characteristics and the number and type of MMA measurement methods were summarized.

RESULTS

The 147 studies that were included originated from 32 countries, in 13 disease states. Of these studies, 26 used proportion of days covered, 23 used medication possession ratio, and 72 used self-reported questionnaires (e.g., the Morisky Scale) to assess MMA. About 50% of the studies included more than one method for measuring MMA, and different variations of medication possession ratio and proportion of days covered were used for measuring MMA.

CONCLUSIONS

There appears to be no standardized method to measure MMA. With an increasing prevalence of polypharmacy, more efforts should be directed toward constructing robust measures suitable to evaluate adherence to complex regimens. Future research to understand the validity and reliability of MMA measures and their effects on objective clinical outcomes is also needed.

Estimating Adherence Based on Prescription or Dispensation Information: Impact on Thresholds and Outcomes. A Real-World Study With Atrial Fibrillation Patients Treated With Oral Anticoagulants in Spain

Objective: To estimate drug exposure, Proportion of Days Covered (PDC) and percentage of patients with PDC ≥ 80% from a cohort of atrial fibrillation patients initiating oral anticoagulant (OAC) treatment. We employed three different approaches to estimate PDC, using either data from prescription and dispensing (PD cohort) or two common designs based on dispensing information only, requiring at least one (D1) or at least two (D2) refills for inclusion in the cohorts. Finally, we assessed the impact of adherence on health outcomes according to each method. Methods: Population-based retrospective cohort of all patients with Non Valvular Atrial Fibrillation (NVAF), who were newly prescribed acenocoumarol, apixaban, dabigatran or rivaroxaban from November 2011 to December 2015 in the region of Valencia (Spain). Patients were followed for 12 months to assess adherence using three different approaches (PD, D1 and D2 cohorts). To analyze the relationship between adherence (PDC ≥ 80) defined according to each method of calculation and health outcomes (death for any cause, stroke or bleeding) Cox regression models were used. For the identification of clinical events patients were followed from the end of the adherence assessment period to the end of the available follow-up period. Results: PD cohort included all patients with an OAC prescription (n = 38,802), D1 cohort excluded fully non-adherent patients (n = 265) and D2 cohort also excluded patients without two refills separated by 180 days (n = 2,614). PDC ≥ 80% ranged from 94% in the PD cohort to 75% in the D1 cohort. Drug exposure among adherent (PDC ≥ 80%) and non-adherent (PDC < 80%) patients was different between cohorts. In adjusted analysis, high adherence was associated with a reduced risk of death [Hazard Ratio (HR): from 0.82 to 0.86] and (except in the PD cohort) the risk for ischemic stroke (HR: from 0.61 to 0.64) without increasing the risk of bleeding. Conclusion: Common approaches to assess adherence using measures based on days' supply exclude groups of non-adherent patients and, also, misattribute periods of doctors' discontinuation to patient non-adherence, misestimating adherence overall. Physician-initiated discontinuation is a major contributor to reduced OAC exposure. When using the PDC80 threshold, very different groups of patients may be classified as adherent or non-adherent depending on the method used for the calculation of days' supply measures. High adherence and high exposure to OAC treatment in NVAF patients is associated with better health outcomes.

Impact of Appointment-Based Medication Synchronization on Proportion of Days Covered for Chronic Medications

Appointment-based medication synchronization (ABMS) programs have been associated with increased adherence and persistence to chronic medications. Adherence to statin therapy, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), and non-insulin antidiabetic medications (NIDM) are used to determine a health plan’s Centers for Medicare and Medicaid Services (CMS) Star Rating under a pay-for-performance model. The objective of this study was to evaluate the impact of implementing an ABMS program on overall pharmacy adherence measures for statins, ACEI/ARBs, and NIDM, as presented through the Electronic Quality Improvement Platform for Plans and Pharmacies (EQuIPP©) platform. This retrospective, pre-post ABMS program study evaluated EQuIPP© generated adherence performance measures, represented as proportion of days covered (PDC), 6-months before and 6- and 12-months after the ABMS service for statin therapy, ACEIs/ARBs, and NIDM. All adherence measures showed statistically significant improvement in PDC percentage post ABMS implementation, except for NIDM percentage in 6-months post-ABMS service. This study shows that a comprehensive medication synchronization program can enhance adherence measures that are important to health plans to increase CMS Star Rating under a pay-for-performance model.

Multifaceted interventions improve medication adherence and reduce acute hospitalization rates in medicaid patients prescribed asthma controllers

OBJECTIVE

To measure the effectiveness of managed care-led interventions in Medicaid subjects with asthma on medication adherence and acute hospitalization in Pennsylvania.

METHODS

A total of 3589 members (age range, 5-64 years) served by two Pennsylvania-based Medicaid managed care plans (southeastern Pennsylvania [SEPA] and Lehigh-Capital/New West Pennsylvania [LCNWPA]) with low adherence rates (proportion of days covered [PDC]; 20%-67%) for asthma controller prescription fills in 2012 were guided through a care continuum by a comprehensive asthma strategy, consisting of adherence-improvement interventions (grouped as general intervention [GI] or personalized intervention [PI] for higher-risk subjects). Medication adherence and acute hospitalization rates (emergency department [ED] and inpatient [IP]) were compared at baseline versus one-year post-intervention using paired t-test or signed-rank tests. Repeated measures analysis of variances detected the interaction effect of time by intervention group after controlling for sociodemographic covariates.

RESULTS

Member profiles in SEPA (n = 2 796) and LCNWPA (n = 793) were racially and ethnically distinct. Both cohorts experienced statistically significant improvements in mean PDC rate (+4.9% and +7.2%; p = 0.01 and p = 0.03, respectively), accompanied by significant reductions in ED visits (asthma-related: -23.0% and -17.5%, respectively; p < 0.01), and IP admissions (asthma-related: -37.1% and -40.0%, respectively; p < 0.01). The PI subcohorts showed significantly greater improvements in mean PDC versus GI subcohorts (p ≤ 0.04), whereas acute hospitalization rates were statistically comparable in the SEPA cohort, despite its greater asthma burden.

CONCLUSIONS

Managed care-led interventions can effectively improve medication adherence and reduce acute hospitalizations in high-risk Medicaid populations.

Analysis of a Community Pharmacy Intervention to Improve Low Adherence Rates to Oral Diabetes Medications

For patients with diabetes, suboptimal medication adherence contributes to disease progression, complications, and increased healthcare costs. Identification of, and intervention for patient-identified reasons for nonadherence are essential to improving medication adherence. This prospective, quality improvement study was conducted at an independent community pharmacy in the Mid-West United States. Patients with a proportion of days covered (PDC) for their oral antidiabetic medications of less than 80% were contacted by telephone and interviewed by a clinical pharmacist. The interviews and corresponding adherence interventions were guided by an abbreviated version of the Drug Adherence Work-Up (DRAW©) tool that focused on oral medications for diabetes. The change in PDC 120-days post-interview was assessed to determine the change in adherence rates. Patients receiving the pharmacist-delivered adherence intervention had significantly higher 120 day PDC values which are likely to indicate more regular medication-taking at home. Almost half of study patients signed up for medication synchronization and these patients trended toward higher PDC values, although the relative difference was not statistically significant from those receiving the intervention and not opting to have their medications synchronized.

Impact of hospitalization on medication adherence estimation in claims data

WHAT IS KNOWN AND OBJECTIVE

Pharmacy claims are commonly used to assess medication adherence. It is unclear how different approaches to handling hospitalizations compare to the gold standard of using outpatient and inpatient drug data. This study aimed to compare the impact of different approaches to handling hospitalizations on medication adherence estimation in administrative claims data.

METHODS

We identified β-blocker initiators after myocardial infarction (MI) and statin initiators regardless of hospitalization histories in the population-based, Taiwan database, which includes outpatient and inpatient drug claims data. Adherence to β-blockers or to statins during a 365-day follow-up period was estimated in outpatient pharmacy claims using the proportion of days covered (PDC) in three ways: ignoring hospitalizations (PDC1); subtracting hospitalized days from the denominator (PDC2); and assuming drug use on all hospitalized days (PDC3). We compared these to an approach that incorporated inpatient drug use (PDC4). We also used a hypothetical example to examine variations across approaches in several scenarios, such as increasing hospitalized days.

RESULTS AND DISCUSSION

Mean 365-day PDC was 74% among 1729 post-MI β-blocker initiators (range: 73.1%-74.9%) and 44% among 69 435 statins initiators (range: 43.5%-44.0%), which varied little across approaches. Differences across approaches increased with increasing number of hospitalized days. For patients hospitalized for >28 days, mean difference across approaches was >15%. PDC3 consistently yielded the highest value and PDC1 the lowest.

WHAT IS NEW AND CONCLUSIONS

On average, different approaches to handling hospitalizations lead to similar adherence estimates to the gold standard of incorporating inpatient drug use. When patients have many hospitalization days during follow-up, the choice of approach should be tailored to the specific setting.

Associations between adherence and outcomes among older, type 2 diabetes patients: evidence from a Medicare Supplemental database

OBJECTIVE

To examine the association between adherence to glucose-lowering agents and patient outcomes, including costs, acute-care resource utilization, and complications, in an older, type 2 diabetic population.

DATA AND METHODS

The study used Truven's Medicare Supplemental database from July 1, 2009 to June 30, 2014. Patients aged 65 years or older were included if they had at least two type 2 diabetes diagnoses and received a glucose-lowering agent from July 1, 2010 through June 30, 2011. Multivariable analyses examined the relationships among 3-year patient outcomes and levels of adherence, proxied by the proportion of days covered. Outcomes included all-cause medical costs, diabetes-related medical costs, acute-care resource utilization, and acute complications.

RESULTS

In this study (N=123,235), higher adherence was linked to reduced costs and improved health outcomes. For example, comparing an individual with adherence of proportion of days covered <20% to one with proportion of days covered ≥80% illustrates an average saving of $28,824 in total 3-year costs. Furthermore, a 1% increase in adherence among 1,000 patients was associated with all-cause savings of $65,464 over 3 years. The probability of a hospitalization, an emergency room (ER) visit, or an acute complication decreased monotonically as adherence levels got higher, as did the number of hospitalizations, ER visits, and days hospitalized (P<0.005).

CONCLUSION

Higher adherence was associated with substantially less need for acute care, as indicated by a lowered probability of hospitalization or ER use, a reduced risk of an acute complication, and a decreased number of hospitalizations, ER visits, and days hospitalized. Higher adherence was also generally associated with lower all-cause and diabetes-related total costs, despite higher drug costs. These lower total costs were driven by the diminished acute care and outpatient costs. Results suggest that higher glucose-lowering agent adherence is associated with significant benefits for payers and older patients with type 2 diabetes.

Factors associated with adherence to oral antihyperglycemic monotherapy in patients with type 2 diabetes

AIM

To estimate the rate of adherence to oral antihyperglycemic monotherapy for patients with type 2 diabetes in the US and describe factors associated with adherence in these patients.

MATERIALS AND METHODS

In this retrospective cohort analysis, patients aged 18 years or older with a type 2 diabetes diagnosis received between 1 January 2007 and 31 March 2010 were identified using a large US-based health care claims database. The index date was defined as the date of the first prescription for oral antihyperglycemic monotherapy during this period. Patients had to have continuous enrollment in the claims database for 12 months before and after the index date. Adherence was assessed using proportion of days covered (PDC) and an adjusted logistic regression analysis was performed to evaluate factors associated with adherence (PDC ≥80%).

RESULTS

Of the 133,449 eligible patients, the mean age was 61 years and 51% were men. Mean PDC was 75% and the proportion of patients adherent to oral antihyperglycemic monotherapy was 59%. Both mean PDC and PDC ≥80% increased with increasing age and the number of concomitant medications, and were slightly higher in men compared to women. Results from the logistic regression demonstrate an increased likelihood of non-adherence for patients who were younger, new to therapy, on a twice-daily dose, female, or on fewer than three concomitant medications compared to their reference groups. Higher average daily out-of-pocket pharmacy expense was also associated with an increased likelihood of non-adherence. All results were statistically significant (P<0.05).

CONCLUSION

Patient characteristics, treatment regimens, and out-of-pocket expenses were associated with adherence to oral antihyperglycemic monotherapy in our study.

Drug adherence to olmesartan/amlodipine fixed combination in an Italian clinical practice setting

Objective

To investigate the criteria for prescribing a combination pill for hypertensive patients, and whether the combination pill improves medication adherence.

Materials and methods

This was a retrospective cohort study, performed in three Italian local health units. We selected all adult subjects who received at least one prescription of antihypertensive drugs between September 1, 2011 and December 31, 2011 (the enrollment period). The date of the first antihypertensive claim was defined as the index date. For each patient, we documented the antihypertensive drug treatments and evaluated patients’ adherence to treatment, which was calculated, separately, as the proportion of days covered in the two 6-month periods preceding and following the index date. Only patients treated with olmesartan and/or amlodipine as a single therapy, or as a two-pill combination in the period prior the index date were included. Changes in adherence levels were compared in subjects who moved to the fixed combination of olmesartan/amlodipine after the index date and in subjects who did not.

Results

A cohort of 21,008 subjects with a 6-month history of a prescription of olmesartan and amlodipine as two pills in a combination treatment, or as single-pill treatment, was obtained. Subjects treated with the two-pill combination treatment moved to the olmesartan/amlodipine fixed combination treatment more frequently than did subjects with a single-pill treatment (P<0.001). Comparing the postindex date period to the preindex date period, adherence to treatment was found to be higher in the 239 subjects who moved to the olmesartan/amlodipine fixed combination therapy (from 59.0% to 78.7%; P<0.001), than in the 20,769 subjects who did not move to the olmesartan/amlodipine fixed combination therapy (from 56.3% to 63.0%, P<0.001).

Conclusion

The results of the present study show that the fixed combination of olmesartan/amlodipine contributes to increasing treatment adherence in subjects previously treated with a two-pill combination therapy or a single-pill therapy.