Antiparkinson drug adherence and its association with health care utilization and economic outcomes in a Medicare Part D population

Adherence to istradefylline in patients with Parkinson's disease: A group-based trajectory analysis

BACKGROUND

Understanding the different patterns of adherence to istradefylline treatment is essential to identifying Parkinson's disease (PD) patients who might benefit from targeted interventions.

OBJECTIVES

This descriptive study aimed to identify longitudinal istradefylline adherence patterns and to characterize factors associated with them.

METHODS

We identified PD patients aged 21-99 years who initiated istradefylline treatment in a Japanese hospital administrative database. Group-based trajectory modeling was used to model the monthly proportion of days covered over time to identify distinct 360-day adherence patterns. Factors associated with each adherence pattern were assessed using univariable multinomial logistic regression models.

RESULTS

Of 2088 eligible PD patients, 4 distinct adherence groups were identified: consistently high adherence (56.8%); rapidly declining adherence (25.8%); gradually declining adherence (8.5%); and gradually declining and then recovering adherence (9.0%). Compared to the consistently high adherence group, the other groups had the following characteristics associated with a likelihood of lower adherence: the rapidly declining adherence group received fewer dopamine agonists (63.8% vs. 69.4%), monoamine oxidase B (MAO-B) inhibitors (26.8% vs. 31.6%), and catechol-O-methyl transferase inhibitors (31.6% vs. 37.0%) and had a higher prevalence of anxiety/mood disorders (29.9% vs. 24.6%); the gradually declining adherence group received fewer MAO-B inhibitors (22.5% vs. 31.6%) and amantadine (8.4% vs. 16.1%) and had a higher prevalence of mild cognitive impairment/dementia (27.0% vs. 18.8%); and the declining and then recovering adherence group had a higher prevalence of anxiety/mood disorders (34.2% vs. 24.6%).

CONCLUSIONS

Clinicians should be aware of the heterogeneous patterns of adherence to istradefylline.

Medication adherence and costs of medical care among patients with Parkinson's disease: an observational study using electronic medical records

BACKGROUND

Adherence to antiparkinsonian drugs (APDs) is critical for patients with Parkinson's disease (PD), for which medication is the main therapeutic strategy. Previous studies have focused on specific disorders in a single system when assessing clinical factors affecting adherence to PD treatment, and no international comparative data are available on the medical costs for Chinese patients with PD. The present study aimed to evaluate medication adherence and its associated factors among Chinese patients with PD using a systematic approach and to explore the impact of adequate medication adherence on direct medical costs.

METHODS

A retrospective analysis was conducted using the electronic medical records of patients with PD from a medical center in China. Patients with a minimum of two APD prescriptions from January 1, 2016 to August 15, 2018 were included. Medication possession ratio (MPR) and proportion of days covered were used to measure APD adherence. Multiple linear regression analysis was used to identify factors affecting APD adherence. Gamma regression analysis was used to explore the impact of APD adherence on direct medical costs.

RESULTS

In total, 1,712 patients were included in the study, and the mean MPR was 0.68 (± 0.25). Increased number of APDs and all medications, and higher daily levodopa-equivalent doses resulted in higher MPR (mean difference [MD] = 0.04 [0.03-0.05]; MD = 0.02 [0.01-0.03]; MD = 0.03 [0.01-0.04], respectively); combined digestive system diseases, epilepsy, or older age resulted in lower MPR (MD = -0.06 [-0.09 to -0.03]; MD = -0.07 [-0.14 to -0.01]; MD = -0.02 [-0.03 to -0.01], respectively). Higher APD adherence resulted in higher direct medical costs, including APD and other outpatient costs. For a 0.3 increase in MPR, the two costs increased by $34.42 ($25.43-$43.41) and $14.63 ($4.86-$24.39) per year, respectively.

CONCLUSIONS

APD adherence rate among Chinese patients with PD was moderate and related primarily to age, comorbidities, and healthcare costs. The factors should be considered when prescribing APDs.

The impact of China's zero markup drug policy on drug costs for managing Parkinson's disease and its complications: an interrupted time series analysis

Background

In April 2009, the Chinese government launched Zero Markup Drug Policy (ZMDP) to adjust medical institutions' revenue and expenditure structures.

Objective

This study evaluated the impact of implementing ZMDP (as an intervention) on the drug costs for managing Parkinson's disease (PD) and its complications from the healthcare providers' perspective.

Methods

The drug costs for managing PD and its complications per outpatient visit or inpatient stay were estimated using electronic health data from a tertiary hospital in China from January 2016 to August 2018. An interrupted time series analysis was conducted to evaluate the immediate change following the intervention (step change, β₁) and the change in slope, comparing post-intervention with the pre-intervention period (trend change, β₂). Subgroup analyses were conducted in outpatients within the strata of age, patients with or without health insurance, and whether drugs were listed in the national Essential Medicine List (EML).

Results

Overall, 18,158 outpatient visits and 366 inpatient stays were included. Outpatient (β₁ = -201.7, 95%CI: -285.4, -117.9) and inpatient (β₁ = -372.1, 95% CI: -643.6, -100.6) drug costs for managing PD significantly decreased when implementing ZMDP. However, for outpatients without health insurance, the trend change in drug costs for managing PD (β₂ = 16.8, 95% CI: 8.0, 25.6) or PD complications (β₂ = 12.6, 95% CI: 5.5, 19.7) significantly increased. Trend changes in outpatient drug costs for managing PD differed when stratifying drugs listed in EML (β₂ = -1.4, 95% CI: -2.6, -0.2) or not (β₂ = 6.3, 95%CI: 2.0, 10.7). Trend changes of outpatient drug costs for managing PD complications significantly increased in drugs listed in EML (β₂ = 14.7, 95% CI 9.2, 20.3), patients without health insurance (β₂ = 12.6, 95% CI 5.5, 19.7), and age under 65 (β₂ = 24.3, 95% CI 17.3, 31.4).

Conclusions

Drug costs for managing PD and its complications significantly decreased when implementing ZMDP. However, the trend in drug costs increased significantly in several subgroups, which may offset the decrease at the implementation.

The economic burden of Parkinson disease among Medicare beneficiaries

BACKGROUND: The progressive nature of Parkinson disease (PD), together with a lack of curative treatments, contributes to its economic burden. OBJECTIVE: To estimate the longitudinal incremental costs attributable to PD among Medicare beneficiaries. METHODS: In this retrospective cohort study, we used data from the Chronic Conditions Data Warehouse to identify Medicare beneficiaries with and without PD-related claims identified from 2006 to 2014 with follow-up until 2015. We grouped PD cases and controls based on their survival profiles using a grouping algorithm that used the following baseline measures: age, race, sex, and comorbidity. We identified 3 survival groups and used them to stratify the descriptive annual cost estimates in the 9 years after the index date. We estimated the incremental 1-, 3-, and 5-year costs of PD using generalized linear models (GLM) that controlled for baseline factors. RESULTS: We identified 27,394 cases and controls who were grouped into 3 survival groups. The mean age of the full study sample was 73 years. No material differences were found in the incremental cost of PD across the survival groups. Based on the multivariable GLM, the 1-year incremental cost of PD was $9,625 (95% CI, $9,054-$10,197). The 3-year incremental cost of PD was $20,832 (95% CI, $19,390-$22,274). The 5-year incremental cost of PD was $27,466 (95% CI, 25,088-$29,844). CONCLUSIONS: Among Medicare beneficiaries, PD is associated with excess costs compared with controls. We did not identify substantial differences in the incremental cost of PD across the survival groups. DISCLOSURES:This study was funded by Pfizer Inc. The funding agreement did not impact the authors' independence in designing the study, collecting the data, interpreting the data, writing the manuscript, and submitting the manuscript for publication. Dr Onukwugha reports grants from Pfizer Inc for the conduct of this study and is an employee of University of Maryland, Baltimore, which received financial support from Pfizer Inc in connection with the development of this manuscript; Dr Shulman reports research funding from Pfizer Inc related to the current work, is an employee of University of Maryland, Baltimore, which received financial support from Pfizer Inc in connection with the development of this manuscript, and reports research funding from the NIH, The Rosalyn Newman Foundation, and the Eugenia and Michael Brin family unrelated to the current work and royalties from Oxford University Press and Johns Hopkins University Press; Ms Myers and Dr Alvir are employees and stockholders of Pfizer Inc; Dr Gray was an employee and stockholder of Pfizer Inc at the time of analysis.

Impact of a Collaborative Pharmaceutical Care Service for Patients With Parkinson's Disease

Objective: To identify the impact of a collaborative pharmaceutical care service (CPCS) on medication safety and establish the impact of the CPCS on patient reported outcomes for Parkinson's disease (PD) patients. Methods: Initially, PD outpatients receiving the CPCS between March 2017 and March 2019 were compared with PD patients receiving standard of care to identify differences in management. Pharmacist interventions data were coded and patients with PD receiving the CPCS were compared with those receiving standard of care to determine differences in medicines prescribed and dosage associated with these. Following this, data of patients receiving CPCS at baseline and 3-months follow-up were collected using a questionnaire consisting of validated measures of two patient-reported outcomes [adherence and quality of life (QoL)]. Mean scores for continuous variables were calculated, with descriptive analysis of categorical variables consisting of frequency counts and percentages. Change in adherence score before and after CPCS was investigated using a Wilcoxon sign rank sum test, spearman correlation analysis was used to correlate the changes in QoL before and after CPCS with the number of interventions, and p < 0.05 indicates that the difference is statistically significant. Results: A total of 331 PD outpatients received CPCS over 490 outpatient visits with an average age of 71.83 (±12.54). Five hundred and forty-five drug related problems were recorded as pharmacist interventions, of which most involved change to dosage (n = 226, 41.47%), adverse drug reactions (n = 135, 24.77%), and change in a medication (n = 102, 18.72%). Compared with those receiving standard of care, patients receiving CPCS were significantly less likely to have been prescribed pramipexole (18.52 versus 23.77%, p < 0.001) and more likely to have been prescribed amantadine (5.40 versus 3.70%, p = 0.02) and selegiline (17.36 versus 11.64%, p < 0.001). Lower dosages of levodopa/benserazide (0.51 ± 0.31 g versus 0.84 ± 0.37 g, p < 0.001), levodopa/carbidopa (0.33 ± 0.23 g versus 0.66 ± 0.47 g, p < 0.001), pramipexole (1.14 ± 1.63 mg versus 1.27 ± 0.69 mg, p = 0.01), and entacapone (130.00 ± 79.76 mg versus 173.09 ± 97.86 mg, p < 0.001) were also recorded. At baseline 119 PD outpatients with an average age of 69.98 (±9.90) were recruited for the longitudinal study. At 3-month follow-up, participants reported improvement in bodily pain subscale (baseline versus 3-months follow-up, 30.04 ± 22.21 versus 23.01 ± 20.98, p = 0.037) and medication adherence (6.19 ± 1.50 versus 6.72 ± 1.73, p = 0.014). Frequency of CPCS use was related to activity of daily living subscale (p = 0.047), the bodily pain subscale (p = 0.026), and medication adherence (p = 0.011). Total score of PDQ-39 was associated with patient education (p = 0.005) and usage and dosage combined with patient education (p = 0.006), while medication adherence score was associated with usage and dosage (p = 0.005). Conclusion: The CPCS was effective in resolving drug-related problems and in improving patients' medication regimens, medication adherence, and QoL through patient education and dosage adjustments. This is the first step in the development and feasibility testing of pharmacy services for PD patients in China.

Adherence to treatment in Parkinson's disease: A multicenter exploratory study with patients from six Latin American countries

BACKGROUND

Adherence to treatment in Parkinson's disease (PD) is compromised due to the need for multiple therapies, comorbidities related to aging, and the complexity of therapeutic schemes. In the present study, we aimed to explore adherence to treatment in groups of PD patients from six Latin-American (LA) countries and identify its associated demographic and clinical parameters.

METHODS

A multicenter, cross-sectional, exploratory study was conducted from September 2016 to March 2017. Treatment adherence was assessed using the simplified medication adherence questionnaire (SMAQ), applied to patients and caregivers. Sociodemographic and clinical variables (MDS-UPDRS Part III-IV, MMSE, Beck Depression Inventory-II (BDI-II)) were recorded.

RESULTS

Eight hundred patients from six LA countries were evaluated. Nonadherence was reported in 58.25% of the population, according to patients. The most frequent issues were forgetfulness and correct timing of doses. A high level of agreement in adherence prevalence and most SMAQ items were observed between patients and their caregivers. The nonadherent population had a significantly higher proportion of unemployment, free access to medication, troublesome dyskinesias and off-periods, lesser years of education, and worse motor, cognitive, and mood scores. In multiple logistic and linear regression analyses, MDS-UPDRS Part III, BDI-II, gender, free access to medication, treatment with dopamine agonists alone, years of education, excessive concerns about adverse effects, and beliefs about being well-treated remained significant contributors to adherence measures.

CONCLUSION

Educational strategies, greater involvement of PD patients in decision-making, and consideration of their beliefs and values might be of great need to improve medication adherence in this PD population.

Health Care Resource Utilization Associated With Parkinson Disease Among Medicare Beneficiaries

OBJECTIVE

To compare differences in health care resource utilization (HcRU) over time between Medicare beneficiaries with and without Parkinson disease (PD).

METHODS

This retrospective observational study used the Chronic Conditions Data Warehouse (5% Medicare sample) between 2005 and 2015. In a propensity score-matched (age, sex, race, and comorbidity adjusted) sample of beneficiaries with and without PD, we examined all-cause HcRU due to inpatient admissions, emergency department (ED) admissions, skilled nursing facility (SNF) admissions, health care provider encounters, neurologist visits, rehabilitation service visits, and non-PD medication fills. Relative to beneficiaries without PD, we reported adjusted incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for beneficiaries with PD using generalized linear models with log link and negative binomial variance functions.

RESULTS

A total of 467,064 Medicare enrollees (unmatched sample) met the inclusion criteria. Of these, 3.3% had PD. In the matched sample and relative to beneficiaries without PD, beneficiaries with PD displayed higher rates of inpatient admissions (IRR 1.29, 95% CI 1.24-1.34), ED admissions (IRR 1.31, 95% CI 1.27-1.34), SNF admissions (IRR 2.00, 95% CI 1.92-2.09), health care provider encounters (IRR 1.18, 95% CI 1.16-1.20), neurologist visits (IRR 5.57, 95% CI 5.35-5.78), rehabilitation service visits (IRR 1.47, 95% CI 1.41-1.53), and non-PD medication fills (IRR 1.10, 95% CI 1.08-1.11) over time.

CONCLUSION

These results reflect patterns of medical care among Medicare beneficiaries with PD. The findings can help clinicians, payers, and policy makers make evidence-based decisions for the allocation of scarce health care resources for PD management.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that Medicare beneficiaries with PD use more health care resources than matched controls without PD.

Reasons for hospitalization and factors of mortality in patients with Parkinson's disease in the Philippines

Aim: We aimed to determine the reasons for hospitalizations and factors of mortality of Filipino Parkinson's disease (PD) patients in a tertiary hospital. Methods: We conducted a retrospective review of medical records of PD patients admitted to our institution between 2016 and 2018. Demographic and clinical data were analyzed. Results: We included 166 PD patients. The most common cause of admission was infectious (pneumonia, urinary tract, and skin-soft tissue infections) (n = 65, 39.2%). The most common cause of mortality was sepsis (n = 9, 5.4%). Renal comorbidity was a significant factor of mortality (OR: 3.67, 95% CI: 1.11-12.12; p = 0.033). Conclusion: Interventions designed to reduce the risk of complications in PD patients should be prioritized to potentially decrease the probability of eventual hospitalization.

Low Sustainment of High-Dose Oral Medication Regimens for Advanced Parkinson's Disease in Medicare Beneficiaries

BACKGROUND

Increasing doses of oral antiparkinson medications are indicated in advanced Parkinson's disease (PD), but little is known about sustainment of high-dose regimens.

OBJECTIVE

To investigate sustainment of high-dose oral medication regimens in Medicare beneficiaries with incident advanced PD.

METHODS

This retrospective cohort study utilized 100%fee-for-service Medicare claims from 2011-2013. We identified advanced PD using a pharmacy claims-based proxy and selected patients who initiated a new high-dose oral medication regimen (daily levodopa equivalent dose [LED] >1000 mg/day for ≥30 days) in 2012. In the following 12 months, we examined: 1) annual proportion of days covered (PDC)≥0.80 and 2) presence of a ≥ 90 day continuous gap at varying dosage thresholds: the initial >1000 mg/day, >800 mg/day, >500 mg/day, or >0 mg/day.

RESULTS

We identified 9,405 patients with advanced PD (mean age 77.4 [SD 6.8] years; 53%men). Only 5%maintained a regimen of >1000 mg/day at PDC ≥0.80; 75% had a ≥ 90-day gap in that dosage level. At a dosage threshold of >800 mg/day, 20% had a PDC ≥0.80 and 53% had a ≥ 90-day gap; at >500 mg/day, 56% had a PDC ≥0.80 and 19%had a ≥ 90-day gap; and at >0 mg/day (any dose), 76% had a PDC ≥0.80 and only 10%had a≥90-day gap.

CONCLUSION

Few patients with advanced PD sustained a high-dose oral medication regimen in the year following initiation, but most sustained a substantially lower-dose regimen. Strategies to improve advanced PD treatment are needed.

The economic benefit of timely, adequate, and adherence to Parkinson's disease treatment: the Value of Treatment Project 2

BACKGROUND

Parkinson's disease (PD) is a chronic progressive neurological disorder with a high psychosocial and economic burden. As part of the European Brain Council (EBC)-led Value of Treatment project, this study aimed to capture the economic benefit of timely, adequate, and adherence to PD treatment.

METHODS

The EBC Value of Treatment Initiative combined different stakeholders to identify unmet needs in the patients' journey according to Rotterdam methodology. The economic evaluation focused on three major topics identified as major gaps: start of treatment; best treatment for advanced disease; and adherence to treatment. Two separate healthcare systems (Germany and the UK) were chosen. Cost-effectiveness was determined by using decision-analytical modelling approaches. Effectiveness was expressed as quality-adjusted life-years (QALYs) gained and incremental cost-effectiveness ratio (ICER).

RESULTS

Treatment intervention in PD was found to be cost-effective regardless of the initial health state of the patient receiving the treatment. Cost savings were between -€1000 and -€5400 with 0.10 QALY gain and -€1800 and -€7600 with 0.10 QALY gain for Germany and the UK, respectively. Treatment remains cost-effective within the National Institute for Health and Care Excellence thresholds. Availability of adequate treatment to more patients was also found to be cost-effective, with an ICER of €15,000-€32,600 across country settings. Achieving the target adherence to treatment would generate cost-savings of €239,000-€576,000 (Germany) and €917,000-€2,980.000 (UK) for every 1,000 patients treated adequately.

CONCLUSIONS

The analyses confirmed that timely, adequate, and adherence to PD treatment will not only improve care of the patients but is also cost-effective across healthcare systems. Further studies with a distinct identification of gaps in care are necessary to develop better and affordable care.

Burden of Parkinson's Disease by Severity: Health Care Costs in the U.S. Medicare Population

BACKGROUND

Current understanding of the health care costs of Parkinson's disease (PD) and the incremental burden of advanced disease is incomplete.

OBJECTIVES

The aim of this study was to assess the direct economic burden associated with advanced versus mild/moderate PD in a prevalent national sample of elderly U.S. Medicare beneficiaries with a PD diagnosis.

METHODS

Analyzing 100% fee-for-service Medicare claims from 2013, we defined advanced PD with a medication-based algorithm and calculated all-cause and PD-related costs for the overall sample and by disease severity. We measured primary PD-related costs (based on claims with a primary diagnosis of PD) and any PD-related costs (based on claims with PD in any diagnostic field). Generalized linear models were used to estimate risk-adjusted mean cost differences between the advanced and mild/moderate PD groups for the calendar year.

RESULTS

The final sample (N = 144,703) had mean observed all-cause, primary PD-related, and any PD-related costs of $23,041 (SD, $34,045), $3429 (SD, $7431), and $9924 (SD, $22,140), respectively. Twenty percent of patients were classified as advanced PD. Costs varied substantially; any PD-related mean costs were $483 for the lowest patient decile (which included 1% of the advanced group) and $48,145 for the highest decile (which included 15% of the advanced group). Incremental risk-adjusted costs of advanced PD were $5818 (95% confidence interval [CI]: $5411-$6225) for all-cause costs, $3644 (95% CI: $3484-$3806) for primary PD-related costs, and $6088 (95% CI: $5779-$6398) for any PD-related costs.

CONCLUSIONS

Elderly Medicare beneficiaries with PD had substantial variation in PD-related costs. Advanced PD was associated with a larger economic burden than mild/moderate PD. © 2020 International Parkinson and Movement Disorder Society.

Adherence to Pharmacotherapy in Patients With Parkinson's Disease Taking Three and More Daily Doses of Medication

Background: Once-daily treatment formulation is associated with better adherence in comparison to more complex medication regimens. The study aimed to detect the extent of adherence to pharmacotherapy in Parkinson disease (PD) patients who take a minimum of three daily doses of drugs, and to identify factors associated with lower levels of adherence.

Methods: The cohort was selected from non-demented PD patients. The 8-Item Morisky Medication Adherence Scale (MMAS-8), 8-Item Parkinson's Disease Questionnaire (PDQ-8), Geriatric Depression Scale (GDS), Non-Motor Symptom Assessment Scale (NMSS), 9-Item Wearing-off Questionnaire (WOQ-9), MDS-UPDRS III (motor examination), and IV (motor complications) scales were used in this study.

Results: From a total of 124 subjects, 33.9% reported a high level of adherence, 29.8% reported a medium level of adherence, and 36.3% reported a low level of adherence to their pharmacotherapy. The level of non-adherence correlated with gender, longer disease duration, higher scores of PDQ-8, NMSS, WOQ-9, and MDS-UPDRS IV. Detailed analysis of NMSS demonstrated a correlation between the level of adherence and domains sleep/fatigue, mood/cognition, perceptual problems/hallucinations, attention/memory, and urinary symptoms. Independent risk factors for non-adherence were excessive daytime sleepiness, anhedonia, and forgetfulness.

Conclusion: Non-adherence to more complicated medication regimens is frequent in PD patients and is associated with gender, longer PD duration, poorer quality of life, frequency and severity of non-motor symptoms, and more severe motor and non-motor fluctuations. Non-adherence was predicted by non-motor symptoms including fatigue, mood disturbances, and subjective cognitive complaints.

Clinical aspects of adherence to pharmacotherapy in Parkinson disease: A PRISMA-compliant systematic review

BACKGROUND

Parkinson disease (PD) is the second most common neurodegenerative disease with various motor and nonmotor symptoms. Progressive course of PD requires frequent medication adjustments. Various combinations of drugs and dose regimens could be used to control symptoms. Thus, not surprisingly, adherence to pharmacotherapy is frequently suboptimal in these patients having negative effect on motor control and patient's quality of life.

METHODS

In this article, we offer up-to-date review of adherence in PD compared with other chronic conditions. In addition, we summarize factors influencing level of adherence, ways of measuring, and methods of adherence optimization. For the review of adherence in PD, a literature search was undertaken using PubMed database and relevant search terms. Articles were screened for suitability and data relevance.

RESULTS

PubMed and Scopus databases were systematically searched in 2016 and data extraction was a multistep process based on the PRISMA Guidelines.

CONCLUSION

According to the recent data, sufficient control of motor symptoms and adequate quality of life are primary goals in the treatment of PD. Adherence to pharmacotherapy play a key role in this process, thus the medication should be tailored for each patient. In order to improve level of suboptimal adherence, these patients should have got recommended various dosing devices or alarms. Good communication with the patients and their relatives or caregivers is also essential.

The association of antidepressant treatment with COPD maintenance medication use and adherence in a comorbid Medicare population: A longitudinal cohort study

The effect of treating comorbid depression to achieve optimal management of chronic obstructive pulmonary disease (COPD) has not yet empirically tested. We examined the association between antidepressant treatment and use of and adherence to COPD maintenance medications among patients with new-onset COPD and comorbid depression.

METHODS

Using 2006-2012 Medicare data, this retrospective cohort study identified patients with newly diagnosed COPD and new-onset major depression. Two exposures-antidepressant use (versus non-use) and adherence measured by proportion of days covered (PDC) (PDC ≥0.8 versus <0.8)-were assessed quarterly. We used marginal structural models to estimate the effects of prior antidepressant use and adherence on subsequent COPD maintenance inhaler use and adherence outcomes, accounting for time-varying confounders.

RESULTS

A total of 25 458 COPD-depression patients, 82% with antidepressant treatment, were followed for a median of 2.5 years. Nearly half (48%) used at least 1 COPD maintenance inhaler in any given quarter; among users, 3 in 5 (61%) had a PDC of <0.8. Compared to patients with no antidepressant treatment, those with antidepressant use were more likely to use (relative ratio [RR] = 1.15, 95% confidence interval [CI] = 1.12- 1.17) and adhere to (RR = 1.08, 95% = 1.03-1.14) their COPD maintenance inhalers. Patients who adhered to antidepressant treatment were more likely to use and adhere to COPD maintenance inhalers.

CONCLUSION

Regularly treated depression may increase use of and adherence to necessary maintenance medications for COPD. Antidepressant treatment may be a key determinant to improving medication-taking behaviors among COPD patients comorbid with depression.

Economic impact of medication non-adherence by disease groups: a systematic review

OBJECTIVE

To determine the economic impact of medication non-adherence across multiple disease groups.

DESIGN

Systematic review.

EVIDENCE REVIEW

A comprehensive literature search was conducted in PubMed and Scopus in September 2017. Studies quantifying the cost of medication non-adherence in relation to economic impact were included. Relevant information was extracted and quality assessed using the Drummond checklist.

RESULTS

Seventy-nine individual studies assessing the cost of medication non-adherence across 14 disease groups were included. Wide-scoping cost variations were reported, with lower levels of adherence generally associated with higher total costs. The annual adjusted disease-specific economic cost of non-adherence per person ranged from $949 to $44 190 (in 2015 US$). Costs attributed to 'all causes' non-adherence ranged from $5271 to $52 341. Medication possession ratio was the metric most used to calculate patient adherence, with varying cut-off points defining non-adherence. The main indicators used to measure the cost of non-adherence were total cost or total healthcare cost (83% of studies), pharmacy costs (70%), inpatient costs (46%), outpatient costs (50%), emergency department visit costs (27%), medical costs (29%) and hospitalisation costs (18%). Drummond quality assessment yielded 10 studies of high quality with all studies performing partial economic evaluations to varying extents.

CONCLUSION

Medication non-adherence places a significant cost burden on healthcare systems. Current research assessing the economic impact of medication non-adherence is limited and of varying quality, failing to provide adaptable data to influence health policy. The correlation between increased non-adherence and higher disease prevalence should be used to inform policymakers to help circumvent avoidable costs to the healthcare system. Differences in methods make the comparison among studies challenging and an accurate estimation of true magnitude of the cost impossible. Standardisation of the metric measures used to estimate medication non-adherence and development of a streamlined approach to quantify costs is required.

PROSPERO REGISTRATION NUMBER

CRD42015027338.

Adherence to Maintenance Medications among Older Adults with Chronic Obstructive Pulmonary Disease. The Role of Depression

RATIONALE

Among individuals with chronic obstructive pulmonary disease (COPD), depression is one of the most common yet underrecognized and undertreated comorbidities. Although depression has been associated with reduced adherence to maintenance medications used in other conditions, such as diabetes, little research has assessed the role of depression in COPD medication use and adherence.

OBJECTIVES

The objective of this study was to assess the impact of depression on COPD maintenance medication adherence among a nationally representative sample of Medicare beneficiaries newly diagnosed with COPD.

METHODS

We used a 5% random sample of Medicare administrative claims data to identify beneficiaries diagnosed with COPD between 2006 and 2010. We included beneficiaries with 2 years of continuous Medicare Parts A, B, and D coverage and at least two prescription fills for COPD maintenance medications after COPD diagnosis. We searched for prescription fills for inhaled corticosteroids, long-acting β-agonists, and long-acting anticholinergics and calculated adherence starting at the first fill. We modeled adherence to COPD maintenance medications as a function of new episodes of depression, using generalized estimated equations.

MEASUREMENTS AND MAIN RESULTS

Our primary outcome was adherence to COPD maintenance medications, measured as proportion of days covered. The exposure measure was depression. Both COPD and depression were assessed using diagnostic codes in Part A and B data. Covariates included sociodemographics, as well as clinical markers, including comorbidities, COPD severity, and depression severity. Of 31,033 beneficiaries meeting inclusion criteria, 6,227 (20%) were diagnosed with depression after COPD diagnosis. Average monthly adherence to COPD maintenance medications was low, peaking at 57% in the month after first fill and decreasing to 35% within 6 months. In our adjusted regression model, depression was associated with decreased adherence to COPD maintenance medications (odds ratio, 0.93; 95% confidence interval, 0.89-0.98).

CONCLUSIONS

New episodes of depression decreased adherence to maintenance medications used to manage COPD among older adults. Clinicians who treat older adults with COPD should be aware of the development of depression, especially during the first 6 months after COPD diagnosis, and monitor patients' adherence to prescribed COPD medications to ensure best clinical outcomes.

Adherence and healthcare utilization among older adults with COPD and depression

BACKGROUND AND OBJECTIVE

Adherence to chronic obstructive pulmonary disease (COPD) maintenance medications and antidepressants may reduce healthcare utilization among multimorbid individuals with COPD and depression. We quantified the independent effects of adherence to antidepressants and COPD maintenance medications on healthcare utilization among individuals co-diagnosed with COPD and depression.

PROCEDURES

We conducted a retrospective cohort study using a 2006-2012 5% random sample of Medicare beneficiaries co-diagnosed with COPD and depression who had two or more prescription fills of both COPD maintenance medications and antidepressants. We measured adherence to medications using the proportion of days covered per 30-day period. The primary outcomes were all-cause emergency department (ED) visits and hospitalizations. Beneficiaries were followed over a minimum 12-month follow-up period.

RESULTS

Of the 16,075 beneficiaries meeting inclusion criteria, 21% achieved adherence ≥80% to COPD maintenance medications and 55% achieved adherence ≥80% to antidepressants. Compared to no use and controlling for antidepressant adherence and potential confounders, higher (≥80%) levels of adherence to COPD maintenance medications were associated with decreased risk of ED visits (hazard ratio (HR) 0.79; 95% CI 0.74, 0.83) and hospitalizations (HR 0.82; 95% CI 0.78, 0.87). Similarly, higher levels (≥80%) of adherence to antidepressants resulted in decreased risk of ED visits (HR 0.74; 95% CI 0.70, 0.78) and hospitalizations (HR 0.77; 95% CI 0.73, 0.81) compared to no use.

CONCLUSIONS

Clinicians can assist in the improved management of their multimorbid patients' health by treating depression among patients with COPD and monitoring and encouraging adherence to the regimens they prescribe.

Use of pharmacy records to measure treatment adherence: a critical review of the literature

The current frame of reference on adherence to pharmacotherapy includes a set of behaviors experienced by the user, with observation of the detailed and continuous history of the use of each dose of the medication. Indicators based on pharmacy records have been used to measure adherence. The current review aimed to identify and describe indicators based on pharmacy records and to discuss their adequacy and limitations for measuring adherence. An exploratory literature review was conducted in three databases using the terms "adherence", "pharmacy records/administrative data", and "measure" to compose the descriptors for the selection of 81 articles and the elaboration of a chart with the denomination, sources, methods for calculation, description, and interpretation of the operational and referential meaning of 14 indicators. Given the most recent taxonomy for adherence proposed in the literature, we concluded that the indicators can be useful for identifying patients with medication-seeking behavior-related problems and analysis of persistence. The distance between supply-related events and difficulties in treatment follow-up can influence an analysis based exclusively on the use of these indicators.

Associations Between Cardiovascular Events and Nonergot Dopamine Agonists in Parkinson's Disease

Background

Knowledge of possible cardiovascular risks from Parkinson's disease (PD) medications is critical to informing safe and effective treatment decisions. The objective of our study was to determine whether PD patients treated with nonergot dopamine agonists (DAs) are at increased risk of adverse cardiovascular or cerebrovascular outcomes, relative to PD patients receiving other treatments.

Methods

Matched case-control studies were conducted within a cohort of 14,122 inpatients receiving treatment for PD who were identified in the Cerner Health Facts database. Primary outcomes were associations between nonergot DA use and diagnosis of adverse cardiovascular events (acute myocardial infarction, heart failure [HF], hypotension, and valvulopathy). Secondary outcomes included associations between nonergot DA use and diagnosis of adverse cerebrovascular events (cerebrovascular accident and ischemic stroke) and odds of significant exposure-outcome relationships by patient factors.

Results

HF was the only adverse event that demonstrated a significant association with nonergot DA use. Individuals treated with pramipexole were more likely to be diagnosed with HF, relative to no use (adjusted odds ratio [AOR]: 1.28; 95% confidence interval [CI]: 1.07-1.53). The association between pramipexole and HF was greater among individuals treated with pramipexole monotherapy (relative to levodopa monotherapy) (AOR, 1.50; 95% CI: 1.09-2.06). Compared to nonusers, men and older individuals treated with pramipexole were more likely to be diagnosed with HF.

Conclusions

Results from our study suggest an association between pramipexole use and HF. Findings warrant replication; however, individuals with PD and independent risk factors for, or a history of, HF may benefit from limited use of this drug.

No Difference on Adherence Between Immediate-Release Versus Extended-Release Dopamine Agonists in Uninsured Subjects with Parkinson's Disease

Background

Pharmacological management of subjects with Parkinson's disease (PD) is complex. Regardless of drug selection, adherence is one of the main concerns. Nonadherence is associated with poor symptomatic control and low quality of life. In general, adherence to once-a-day formulations is thought to be better in comparison to 3-times-daily dosing.

Methods

A cross-sectional study was carried out. Consecutive uninsured subjects diagnosed with PD were treated either with an immediate- or extended-release dopamine agonist formulation. Clinical and demographic data were collected. Subjects were assessed using the International Parkinson and Movement Disorder Society UPDRS. Adherence was evaluated using the Morisky-Green test (MGT).

Results

A total of 314 (175 males and 139 females) subjects with PD were included. In regard to treatment, 188 (59.9%) were on an immediate-release dopamine agonist and 126 (40.1%) on an extended-release dopamine agonist. According to the MGT, 21 (6.7%) subjects were classified as nonadherent, 273 (86.9%) with a low adherence, and only 20 (6.4%) were considered with high adherence. Dopamine agonist levodopa equivalent daily dose was higher in the extended-release group (296.6 ± 112.4 vs. 231.3 ± 133.4; P = 0.011); also, these subjects had more years of formal education (12.3 ± 5.2 vs. 9.5 ± 5.2; P = 0.630). No difference in adherence levels was found (P = 0.802) between subjects treated with an immediate-release dopamine agonist and those receiving an extended-release formulation.

Conclusions

Overall adherence in subjects with PD is low. Use of an extended-release over an immediate-release dopamine agonist formulation in this study population is not associated with a better adherence.

Medication adherence in patients with Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder, after Alzheimer's disease, affecting the elderly worldwide. Current therapy for PD is largely based on prescription of drugs that act as either dopamine precursors, dopamine agonists or agents that inhibit key enzymes in the dopamine catabolic pathways. Most of these drugs are administered in tablet or capsule form and can involve multiple daily doses in complex dosing regimens, which contributes to sub-optimal compliance amongst patients. There is evidence to suggest that non-compliance with medications results in perceived poor response to therapy and may ultimately increase direct and indirect health care costs. Medication compliance in PD assumes a particularly important role, given that PD is a progressive, debilitating condition, and once medication is instituted for ameliorating the symptoms of PD, it is lifelong. We included nine research studies in our review of the medical literature, which report the prevalence of significant medication non-compliance in PD, using standard definitions, varies between 10 and 67%. This variation partly reflects differences in defining what clinically significant medication adherence is, the methods used to estimate the scale of the problem and the underlying population heterogeneity. Nevertheless, medication adherence is related to health costs and to the quality of life of patients affected by PD and, indirectly, their carers. Educating patients and their carers is one method of improving patient adherence to therapy. Simplifying drug regimens can also aid in this effort.