J Samantha Shoemaker

Publications (12)31.83 Total impact

• Article: Regions with higher medicare part d spending show better drug adherence, but not lower medicare costs for two diseases.

  Bruce Stuart, J Samantha Shoemaker, Mingliang Dai, Amy J Davidoff
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  ABSTRACT: A quarter-century of research on geographic variation in Medicare costs has failed to find any positive association between high spending and better health outcomes. We conducted this study using a 5 percent random sample of Medicare beneficiaries with diabetes or heart failure in 2006 and 2007 to see whether there was any correlation between geographic variation in Part D spending and good medication-taking behavior-and, if so, whether that correlation resulted in reduced Medicare Parts A and B spending on diabetes and heart failure treatments. We found that beneficiaries residing in areas characterized by higher adjusted drug spending had significantly more "therapy days"-days with recommended medications on hand-than did beneficiaries in lower-spending areas. However, we did not find that this factor translated into short-term savings in Medicare treatment costs for these two diseases. This result might not be surprising, since returns from medication adherence can take years to manifest. At the same time, discovering which regional factors are responsible for differences in drug spending and medication practices should be a high priority. If the observed differences are related to poor physician communication or lack of good care coordination, then appropriately designed policy tools-including accountable care organizations, medical homes, and provider quality reporting initiatives-might help address them.
  Health Affairs 01/2013; 32(1):120-6. · 4.31 Impact Factor
• Article: Out-of-pocket health care expenditure burden for medicare beneficiaries with cancer.

  Amy J Davidoff, Mujde Erten, Thomas Shaffer, J Samantha Shoemaker, Ilene H Zuckerman, Naimish Pandya, Ming-Hui Tai, Xuehua Ke, Bruce Stuart
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  ABSTRACT: BACKGROUND: There is increasing concern regarding the financial burden of care on cancer patients and their families. Medicare beneficiaries often have extensive comorbidities and limited financial resources, and may face substantial cost sharing even with supplemental coverage. In the current study, the authors examined out-of-pocket (OOP) spending and burden relative to income for Medicare beneficiaries with cancer. METHODS: This retrospective, observational study pooled data for 1997 through 2007 from the Medicare Current Beneficiary Survey linked to Medicare claims. Medicare beneficiaries with newly diagnosed cancer were selected using claims-based diagnoses. Generalized linear models were used to estimate OOP spending. Logistic regression models identified factors associated with a high OOP burden, defined as spending > 20% of one's income during the cancer diagnosis and subsequent year. RESULTS: The cohort included 1868 beneficiaries with and 10,047 without cancer. Compared with the noncancer cohort, cancer patients were older, had more comorbidities, and were more likely to lack supplemental coverage. The mean OOP spending for cancer patients was $4727. Cancer patients faced an adjusted $976 (P < .01) incremental OOP spending. Greater than one-quarter (28%) of beneficiaries with cancer experienced a high OOP burden compared with 16% of beneficiaries without cancer (P < .001). Supplemental insurance and higher income were found to be protective against a high OOP burden, whereas assets, comorbidity, and receipt of cancer-directed radiation and antineoplastic therapy were associated with a higher OOP burden. CONCLUSIONS: Medicare beneficiaries with cancer face a higher OOP burden than their counterparts without cancer; some of the higher burden was explained by the higher comorbidity burden and lack of supplemental insurance noted among these patients. Financial pressures may discourage some elderly patients from pursuing treatment. Cancer 2012. © 2012 American Cancer Society.
  Cancer 12/2012; · 4.77 Impact Factor
• Article: Use and Spending on Antineoplastic Therapy for Medicare Beneficiaries With Cancer.

  Amy J Davidoff, Thomas Shaffer, Mujde Z Erten, J Samantha Shoemaker, Ilene H Zuckerman, Naimish Pandya, Bruce C Stuart, Lynda G Bryant-Comstock, Rahul Shenolikar
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  ABSTRACT: BACKGROUND:: Oral antineoplastic drugs, not generally covered by Medicare Part B, have assumed an increasingly important role in cancer treatment. OBJECTIVE:: We examined use and spending on infused/injected (Part B covered) and non-Part B antineoplastic agents in a Medicare beneficiary population with cancer, and the effect of supplemental insurance. RESEARCH DESIGN:: This retrospective, observational study used pooled 1997-2007 data from the Medicare Current Beneficiary Survey, linked to Medicare claims. Logistic regression models identified factors associated with antineoplastic use. Generalized linear models were used to estimate spending among antineoplastic users. Population studied: A total of 1836 Medicare beneficiaries with newly diagnosed cancer were selected based on the presence of claims-based diagnoses after a 12-month washout period. RESULTS:: Five hundred fifty-nine (31.0%) Medicare beneficiaries received antineoplastic therapy; 395 (21.3%) used Part B, 253 (14.6%) used non-Part B antineoplastics. Spending per user was $7841 (any), $10,364 (Part B), and $1535 for non-Part B antineoplastics. Supplemental insurance was associated with antineoplastic use. Primary cancer site and age were key predictors of spending among users. Spending on non-Part B antineoplastics increased during 2006-2007 relative to 2004-2005 but time trends were not significant in multivariate analysis. CONCLUSIONS:: Antineoplastic therapy use by Medicare beneficiaries is sensitive to the presence but not type of supplemental insurance. Non-Part B therapy was used by a relatively large proportion of beneficiaries with cancer receiving therapy, although spending was less than for Part B therapy. Monitoring the role of supplemental insurance, and particularly the role of Medicare Part D is a critical area for ongoing research.
  Medical care 12/2012; · 3.24 Impact Factor
• Article: How Does Drug Treatment for Diabetes Compare between Medicare Advantage Prescription Drug Plans (MAPDs) and Stand-Alone Prescription Drug Plans (PDPs)?

  Mujde Z Erten, Bruce Stuart, Amy J Davidoff, J Samantha Shoemaker, Lynda Bryant-Comstock, Rahul Shenolikar
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  ABSTRACT: OBJECTIVE: To compare the use of guideline-recommended prescription medications for diabetes among Medicare beneficiaries enrolled in stand-alone prescription drug plans (PDPs) with Medicare Advantage prescription drug plans (MAPDs) in the presence of potential selection bias. DATA SOURCES/STUDY SETTING: Centers for Medicare and Medicaid Services' Chronic Condition Data Warehouse (2006, 2007). STUDY DESIGN: Retrospective cross-sectional comparison of drug use and proportion of days covered (PDC) for oral-antidiabetics, ACE-inhibitors/ARBs, and antihyperlipidemics among PDP and MAPD enrollees with diabetes. We estimated "naïve" regression models assuming exogenous plan choice and two-stage residual inclusion (2SRI) models to study endogeneity in choice of Part D plan type. DATA COLLECTION/EXTRACTION METHODS: We identified 111,290 diabetics based on ICD-9 codes in Medicare claims from a random 5 percent sample of Medicare beneficiaries in 2005 excluding dual eligibles. PRINCIPAL FINDINGS: The naïve regression models indicated lower probability of drug use for oral-antidiabetics (-4 percent; p < .001) and ACE-inhibitors/ARBS (-2 percent; p = .004) among PDP enrollees, but their PDC was higher (3-5 percent) for all drug classes (p < .001). 2SRI models produced no significant differences in any-use equations, but significantly higher PDC values for PDP enrollees for oral-antidiabetics and ACE-inhibitors/ARBs. CONCLUSIONS: We found similar overall use of recommended drugs in diabetes treatment and no consistent evidence of favorable or adverse selection into PDPs and MAPDs.
  Health Services Research 12/2012; · 2.16 Impact Factor
• Article: Impact of Part D Low-income Subsidies on Medication Patterns for Medicare Beneficiaries With Diabetes.

  Bruce Stuart, Xianghua Yin, Amy Davidoff, Linda Simoni-Wastila, Ilene Zuckerman, J Samantha Shoemaker, Jalpa Doshi
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  ABSTRACT: : It is not known whether low-income subsidies (LIS) under Medicare Part D help beneficiaries overcome impediments to medication use associated with poor socioeconomic status and high disease burden. : To compare Medicare beneficiaries with LIS and Medicaid (duals), LIS without dual eligibility, and non-LIS recipients on use of medications recommended in diabetes treatment. : Fixed-effect comparisons among beneficiaries in the same Part D plans in 2006-2007. : Nationally representative sample of enrollees in Part D prescription drug plans. A total of 109,292 beneficiaries were in 204 prescription drug plans; 47.5% non-LIS, 44.4% duals, and 8.1% nondual LIS recipients. : Medications included antidiabetic agents, renin-angiotensin-aldosterone system inhibitors, and antihyperlipidemics. Drug use was measured by exposure, duration of therapy, and medication possession ratio. : The LIS dual cohort had significantly higher comorbidity compared with non-LIS comparisons, LIS nonduals were significantly more likely to take medications in all 3 drug classes compared with non-LIS recipients, but differences were small (between 2% and 4%; P<0.05). Non-LIS recipients and duals had equivalent exposure to any antidiabetic drug and antihyperlipidemics, but duals were 3% less likely to receive renin-angiotensin-aldosterone system inhibitors compared with non-LIS recipients (P<0.05). Small differences in adjusted values for duration of therapy and medication possession ratio among the 3 cohorts were also observed, none of which were clinically meaningful. : Similarities in medication utilization among Part D enrollees with and without LIS coverage supports the program objective of providing enhanced access to needed medications for diverse groups of Medicare beneficiaries.
  Medical care 11/2012; 50(11):913-9. · 3.24 Impact Factor
• Article: Medication adherence and Medicare expenditure among beneficiaries with heart failure.

  Ruth Lopert, J Samantha Shoemaker, Amy Davidoff, Thomas Shaffer, Abdulla M Abdulhalim, Jennifer Lloyd, Bruce Stuart
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  ABSTRACT: Objectives: To (1) measure utilization of and adherence to heart failure medications and (2) assess whether better adherence is associated with lower Medicare spending. Study Design: Pooled cross-sectional design using six 3-year cohorts of Medicare beneficiaries with congestive heart failure (CHF) from 1997 through 2005 (N = 2204). Methods: Adherence to treatment was measured using average daily pill counts. Bivariate and multivariate methods were used to examine the relationship between medication adherence and Medicare spending. Multivariate analyses included extensive variables to control for confounding, including healthy adherer bias. Results: Approximately 58% of the cohort were taking an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB), 72% a diuretic, 37% a beta-blocker, and 34% a cardiac glycoside. Unadjusted results showed that a 10% increase in average daily pill count for ACE inhibitors or ARBs, beta-blockers, diuretics, or cardiac glycosides was associated with reductions in Medicare spending of $508 (not significant [NS]), $608 (NS), $250 (NS), and $1244 (P <.05), respectively. Estimated adjusted marginal effects of a 10% increase in daily pill counts for beta-blockers and cardiac glycosides were reductions in cumulative 3-year Medicare spending of $510 to $561 and $750 to $923, respectively (P <.05). Conclusions: Higher levels of medication adherence among Medicare beneficiaries with CHF were associated with lower cumulative Medicare spending over 3 years, with savings generally exceeding the costs of the drugs in question.
  The American journal of managed care 09/2012; 18(9):556-63. · 2.46 Impact Factor
• Article: Simulated value-based insurance design applied to statin use by Medicare beneficiaries with diabetes.

  Amy Davidoff, Ruth Lopert, Bruce Stuart, Thomas Shaffer, Jennifer T Lloyd, J Samantha Shoemaker
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  ABSTRACT: To examine cost responsiveness and total costs associated with a simulated "value-based" insurance design for statin therapy in a Medicare population with diabetes. Four-year panels were constructed from the 1997-2005 Medicare Current Beneficiary Survey selected by self-report or claims-based diagnoses of diabetes in year 1 and use of statins in year 2 (N = 899). We computed the number of 30-day statin prescription fills, out-of-pocket and third-party drug costs, and Medicare Part A and Part B spending. Multivariate ordinary least squares regression models predicted statin fills as a function of out-of-pocket costs, and a generalized linear model with log link predicted Medicare spending as a function of number of fills, controlling for baseline characteristics. Estimated coefficients were used to simulate changes in fills associated with co-payment caps from $25 to $1 and to compute changes in third-party payments and Medicare cost offsets associated with incremental fills. Analyses were stratified by patient cardiovascular event risk. A simulated out-of-pocket price of $25 [$1] increased plan drug spending by $340 [$794] and generated Medicare Part A/B savings of $262 [$531]; savings for high-risk patients were $558 [$1193], generating a net saving of $249 [$415]. Reducing statin co-payments for Medicare beneficiaries with diabetes resulted in modestly increased use and reduced medical spending. The value-based insurance design simulation strategy met financial feasibility criteria but only for higher-risk patients.
  Value in Health 05/2012; 15(3):404-11. · 2.19 Impact Factor
• Article: Eligibility and take-up of the Medicare Part D low-income subsidy.

  J Samantha Shoemaker, Amy J Davidoff, Bruce Stuart, Ilene H Zuckerman, Eberechukwu Onukwugha, Christopher Powers
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  ABSTRACT: There is concern about poor take-up of the Medicare Part D Low-Income Subsidy (LIS), but uncertainty in published estimates. The Medicare Current Beneficiary Survey (MCBS), which contains Medicare LIS enrollment records and extensive survey data on individual beneficiary characteristics, would appear an ideal resource for evaluating LIS take-up. However, use of the MCBS to identify eligible beneficiaries is limited due to underreporting of income and lack of asset information in the published MCBS releases. We evaluate LIS eligibility and participation by enhancing the reliability of MCBS financial information using unpublished survey data on income and assets together with an income imputation procedure.
  Inquiry: a journal of medical care organization, provision and financing 01/2012; 49(3):214-30. · 0.83 Impact Factor
• Article: Does medication adherence lower Medicare spending among beneficiaries with diabetes?

  Bruce Stuart, Amy Davidoff, Ruth Lopert, Thomas Shaffer, J Samantha Shoemaker, Jennifer Lloyd
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  ABSTRACT: To measure 3-year medication possession ratios (MPRs) for renin-angiotensin-aldosterone system (RAAS) inhibitors and statins for Medicare beneficiaries with diabetes, and to assess whether better adherence is associated with lower spending on traditional Medicare services controlling for biases common to previous adherence studies. Medicare Current Beneficiary Survey data from 1997 to 2005. Longitudinal study of RAAS-inhibitor and statin utilization over 3 years. The relationship between MPR and Medicare costs was tested in multivariate models with extensive behavioral variables to control for indication bias and healthy adherer bias. Over 3 years, median MPR values were 0.88 for RAAS-I users and 0.77 for statin users. Higher adherence was strongly associated with lower Medicare spending in the multivariate analysis. A 10 percentage point increase in statin MPR was associated with U.S.$832 lower Medicare spending (SE=219; p<.01). A 10 percentage point increase in MPR for RAAS-Is was associated with U.S.$285 lower Medicare costs (SE=114; p<.05). Higher adherence with RAAS-Is and statins by Medicare beneficiaries with diabetes results in lower cumulative Medicare spending over 3 years. At the margin, Medicare savings exceed the cost of the drugs.
  Health Services Research 03/2011; 46(4):1180-99. · 2.16 Impact Factor
• Source

  Available from: Ruth Lopert

  Article: Does Medication Adherence Lower Medicare Spending among Beneficiaries with Diabetes?

  Bruce Stuart, Amy Davidoff, Ruth Lopert, Thomas Shaffer, J Samantha Shoemaker, Jennifer Lloyd
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  ABSTRACT: Objective. To measure 3-year medication possession ratios (MPRs) for renin– angiotensin–aldosterone system (RAAS) inhibitors and statins for Medicare benefi-ciaries with diabetes, and to assess whether better adherence is associated with lower spending on traditional Medicare services controlling for biases common to previous adherence studies. Data Source. Medicare Current Beneficiary Survey data from 1997 to 2005. Study Design. Longitudinal study of RAAS-inhibitor and statin utilization over 3 years. Data Collection. The relationship between MPR and Medicare costs was tested in multivariate models with extensive behavioral variables to control for indication bias and healthy adherer bias. Principal Findings. Over 3 years, median MPR values were 0.88 for RAAS-I users and 0.77 for statin users. Higher adherence was strongly associated with lower Medicare spending in the multivariate analysis. A 10 percentage point increase in statin MPR was associated with U.S.$832 lower Medicare spending (SE 5 219; po.01). A 10 percentage point increase in MPR for RAAS-Is was associated with U.S.$285 lower Medicare costs (SE 5 114; po.05). Conclusions. Higher adherence with RAAS-Is and statins by Medicare beneficiaries with diabetes results in lower cumulative Medicare spending over 3 years. At the mar-gin, Medicare savings exceed the cost of the drugs. Clinical trials have established that statins and renin–angiotensin–aldosterone system (RAAS) inhibitors, including angiotensin-converting enzyme (ACE)-inhibitors and angiotensin II receptor blockers, can provide benefits for many elderly diabetic patients by preventing or delaying certain secondary com-plications of the disease (Brown et al. 2003; Odegard and Capoccia 2007; American Diabetes Association 2008). Indeed, the evidence has convinced some clinicians that virtually all elderly diabetics should be treated with ACE-inhibitors (Birkmeyer and Welch 2005; Rosen et al. 2005) and statins r Health Research and Educational Trust
  Health Services Research 01/2011; · 2.16 Impact Factor
• Article: Lessons learned: who didn't enroll in Medicare drug coverage in 2006, and why?

  Amy J Davidoff, Bruce Stuart, Thomas Shaffer, J Samantha Shoemaker, Melissa Kim, Christopher Zacker
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  ABSTRACT: The law that created Medicare's prescription drug benefit, Medicare Part D, also established extra help for low-income seniors in the form of a subsidy. This study, the first in-depth analysis of Part D enrollment among Medicare beneficiaries without prior drug coverage, finds that 63 percent of all eligible seniors and 69 percent of low-income beneficiaries were enrolled in Part D in 2006. However, only 29 percent of low-income beneficiaries were enrolled in the subsidy program, leaving millions without coverage. Many reported that premiums were too costly, enrollment too difficult, and information too hard to obtain for enrollment. Additionally, provisions of the recently enacted Patient Protection and Affordable Care Act may have the perverse impact of reducing enrollment in Part D for certain beneficiaries. Our findings emphasize the need to expand eligibility and improve policies to foster enrollment.
  Health Affairs 06/2010; 29(6):1255-63. · 4.31 Impact Factor
• Article: Does influenza vaccination of older adult Medicare beneficiaries lower treatment costs for acute and chronic respiratory disease?

  Bruce Stuart, Amy Davidoff, Jennifer Lloyd, Thomas Shaffer, J Samantha Shoemaker, Jason Kemner
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  ABSTRACT: Influenza accounts for a large proportion of hospitalizations and deaths among older adults, resulting in substantial health care expenses. Influenza vaccinations are effective in reducing respiratory infections in younger populations, but it is less certain whether they reduce costs associated with respiratory infections among older adults. The purpose of this study was to determine whether influenza vaccination of older adult Medicare beneficiaries reduced costs associated with acute and chronic respiratory conditions during 3 recent influenza seasons. This study analyzed the relationship between influenza vaccination and costs for respiratory conditions among Medicare beneficiaries >or=55 years of age in influenza seasons (October-May) between 2002 and 2005 using data from the Medicare Current Beneficiary Survey. Two-part multiple regressions of vaccination status were estimated on the probability and cost of treating respiratory conditions in each influenza season controlling for influenza risk factors and other covariates. Various sensitivity tests were conducted by type of service, subgroup analysis for specific population risk segments, propensity score-matched comparisons, and difference equations. The study sample included 13,402 Medicare beneficiaries for the 3 influenza seasons examined. Vaccination rates varied between 67.3% and 74.9% over the 3 influenza seasons. In unadjusted comparisons, no significant difference in the cost of treating respiratory conditions was found between vaccinated and unvaccinated beneficiaries in 2002/2003 (-$104), but vaccinated beneficiaries had significantly higher mean cost differentials in the more recent influenza seasons ($258 in 2003/2004, P = 0.012; $254 in 2004/2005, P = 0.003). Based on 2-part multiple regressions of vaccine status over the 3 seasons combined, costs of respiratory conditions were $142 dollars higher on average for vaccinated beneficiaries (P = 0.014). The base regression models showed no significant cost savings from vaccination in any year. Results of 2 of the 54 sensitivity tests that were conducted indicated significant savings from vaccination (inpatient costs for 2002/2003 and difference in total costs for persons unvaccinated in 2002/2003 but vaccinated in 2003/2004). In this study of older adults, no significant cost savings were found with influenza vaccines in the 3 influenza seasons examined (2002-2005) when the outcome was measured in terms of differential spending for acute and chronic respiratory conditions.
  The American journal of geriatric pharmacotherapy. 06/2010; 8(3):201-14.