Low-income Subsidy Status Research Articles

Association of Medicare Part D low-income cost subsidy program enrollment with increased fill adherence to clopidogrel after coronary stent placement.

To determine the association between enrollment in the Medicare Part D low-income subsidy (LIS) program, which reduces out-of-pocket medication costs, and fill adherence to the antiplatelet drug clopidogrel after coronary stent placement. Retrospective cohort study. Pharmacy claims database of a large national Medicare Part D insurer. We selected a total of 2967 beneficiaries of a national Medicare Part D plan who had a coronary stent placed between April and December 2006 and were prescribed clopidogrel but were not preexisting users of clopidogrel. Of these patients, 504 were enrolled in the LIS program and 2463 were not. We defined LIS status as enrollment in the LIS program at any point during the 12 months after the procedure. We examined the association between LIS status and good medication fill adherence to clopidogrel, defined as proportion of days covered of 80% or more, or discontinuation of clopidogrel over the 12-month window starting from the date of their stent placement. We also identified patients with claims-based diagnoses of major bleeding events while taking clopidogrel. For those patients, we calculated fill adherence only for the period between medication initiation and the onset of major bleeding and/or did not classify them as having inappropriately discontinued the medication. We created a propensity score predicting the propensity of being eligible for the LIS benefit and used inverse propensity score weighting with regression adjustment to generate estimates of the effect parameters. LIS enrollment was associated with a higher predicted likelihood of good clopidogrel fill adherence after stent placement (54.8% for LIS enrollees vs 47.6% for non enrollees; p=0.008). No significant difference was noted between the two groups in predicted risk of discontinuing clopidogrel after stent placement (18.3% for LIS enrollees vs 21.0% for non enrollees; p=0.21). The LIS benefit was associated with better clopidogrel fill adherence after stent placement. Although clopidogrel is now available in generic form, our work underscores the need for efforts to identify and enroll patients in the LIS benefit who require costly antiplatelet medications for coronary heart disease.

Association between dispensing channel and medication adherence among medicare beneficiaries taking medications to treat diabetes, high blood pressure, or high blood cholesterol.

Medication adherence, defined as taking medications as prescribed, is a key component in controlling disease progression and managing chronic illnesses such as diabetes, hypertension, and high blood cholesterol. These diseases constitute 3 of the top 5 most prevalent conditions among Medicare beneficiaries, warranting further attention to find ways to promote better medication adherence. The scientific literature has established the clinical and financial benefits of medication adherence and the role of dispensing channel in impacting adherence to medications. However, a common limitation in channel-adherence studies is the failure to control for healthy adherer effect (HAE), referring to individuals who are likely to engage proactively in activities that improve their adherence. Healthier individuals may choose the home-delivery channel to ensure continuity in their medication regimens and to minimize obstacles to adherence, such as inadequate access, inconvenience, and financial concerns. Thus, better medication adherence in home delivery may reflect healthier patients' predisposition to self-select for home delivery options. To accurately attribute the impact of dispensing channel on adherence, research would need to control for bias from a patient's predisposition to be adherent. To examine the association of pharmacy dispensing channel (home delivery or retail pharmacy) with medication adherence for Medicare Part D beneficiaries taking medications for diabetes, hypertension, or high blood cholesterol, while controlling for low-income subsidy status, differences in days supply, and prior adherence behavior (PAB) as a way to partly control for HAE. A retrospective analysis using de-identified pharmacy claims data from a large national pharmacy benefits manager between October 2010 and December 2012. Continuously eligible Medicare Part D beneficiaries (Medicare Advantage and prescription drug plans participants only) aged 65 years or older who had an antidiabetic, antihypertensive, or antihyperlipidemic prescription claim between October and December 2010, were identified and followed for the next 2 years. Those enrolled in a home delivery auto refill program were excluded from this analysis. Multivariate logistic regression was used to evaluate the impact of dispensing channel on medication adherence, controlling for differences in demographics, low-income subsidy status, disease burden, and drug-use pattern. Patients with a proportion of days covered of ≥ 80% were considered to be adherent. The analysis controlled for PAB by using patients' adherence status in the year 2011. The final analytical samples consisted of 150,389 diabetic patients, 615,618 hypertension patients, and 358,795 high blood cholesterol patients. The adjusted odds of being adherent for beneficiaries using home delivery were 1.25 times higher (CI = 1.20-1.30) for diabetes medications, 1.29 times higher (CI = 1.27-1.32) for hypertension medications, and 1.26 times higher (CI = 1.23-1.29) for high blood cholesterol medications, compared with beneficiaries using retail channels to obtain their prescriptions. PAB was the strongest contributor to the odds of a patient being adherent across all 3 therapy classes, ranging from odds ratio of 4.48 to 8.09. After excluding patients who received any prescriptions via home delivery auto refill programs and controlling for PAB, differences in days supply, low-income subsidy status, demographics, and disease burden, Medicare beneficiaries who use home delivery for antidiabetics, antihypertensives, or antihyperlipidemics have a greater likelihood of being adherent than patients who fill their prescriptions at retail. The results of this study provide evidence that where medications are received may impact adherence, even when controlling for PAB. Use of the home delivery dispensing channel may be an effective method to improve adherence for Medicare beneficiaries.

Utilization and Costs of Medications Associated With CKD Mineral and Bone Disorder in Dialysis Patients Enrolled in Medicare Part D

Information is limited regarding utilization patterns and costs for chronic kidney disease-mineral and bone disorder (CKD-MBD) medications in Medicare Part D-enrolled dialysis patients. Retrospective cohort study. Annual cohorts of dialysis patients, 2007-2010. Cohort year, low-income subsidy status, and dialysis provider. Utilization and costs of prescription phosphate binders, oral and intravenous vitamin D analogues, and cinacalcet. Using logistic regression, we calculated adjusted odds of medication use for low-income subsidy versus non-low-income subsidy patients and for patients from various dialysis organizations, and we report per-member-per-month and average out-of-pocket costs. Phosphate binders (∼83%) and intravenous vitamin D (77.5%-79.3%) were the most commonly used CKD-MBD medications in 2007 through 2010. The adjusted odds of prescription phosphate-binder, intravenous vitamin D, and cinacalcet use were significantly higher for low-income subsidy than for non-low-income subsidy patients. Total Part D versus CKD-MBD Part D medication costs increased 22% versus 36% from 2007 to 2010. For Part D-enrolled dialysis patients, CKD-MBD medications represented ∼50% of overall net Part D costs in2010. Inability to describe utilization and costs of calcium carbonate, an over-the-counter agent not covered under Medicare Part D; inability to reliably identify prescriptions filled through a non-Part D reimbursement or payment mechanism; findings may not apply to dialysis patients without Medicare Part D benefits or with Medicare Advantage plans, or to pediatric dialysis patients; could identify only prescription drugs dispensed in the outpatient setting; inability to adjust for MBD laboratory values. Part D net costs for CKD-MBD medications increased at a faster rate than costs for all PartDmedications in dialysis patients despite relatively stable use within medication classes. In a bundled environment, there may be incentives to shift to generic phosphate binders and reduce cinacalcet use.

Comparative Effectiveness of Calcium Acetate and Sevelamer on Clinical Outcomes in Elderly Hemodialysis Patients Enrolled in Medicare Part D

Phosphate binders are an important therapeutic option for managing hyperphosphatemia in hemodialysis patients. Whether sevelamer confers a survival advantage over calcium acetate is unclear. Observational cohort study using US Renal Data System (USRDS) data linked to Medicare Part D prescription drug data. Medicare-enrolled elderly incident hemodialysis patients initiating calcium acetate or sevelamer therapy between July 1, 2006, and March 31,2011. Prescription for sevelamer (hydrochloride or carbonate) or calcium acetate. All-cause and cardiovascular-related mortality, hospital admissions and hospital days assessed from Medicare Parts A, B, and D claims and other USRDS data. The sevelamer and calcium-acetate groups included 16,916 and 18,335 patients, respectively. After multivariable adjustment, all-cause (21.9 vs 21.8 deaths/100 patient-years; adjusted HR, 0.97; 95% CI, 0.94-1.03) and cardiovascular (8.7 vs 8.6 deaths/100 patient-years; HR, 0.99; 95% CI, 0.93-1.04) mortality did not differ significantly between the sevelamer and calcium-acetate (referent) groups. Mortality results in propensity score-matched cohorts showed significantly lower risk of death in sevelamer- than in calcium-acetate-treated patients (HR, 0.94; 95% CI, 0.91-0.98). Mortality results from additional analyses including only patients with low-income subsidy status were consistent with results from analyses including patients with and without low-income subsidy status. There were no significant differences between the sevelamer and calcium-acetate groups for all-cause and cardiovascular-related first hospitalization, multiple hospitalizations, and hospital days. Results may not be applicable to younger patients; information about laboratory data and over-the-counter calcium-containing binders was lacking. Relative to treatment with calcium acetate, treatment with sevelamer was associated with similar or slightly lower risk of death and similar risk of hospitalization in elderly incident hemodialysis patients.

The Relationship Between the Low‐Income Subsidy and Cost‐Related Nonadherence to Drug Therapies in Medicare Part D

To examine the relationship between receiving the Medicare Part D low-income subsidy (LIS) and cost-related medication nonadherence (CRN). Cross-sectional. Medicare Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey collected in spring 2007. Part D-enrolled Medicare beneficiaries who responded to the CAHPS survey. Respondents were categorized into three LIS groups: deemed LIS (Medicare and Medicaid dual-eligible and individuals receiving Supplemental Security Income), LIS applicants (other low-income individuals who applied for and received LIS), and non-LIS. Adjusted logistic models were used to assess the likelihood of CRN according to LIS status. Sample weights were applied in all analyses to account for complex sampling design. Of 171,573 Part D-enrolled respondents (weighted N = 14,572,827; response rate 48%), 17.2% reported CRN. Specifically, 14.7% of non-LIS respondents, 22.2% of deemed-LIS respondents, and 24.0% of LIS applicants reported CRN. LIS groups had higher unadjusted odds of CRN than the non-LIS respondents, but fully adjusted odds of CRN were lower in the deemed-LIS (adjusted odds ratio = 0.66, 95% confidence interval = 0.59, 0.74) than the LIS applicants or the non-LIS respondents. Subgroup analyses revealed that sociodemographic and health-related characteristics were associated with higher CRN in all three groups. The lower adjusted odds of CRN in deemed-LIS is reassuring, suggesting that autoenrollment provides meaningful assistance in removing cost-related barriers to medication use, but certain sociodemographic characteristics were associated with higher odds of CRN. Efforts to improving outreach to these subgroups and tracking of CRN are warranted.

How Medicare Part D benefit phases affect adherence with evidence-based medications following acute myocardial infarction.

Assess impact of Medicare Part D benefit phases on adherence with evidence-based medications after hospitalization for an acute myocardial infarction. Random 5 percent sample of Medicare beneficiaries. Difference-in-difference analysis of drug adherence by AMI patients stratified by low-income subsidy (LIS) status and benefit phase. Subjects were identified with an AMI diagnosis in Medicare Part A files between April 2006 and December 2007 and followed until December 2008 or death (N=8,900). Adherence was measured as percent of days covered (PDC) per month with four drug classes used in AMI treatment: angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs), beta-blockers, statins, and clopidogrel. Monthly exposure to Part D benefit phases was calculated from flags on each Part D claim. For non-LIS enrollees, transitioning from the initial coverage phase into the Part D coverage gap was associated with statistically significant reductions in mean PDC for all four drug classes: statins (-7.8 percent), clopidogrel (-7.0 percent), beta-blockers (-5.9 percent), and ACE inhibitor/ARBs (-5.1 percent). There were no significant changes in adherence associated with transitioning from the gap to the catastrophic coverage phase. As the Part D doughnut hole is gradually filled in by 2020, Medicare Part D enrollees with critical diseases such as AMI who rely heavily on brand name drugs are likely to exhibit modest increases in adherence. Those reliant on generic drugs are less likely to be affected.

Association of Chronic Obstructive Pulmonary Disease Maintenance Medication Adherence With All-Cause Hospitalization and Spending in a Medicare Population

BackgroundAlthough maintenance medications are a cornerstone of chronic obstructive pulmonary disease (COPD) management, adherence remains suboptimal. Poor medication adherence is implicated in poor outcomes with other chronic conditions; however, little is understood regarding links between adherence and outcomes in COPD patients. ObjectiveThis study investigates the association of COPD maintenance medication adherence with hospitalization and health care spending. MethodsUsing the 2006 to 2007 Chronic Condition Warehouse administrative data, this retrospective cross-sectional study included 33,816 Medicare beneficiaries diagnosed with COPD who received at least 2 prescriptions for ≥1 COPD maintenance medications. After a 6-month baseline period (January 1, 2006 to June 30, 2006), beneficiaries were followed through to December 31, 2007 or death. Two medication adherence measures were assessed: medication continuity and proportion of days covered (PDC). PDC values ranged from 0 to 1 and were calculated as the number of days with any COPD maintenance medication divided by duration of therapy with these agents. The association of adherence with all-cause hospital events and Medicare spending were estimated using negative binomial and γ generalized linear models, respectively, adjusting for sociodemographics, Social Security disability insurance status, low-income subsidy status, comorbidities, and proxy measures of disease severity. ResultsImproved adherence using both measures was significantly associated with reduced rate of all-cause hospitalization and lower Medicare spending. Patients who continued with their medications had lower hospitalization rates (relative rate [RR] = 0.88) and lower Medicare spending (–$3764), compared with patients who discontinued medications. Similarly, patients with PDC ≥0.80 exhibited lower hospitalization rates (RR = 0.90) and decreased spending (–$2185), compared with patients with PDC <0.80. ConclusionsCOPD patients with higher adherence to prescribed regimens experienced fewer hospitalizations and lower Medicare costs than those who exhibited lower adherence behaviors. Findings suggested the clinical and economic importance of medication adherence in the management of COPD patients in the Medicare population.

P-951 - Medicare Part D, generic prescribing and adherence to antidepressant therapy

Introduction In the U.S., Medicare Part D coverage gap poses concern for antidepressant adherence, but wide availability of generic antidepressants may mitigate the effect. Objectives and aims To assess the effects of coverage gap and generic prescribing on antidepressant adherence among a cohort of Medicare patients experiencing a new episode of depression. Methods We used 2007 Medicare Part D drug event file to examine antidepressant use over the 6 months following antidepressant initiation. We estimated Cox proportional hazard models to assess the effects of the two factors on the risk of antidepressant treatment disruption. We estimated mixed-effects linear models to assess the effects on monthly days of antidepressant possession. All analyses were stratified by Part D low-income subsidy (LIS) status and Medicare entitlement (aged vs. disabled). Results Receiving a generic (vs. brand) antidepressant on the first script was associated with a significantly reduced risk of treatment disruption across all four populations: hazard ratios ranged from 0.66 (p = 0.006) among disabled patients not receiving LIS to 0.88 (p = 0.020) among aged patients receiving LIS. For patients not receiving LIS, experience of coverage gap was associated with increased risk of disruption only among the disabled (hazard ratio = 2.15, p = 0.006). Analysis of monthly antidepressant possession produced consistent results and indicated that the beneficial effect of generic first script was comparable with or outweighed the detrimental effect of coverage gap. Conclusions Part D coverage gap adversely affected antidepressant adherence by disabled patients not receiving LIS. Increased generic prescribing may help improve adherence among all patients.

Utilization and Costs of Cardiovascular Disease Medications in Dialysis Patients in Medicare Part D

Cardiovascular disease (CVD) is a major source of mortality and morbidity in dialysis patients. Population-level descriptions of CVD medication use are lacking in this population. Retrospective cohort study. Adult dialysis patients in the United States, alive on December 31, 2006, with Medicare Parts A and B and enrollment in Medicare Part D continuously in 2007. CVDs and demographic characteristics. ≥1 prescription fill during follow-up (2007). Average out-of-pocket costs per user per month and average total drug costs per member per month were calculated. Of 225,635 dialysis patients who met inclusion criteria during the entry period, 70% (n = 158,702) had continuous Part D coverage during follow-up. Of these, 76% received the low-income subsidy. β-Blockers were the most commonly used CVD medication (64%), followed by renin-angiotensin system inhibitors (52%), calcium channel blockers (51%), lipid-lowering agents (44%), and α-agonists (23%). Use varied by demographics, geographic region, and low-income subsidy status. For CVD medications, mean out-of-pocket costs per user per month were $3.44 and $49.59 and mean total costs per member per month were $124.02 and $110.32 for patients with and without the low-income subsidy, respectively. Information was available for only filled prescriptions under the Part D benefit; information for clinical contraindications was lacking, information for over-the-counter medications was unavailable, and medication adherence and persistence were not examined. Most Medicare dialysis patients in 2007 were enrolled in Part D, and most enrollees received the low-income subsidy. β-Blockers were the most used CVD medication. Total costs of CVD medications were modestly higher for low-income subsidy patients, but out-of-pocket costs were much higher for patients not receiving the subsidy. Further study is warranted to delineate sources of variation in the use and costs of CVD medications across subgroups.