The purpose of this study was to investigate the impact of Medicare Part D coverage on medication adherence and health outcomes in dialysis patients. A retrospective analysis (2006-2010) using the United States Renal Data System was conducted for Medicare-eligible dialysis patients. Cardiovascular disease morbidity, healthcare utilization and expenditures, medication adherence, and mortality rates were compared, categorized based on patients’ Part D coverage in 2007 for those who: 1) did not reach the coverage gap (cohort 1); 2) reached the coverage gap but not catastrophic coverage (cohort 2); 3) reached catastrophic coverage (cohort 3); and 4) did not reach the coverage gap but received a low-income subsidy (cohort 4). Cox proportional hazards models, Kaplan-Meier methods, logistic regressions, generalized linear models, and generalized estimating equations were used. A total of 11,732 patients were included as meeting inclusion criteria: 1) cohort 1: 3,678 patients had out-of-pocket drug costs <$799; 2) cohort 2: 4,349 patients had out-of-pocket drug costs between $799 and $3,850; 3) cohort 3: 1,310 patients had out-of-pocket drug costs > $3,850; and 4) cohort 4: the remaining 2,395 patients had out-of-pocket drug costs <$799 but received a low-income subsidy. After adjusting for demographic and clinical factors, patients in cohort 2 and cohort 3 had 42 percent and 36 percent increased risk of cardiovascular disease (odds ratio (OR)=1.42, 95% confidence interval (CI):1.20-1.67; OR=1.38, 95% CI:1.10-1.72); and had 36 percent and 37 percent higher death rates compared to those in cohort 4, respectively (hazard ratio (HR)=1.36, 95% CI:1.27-1.44; HR=1.37, 95% CI:1.27-1.48). Patients in cohort 2 were more likely to be nonadherent to medications for diabetes (OR=1.72, 95% CI:1.48-1.99), hypertension (OR=1.69, 95% CI:1.54-1.85), hyperlipidemia (OR=2.01, 95% CI:1.76-2.29), hyperphosphatemia (OR=1.74, 95% CI:1.55-1.95), and hyperparathyroidism (OR=2.08, 95% CI:1.66-2.60) after reaching the coverage gap. These patients had total health care costs that were $2,644 higher due to increased rates of hospitalization and outpatient visits, despite $2,419 lower pharmacy costs compared to patients in cohort 4 after controlling for covariates (p<0.0001). Reaching the Part D coverage gap was associated with decreased medication adherence and unfavorable clinical and economic outcomes in dialysis patients. / text

Purpose: The purpose of this research was to estimate the impact of Medicare Part D on prescription and medical utilization among Arizona's senior dual eligible population.Methods: Generalized estimating equations were used to analyze changes in utilization among dual eligibles (Arizona Health Care Cost Containment (AHCCCS) beneficiaries between the ages of 66 and 80 as of January 1, 2006) relative to a "comparison" group ineligible for Part D (AHCCCS beneficiaries between the ages of 50 and 62 as of January 1, 2006) for the first two years following the implementation of Part D. Medical and pharmacy claims from AHCCCS from January 1, 2005 to December 31, 2007 were used in this analysis.Results: The dual eligibles and Part D ineligible comparison group were similar in their level and trend of utilization of over-the-counter (OTC) medications and benzodiazepines in the pre-Part D period. Following implementation of Part D, there was an immediate decline in utilization of both OTC medications and benzodiazepines in the dual eligibles relative to the comparison group (p<0.001).Increasing trends for both the dual eligible and comparison group were observed during the pre-Part D period for total prescription utilization, generic medication utilization and antidepressant use. After the implementation of Medicare Part D, utilization of these drug classes was significantly lower among the dual eligibles relative to the comparison group.Trends in physician office visits were similar between the dual eligible group and comparison group for the entire study period. During the first month of Part D, the dual eligibles had a statistically significantly larger increase in physician visits over the previous month relative to the comparison group (p=0.001). The trend in hospitalizations between the two groups significantly differed during the pre-period, precluding meaningful comparisons between the groups for this particular outcome.Conclusion: This study supports the belief that medication use for dual eligible Medicare beneficiaries was disrupted by the transition of outpatient drug benefits from Medicaid to Medicare Part D.

To study the decision-making model behind how physicians making prescribing decisions, we studied the effects of the introduction of Medicare Part D in 2006 on numbers and characteristics of medications prescribed by physicians. We identified a significant increase in overall number of medications prescribed due to Medicare Part D but did not find any effects on the number of antibiotics. The result suggests there exist factors distinguishing antibiotics from other medications that led to a change in incentives to prescribe antibiotics, such as costs of antibiotics resistances. . We also identified the heterogeneity responses to Medicare Part D with respect to physician’s employment status, primary care relationship and patient’s gender and diagnostic categories.

The purpose of this study was to investigate the impact of Medicare Part D on prescription utilization, health services utilization, and health care expenditures in the general Medicare population – as well as Medicare sub-populations, including non-Hispanic blacks (NHBs), Hispanics, near poor individuals, and persons with higher disease burden. A retrospective analysis of Medicare beneficiaries (N=32,228) was conducted using the Medical Expenditure Panel Survey 2002 to 2009 data. Multivariable quantile regression was used to estimate the following outcomes, adjusting for socio-demographic characteristics: 1) number of prescription fills; 2) out-of-pocket (OOP) drug expenditures; 3) total drug expenditures; 4) OOP health care expenditures; 5) total health care expenditures; 6) number of hospitalizations; and 7) number of emergency department (ED) visits between the pre-Part D (2002-2005) and post-Part D (2006-2009) periods. All expenditures were inflation-adjusted to 2009 dollars. The average age of the study sample was 71.0 (SD=14.5). In the general Medicare population, Part D was associated with decreases in OOP drug expenditures (-25.7% to -33.6%; p<0.0001) and OOP health care expenditures (-22.1% to -24.3%; p<0.0001) as well as increases in the number of prescription fills (5.8% to 8.4%; p<0.0001) and total drug expenditures (75th percentile: 5.5%; 90th percentile: 10.2%; p<0.0001). Part D was not associated with changes in total health care expenditures in the general Medicare population. Changes in hospitalizations and ED visits were tested at the 90th percentile, and the results were not statistically significant. In sub-group analyses based on race/ethnicity, non-Hispanic whites (NHWs) experienced more significant reductions in OOP drug and/or health care expenditures when compared with NHBs and Hispanics. Near poor beneficiaries experienced larger reductions in OOP drug expenditures than beneficiaries with middle- to high-income, while Medicare beneficiaries with three or more conditions experienced more substantial reductions in OOP drug and OOP health expenditures after Part D was introduced, compared with those with fewer than three conditions. Part D resulted in increases in medication utilization and reductions in OOP drug and OOP health care expenditures among Medicare beneficiaries. Part D was not associated with differences in total health care spending. The effects of Part D were more pronounced in Medicare subgroups, including NHWs, near poor individuals, and patients with higher chronic disease burden. / text

Using the Health and Retirement Study Panel core files from 1996 to 2014, I analyze how Medicare Part D impacted access to prescription drug coverage by various demographic factors such as race, gender, and income. In Chapter 1, I find the highest take-up rates for those who were white, female, and with higher incomes. However, increases in coverage were high across the board, such that Medicare Part D also improved drug insurance coverage for those who were black, male, and with lower income. Thus, although Medicare Part D did increase prescription drug insurance coverage for seniors across the board, I also find potential for improvement in enrollment for difficult-to-reach groups. Next, Chapter 2 examines the impact of Medicare Part D on mortality. Although I do not find an impact on the life expectancy of respondents as a whole, I do find a significant positive effect for black respondents, indicating that Medicare Part D may have mattered more for disadvantaged groups. The largest impact is for black men, who have an additional 9 percentage point chance of living to age 73 for an additional 8 years of coverage (significant at the 5% level). When looking only at cardiovascular mortality, which is more likely to be influenced by drug coverage, I find improvements in life expectancy for the total population, with stronger effects for minorities and men. Overall, my findings suggest that Medicare Part D did move the needle on its goal: to improve the health of those who, without government intervention, had the most difficulty paying for prescription drugs. Chapter 3 looks at the impact of Medicare Part D prescription drug coverage on cost-related medication adherence, food insecurity, and finances among seniors. It would be reasonable to assume that Medicare Part D, which led to near-universal drug coverage among senior citizens, could allow seniors to shift money previously spent on drug expenditures to other areas. The strongest effect of Medicare Part D is on cost-related medication nonadherence, leading to a 21% decrease for an additional 8 years of Medicare Part D coverage. The impact is even stronger for the black male population (30%). I fail to reject the null hypothesis that Medicare Part D did not reduce food insecurity or household debt. Overall, Medicare Part D appears to have improved the financial stability of seniors.

Previous studies have shown that Medicare Part D beneficiaries tend not to switch plans even though they are encouraged to reevaluate their current plans and switch plans if needed every year. Little is known about why this "plan stickiness" occurs, so there is a critical need to better understand this non-switching behavior. This dissertation project aimed to describe how Part D beneficiaries processed information and how they perceived the plan switching process. It also aimed to describe how switchers and non-switchers were different and to test a model of Part D plan information processing that adapted from Motivation, Opportunity, and Ability (MOA) model. To achieve these objectives, this study had a cross-sectional descriptive design and used a mixed- methods approach consisting of focus groups, interviews, and mailed survey. The qualitative study sample was recruited from two cities in Iowa and transcripts of audio-recorded discussions were analyzed. The population studied in the quantitative phase was voter registered Iowa Part D beneficiaries who were older than 65 and did not receive Low Income Subsidies (LIS). Stratified random sampling was used to identify survey subjects. An eight page survey assessing factors related to Part D plan decisions was developed and mailed to 2,250 subjects, with reminder postcards as well as phone calls used to increase response rate. Finally, confirmatory factor analysis and structural equation modeling (SEM) were used to test a model of Part D plan information processing. A total of 16 participants from three focus groups and three interviews were included in the qualitative analysis. The results indicated that Part D beneficiaries processed different amounts of information even though they made the same decision (i.e. non-switching); whether to receive help from others in reviewing coverage options emerged as an important theme in the plan switching decision. A usable response rate of 22.5 percent was obtained. Of this sample, 264 respondents were non-LIS Part D beneficiaries and were used for further analysis. About one fifth of the sample switched plan between 2012 and 2013, supporting existing literature that has reported a low plan switching rate. Switchers and non-switchers had few demographic differences, but twice as many switchers as non-switchers received help from others in reviewing coverage options. The results from the SEM analysis indicated that those who had lower risk perception about plan switching, higher motivation, and higher self-efficacy were likely to read larger amounts of plan information. They also indicted that higher perceived risk, involvement, and self-efficacy were positively associated with motivation to process plan information. The findings of this dissertation suggest that plan stickiness has two types - active (i.e. informed choice) and passive (i.e. inertia) - depending on the amount of information processed, which was determined by beneficiaries' levels of perceived risk, motivation, self-efficacy, and needs. Furthermore, findings suggest that whether to receive help in understanding plan information may play a large role in leading informed beneficiaries to act on their knowledge and switch plans. The present study is the first to integrate the concept of information processing to understand Part D beneficiaries' plan switching decisions and the first to examine psychological factors affecting beneficiaries' information processing as well as their plan switching decisions. Study findings will help policy makers developing efficient communication strategies with beneficiaries to help them to make informed choices.

Since January 2006 Medicare beneficiaries have the option to purchase prescription drug benefits from Medicare under the Part D program. The addition of outpatient drugs to the Medicare programs reflects Congress’ recognition of the fundamental change in recent years in how medical care is delivered in the U.S. It recognizes the vital role of prescription drugs in the health care delivery system and the need to modernize Medicare to assure their availability to Medicare beneficiaries. The Medicare Prescription Drug Improvement and Modernization Act of 2003 (MMA) created the Medicare drug benefit and specified a standard plan. The law also enables plans to offer alternative benefit packages that are either actuarially equivalent or provide enhanced benefits above the basic benefits. A majority of these alternative plans offer multitiered formulary where different medications have different patient copayments. Different from traditional Medicare, Part D benefits are provided by private sector plans through a competitive bidding process. Firms submit a bid to the Center for Medicare and Medicaid Services (CMS) which represents the expected cost to the firm for providing basic benefits to an individual of average health. The competition between plans was expected to drive premiums down toward marginal cost, ensuring that the beneficiaries receive maximum benefits for a given public expenditure (Biles et al. 2004). This dissertation examines the stand-alone Medicare Prescription Drug Plans (PDPs) bid and premium from the following perspectives using the 2006-2008 PDP data. First, we examine the use of multiple-tier copayment structures. In particular, we tend to discover the relationship between enrollee cost sharing at each tier and prescription drug plan (PDP) bids. Bids are equivalent to the total premiums charged by an insurer. This includes the premium paid by the consumer and the portion paid by the federal government. Further, we decompose plan bid and premium changes between 2006 and 2008 into two components, the proportion due to changes in plan characteristics and the proportion due to changes in marginal price. By doing so, we estimate whether the actuarial methods used to price those characteristics play a role in explaining the plan bid and premium difference across years.  Finally, we measure the Medicare beneficiaries’ sensitivity to price in the PDP market, specifically the elasticity and semi-elasticity of enrollment with respect to PDP premium.

Anecdotal descriptions and small studies have reported decreasing reimbursements from Medicare Part D sponsors and commercial third-party payers, resulting in decreased gross margins for independent pharmacies; however, reports are inconclusive regarding which payer more greatly affects independent pharmacies’ financial viability. Using 2006-2009 prescription claims data collected by a pharmacy switching company, the purpose of this study was to calculate and describe estimated reimbursement formulas and mean gross margins to assess the relative impact of these two payer groups. The study evaluated a total of 2,929,696 prescription claims paid for by Medicare Part D sponsors (n = 1,830,896) and commercial third-party payers (n = 1,098,800). The prescriptions were dispensed by 418 Texas independent pharmacies to 192,968 patients aged 65 to 94. Between 2008 and 2009, the median ingredient reimbursement ranged from AWP-17% to AWP-15% for Part D sponsors and from AWP-17.44% to AWP-15% for commercial third-party payers. The median dispensing fee ranged from $1.50 to $2.00 for Part D sponsors and from $1.10 to $2.00 for commercial third-party payers. For all payers, the median dispensing fee and median ingredient reimbursement decreased or was stagnant. Similarly, aggregate percent gross margin (calculated using the payers’ estimates of acquisition cost) decreased for both payer types between 2007 and 2009, with the mean gross margin of 4.0 percent earned for Part D prescriptions being higher than the 3.7 percent earned for commercial third-party prescriptions. In the same timeframe, the mean aggregate percent gross margin ranged from 2.8 percent to 6.0 percent among the five most popular Part D sponsors in the sample, and from 2.4 percent to 5.1 percent among the five most popular commercial third-party payers. The generic dispensing ratio explained a portion of the variance between and among payers. This study shows that significant variation exists in reimbursement formulas and percent gross margin between and among several of the most popular Part D sponsors and commercial third-party payers and supports pharmacy assertions that reimbursements from both payer types are decreasing. Pharmacies can respond to these pressures by being more conscientious of their business’ margins when reviewing contracts and increasing the proportion of generic drugs dispensed. / text

The objective of this dissertation is to evaluate whether two different types of policy interventions in the United States are associated with health service utilization and economic outcomes. Paper 1: The number of government lawsuits accusing pharmaceutical companies of off-label marketing has risen in recent years. We use Medicare and Medicaid claims data to evaluate how an off-label marketing lawsuit and its accompanying media coverage affected utilization and spending on gabapentin as well as other anticonvulsant medications. In this interrupted time series analysis of dual eligible patients with bipolar disorder, we found that the lawsuit and accompanying media coverage corresponded with a decrease in market share of gabapentin, a substitution of newer and expensive anticonvulsants, and a substantial increase in overall spending on anticonvulsants. Paper 2: Medicare Part D was a major expansion of Medicare benefits to cover pharmaceuticals. There were initial concerns about how the dually eligible population who previously had drug coverage through Medicaid would fare after transitioning to Part D plans. Using a nationally representative longitudinal panel survey of Medicare Beneficiaries that are dually eligible for Medicaid, we investigated whether differences in generosity of Medicaid drug benefits were associated with differential changes in drug utilization and out-of-pocket spending for duals after they transitioned to Part D. Our finding suggest that those who previously encountered a monthly drug cap prior to Part D implementation experienced a differentially higher increase in annual prescription drug fills compared with those who did not face a cap.

Class of 2014 Abstract / Specific Aims: To identify reasons that an angiotensin converting enzyme inhibitor (ACEi) would not be indicated in diabetic patients with repeated clinical alerts to add ACEi therapy for preservation of renal function and/or hypertension. In addition, to identify if these repeated clinical alerts to add ACEi therapy are appropriate. Methods: Eligible patient charts were reviewed by researchers using a data dictionary to complete a standardized spreadsheet with patient demographic information (age, gender, and location), type of diabetes mellitus, evidence indicative of comorbid hypertension, action taken by pharmacist in response to clinical alert (letter sent to patient and letter sent to prescriber), and rationale of that action. This data, along with SOAP notes of patient interactions, was used by researchers to classify the repeated clinical alert as appropriate or inappropriate. Main Results: There were a total of 200 charts reviewed (male n = 61 (30.5%), female n = 139 (69.5%), mean age = 70 ± 11 years). Reasons for not contacting patients again include previous failure or adverse drug reaction (n = 62, 31.0%), patient did not meet call script requirements (n = 55, 27.5%), patient did not have diabetes or hypertension (n = 20, 10.0%), potential drug-disease interaction (n = 17, 8.5%), overlapping or previously addressed alerts (1.9%), or documentation was provided for “other” reasons (n = 43, 21.5%). The previous failure or adverse drug reaction rationale was appropriate in 32 of 62 repeated clinical alerts (52%; χ2= 10.15). The patient did not have diabetes or hypertension rationale was appropriate in 11 of 20 repeated clinical alerts (55%, χ2= 2.72). The potential drug-disease interaction rationale was appropriate in 3 of 17 repeated clinical alerts (8%, χ2= 9.89). The patient did not meet call script requirements rationale was appropriate in 31 of 55 repeated clinical alerts (56%, χ2= 6.91). The overlapping or previous alerts rationale was appropriate in 2 of 3 repeated clinical alerts (67%, χ2= 0.18). The “other” rationale were appropriate in 22 of 43 repeated clinical alerts (51%, χ2= 7.21) Overall, retrigger alerts were considered appropriate 50.5% of the time compared to the predicted value of 90% (χ2= 347 > critical value = 3.84 for p = 0.05 Conclusion: There are multiple reasons pharmacists do not recommend initiating ACEi therapy in patients with diabetes. Although the Medication Management Center (MMC) has rationale of these reasons documented after individual patient interactions, there are still several reasons why a retrigger alert would be appropriate despite that rationale. In addition, retrigger alerts were not considered appropriate as frequently as expected.