Medicare Part D low-income subsidies expanded in January 2024, but more needs to be done to ensure that eligible beneficiaries enroll.

BACKGROUND: The Inflation Reduction Act of 2022 extended full low-income subsidies (LIS) to a small group of Medicare Part D recipients with limited assets and incomes between 135% and 150% of the Federal Poverty Level beginning in January 2024. This policy may result in small enrollment gains among beneficiaries eligible for the new benefits, but the biggest problem with the current LIS program is underenrollment across all eligibility groups. Prior research has shown that underenrollment has been a persistent problem since the LIS program began in 2006, yet little has been done to correct the situation. OBJECTIVE: To identify individual-level factors associated with failure to enroll among low-income beneficiaries eligible for both full subsidies and partial subsidies under the LIS program. METHODS: We used 2019 Medicare Current Beneficiary Survey data for the study. The Medicare Current Beneficiary Survey is uniquely suited for this work because it contains administrative data on LIS enrollment plus extensive survey information on financial resources necessary to establish program eligibility. We conducted descriptive and multivariate analyses to identify factors associated with failure to enroll when eligible for either full or partial subsidies. Explanatory variables included sociodemographic characteristics, economic resources, work status, health variables, and source of prescription coverage (for nonsubsidized beneficiaries). RESULTS: In 2019, 73% of beneficiaries eligible for full subsidies under pre-Inflation Reduction Act LIS provisions were enrolled, compared with only 25% eligible for partial subsidies. The number of those estimated to be eligible for full subsidies but not enrolled (N = 3.9 million) was more than double that of those eligible but not enrolled for partial subsidies (N = 1.5 million). Factors associated with failure to enroll (older age, male sex, White race, married, higher education, higher income and assets, and excellent/very good health status) were similar for both groups. In multivariate analyses, the single strongest predictor of failure to enroll was receipt of income from work (odds ratio = 5.50; P < 0.001). Among the nonenrolled, 64% eligible for full subsidies and 75% eligible for partial subsidies maintained unsubsidized Part D coverage. CONCLUSIONS: Significant numbers of low-income Medicare beneficiaries are eligible for Part D subsidies but fail to enroll. Common characteristics distinguishing nonenrollees from enrollees include older age with higher proportions of White individuals, married individuals, higher income and assets, and better overall health. Two promising targets for increasing LIS enrollment are evidence of work income and unsubsidized Part D coverage.

Can one or two simple questions predict poor medication adherence?

RATIONALE, AIMS, AND OBJECTIVES: Poor adherence to evidence-based medications is a major problem in conventional clinical practise. Better prognostic tools are needed to identify those with the highest likelihood of being non-adherent. The objective of this study is to determine if a 2-item patient activation status (PAS) measure identifies Medicare beneficiaries at risk of poor adherence to drugs typically recommended in treating type 2 diabetes. METHODS: PAS and medication adherence were assessed for respondents to the 2009 Medicare Current Beneficiary Survey and then compared using bivariate and multivariate tests. Participants' PAS was classified as "active," "high effort," "complacent," or "passive" based on how confident they were in identifying needed medical care and whether they brought medication lists to their doctors' visits. Adherence with oral antidiabetic drugs, angiotensin-converting enzyme-inhibitors/angiotensin receptor blockers, and statins was assessed using proportion of days covered (PDC). RESULTS: A total of 940 Medicare beneficiaries with diabetes enrolled in Part D plans in 2009. The overall effect of PAS on medication adherence was small (3% lower PDC for complacent/passive vs active/high effort beneficiaries, P < 0.10). However, interactions of complacent/passive PAS with other characteristics associated with poor adherence identified certain subgroups as especially prone to problematic adherence: age < 65 (PDC -11%, P < 0.05), non-Hispanic black (PDC -13%, P < 0.05), and morbidly obese (-9%, P < 0.10). CONCLUSION: A single question relating to taking medication lists to doctor visits may help identify patient subgroups prone to poor adherence in conventional practise, but larger samples are necessary to validate and extend these findings.

Placement of selected new FDA-approved drugs in Medicare Part D formularies, 2009-2013.

OBJECTIVES: To assess formulary decisions by Part D plans for selected newly approved drugs. STUDY DESIGN: Retrospective cohort study. METHODS: Formulary placement and restrictions were identified for 33 drugs in 8 therapeutic classes (antihyperglycemics, anticoagulants, antiplatelets, disease-modifying agents for multiple sclerosis [MS] and rheumatoid arthritis [RA], chronic obstructive pulmonary disease [COPD] drugs, antiepileptics, and antipsychotics) in 863 Part D plans with continuous CMS contracts between 2009 and 2013. Multivariable models estimated the impact of drug characteristics and Part D plan characteristics on probability of drug adoption and, for adopters, evaluated factors associated with months to adoption and requirements for prior authorization (PA) or step therapy (ST). RESULTS: First Part D formulary placements varied from 2 to 14 months post FDA approval. On average, 56.7% of plans placed each drug within 6 months and 64.1% placed within 1 year of the National Drug Code assignment date. The most rapid adoption was for antipsychotics and antiepileptics. The slowest was for COPD drugs. More than 90% of disease-modifying agents for MS and RA were subject to PA. ST was uncommon except for antihyperglycemic agents. In adjusted analyses, enhanced benefit plans had a 4% higher probability of formulary placement (P <.01), and each additional star in the CMS star rating system increased the probability of adoption by 4% (P <.01). Overall, Medicare Advantage prescription drug plans had higher placement rates due to greater reliance on enhanced plan offerings and higher star ratings. CONCLUSIONS: We found significant heterogeneity in formulary placement and restrictions for 33 new drugs in the Part D marketplace between 2009 and 2013. Further research is necessary to determine whether this pattern applies to other drug classes.

Impact of formulary restrictions on medication intensification in diabetes treatment.

OBJECTIVES: To explore formulary restrictions on noninsulin antihyperglycemic drugs (NIADs) in Medicare Part D plans and to estimate the impact of formulary restrictions on use of NIADs among low-income subsidy (LIS) recipient enrollees with type 2 diabetes (T2D) undergoing treatment intensification. STUDY DESIGN: Retrospective cohort study. METHODS: A cohort of 2919 LIS enrollees with T2D receiving metformin monotherapy during the first quarter of 2012 who intensified treatment later in the year was tracked to assess selection of and days' supply with sulfonylureas, dipeptidyl peptidase-4 (DPP-4) inhibitors, and other NIADs. We tested whether being enrolled in a Part D plan with significant formulary restrictions on sole-source brand name NIADs reduced the likelihood of receiving such agents and, if so, what the impact was on days of therapy with the second agent. A 2-part regression model was estimated with explanatory variables for plan-level restrictions and individual covariates. RESULTS: We found that 63% of study subjects initiated a sulfonylurea, 25% a DPP-4 inhibitor, and 12% another NIAD. Greater restrictions on DPP-4 inhibitors as a class were associated with small reductions in initiation of DPP-4 inhibitors and a concomitant increase in use of sulfonylureas, but neither effect was statistically significant. For individual DPP-4 inhibitors, step therapy requirements on sitagliptin and formulary exclusion of saxagliptin resulted in significant reductions in uptake of the specific drugs but had no significant impact on total days' supply of antihyperglycemic therapy. CONCLUSIONS: Part D formulary restrictions on sole-source brand name NIADs had little impact on patterns of treatment intensification for T2D among LIS recipients enrolled in Medicare Part D plans in 2012.

Impact of formulary restrictions on medication use and costs.

OBJECTIVES: To evaluate the effects of formulary restrictions on utilization and costs of oral hypoglycemic agents (OHAs), statins, and renin-angiotensin system (RAS) antagonists among low-income subsidy (LIS) recipients in Medicare Part D plans. STUDY DESIGN: We analyzed a 5% sample of 2012 Medicare data from the Chronic Conditions Data Warehouse together with a customized dataset capturing beneficiaries' histories of plan assignment. METHODS: We constructed 3 nonexclusive study cohorts comprising of users of OHAs, statins, and RAS antagonists. Eligible study subjects were LIS recipients randomized to benchmark plans. Formulary restrictions of interest were noncoverage, prior authorization, and step therapy. Study outcomes included generic dispensing rate (GDR), mean cost per prescription fill, and medication adherence based on proportion of days covered (PDC). Random intercept regression models were performed to estimate the effects of formulary restrictions on the study outcomes by drug class. RESULTS: After covariate adjustment, beneficiaries who were subject to formulary restrictions on brand name pioglitazone and single-source brand name dipeptidyl peptidase-4 inhibitors (saxagliptin, sitagliptin, and sitagliptin-metformin) had a GDR 3 percentage points higher and a cost per prescription fill $10.8 less, but similar PDC compared with those who faced no restrictions. Restricting access to brand name atorvastatin and single-source brand name statins (rosuvastatin and ezetimibe-simvastatin) was associated with a GDR 14.9 percentage points higher and a cost per prescription fill $29.6 less, but with no impact on PDC. Restricting use of single-source brand name RAS antagonists (olmesartan, valsartan, and valsartan-hydrochlorothiazide) was associated with a GDR 15.0 percentage points higher, a cost per prescription fill $27.2 less, and a PDC 1.3 percentage points lower. CONCLUSIONS: Placing formulary restrictions on brand name drugs shifts utilization toward generic drugs, lowers the overall cost per prescription fill, and has minimal impact on overall adherence for OHAs, statins, and RAS antagonists among LIS recipients.

Proximal Predictors of Long-Term Discontinuance with Noninsulin Antihyperglycemic Agents.

BACKGROUND: Noninsulin antihyperglycemic agents (NAAs) are the mainstay of treatment for type 2 diabetes, yet persistence in NAA use is suboptimal in many diabetes patients. Most of the research on NAA discontinuance has focused on sociodemographic characteristics and general health status, but such factors are inherently limited in explaining dynamic events such as discontinuance. OBJECTIVE: To assess the relative importance of static and proximal dynamic factors in explaining long-term NAA discontinuance among Medicare beneficiaries with diabetes. METHODS: Two sets of probability models were estimated to predict NAA discontinuance as a function of static variables (age, sex, race, original reason for Medicare entitlement, low-income subsidy and dual Medicare/Medicaid eligibility status, and disease burden) and 21 dynamic factors capturing month-by-month changes in drug use, health status, and use of medical services leading up to discontinuance (defined as month 0) and the previous 4 months (designated months -1 to -4) among 71,619 patients with diabetes enrolled in Medicare Part D plans in 2006-2008. RESULTS: Static variables explained just 1.2% of the variance in probability of NAA discontinuance compared with 14% for all variables combined. Key time-related predictors of NAA discontinuance included discontinuation with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs) and statins, hypoglycemia, NAA usage gaps, insulin use, and discharge from hospitals and skilled nursing facilities (SNFs). The strongest significant predictors (P < 0.05) of NAA discontinuance were discontinuation with statins and ACEIs/ARBs in month 0 (predicted probabilities of 37% and 34%, respectively). Other variables that significantly increased the probability of NAA discontinuance by 10% or more were hypoglycemia in month 0 (14%) and month -1 (17%), discontinuance with ACEIs/ARBs in months -1 (15%) and -2 (10%), discontinuance with statins in month -1 (13%), and insulin use in month 0 (12%). Experiencing a previous gap in NAA therapy was associated with higher likelihood of discontinuance if the gap occurred in month -2 (10%) or month -4 (6%), but a gap in therapy in month -1 actually reduced the likelihood of discontinuance by 13%. Discharge from a hospital or SNF was consistently associated with higher probabilities of NAA discontinuance ranging between 4% and 10%, with higher probabilities occurring closer to month 0. CONCLUSIONS: A cascade of dynamic changes preceding discontinuance with NAA therapy among Medicare Part D enrollees with diabetes was observed between 2006 and 2008. Understanding that lack of persistence in drug use is a dynamic rather than a static phenomenon opens up new avenues for investigating and ultimately improving adherence behavior in the elderly. DISCLOSURES: This study was funded by Merck & Co. Huang and Raipathak are employees of Merck & Co. Brandt reports consultancy and speaker fees from Catapult, Omnicare, RAND, HRSA, CMS, and AGS Beers Criteria. Loh is currently employed at Touro College of Pharmacy. All other authors have no relevant potential conflicts of interest to disclose. Study concept and design were primarily contributed by Stuart, Quinn, and Brandt, along with Shen, Roberto, Hendrick, Huang, and Rajpathak. Shen, Loh, Hendrick, and Kim collected the data, and data interpretation was performed primarily by Stuart, Shen, and Roberto, assisted by Quinn, Brandt, Hendrick, Huang, and Rajpathak. The manuscript was written primarily by Stuart, with assistance from the other authors, and revised by Huang, Rajpathak, and Stuart, with assistance from the other authors.

Changes in Medication Management After a Diagnosis of Cancer Among Medicare Beneficiaries With Diabetes.

PURPOSE: A new cancer diagnosis commonly initiates a cascade of health care decisions that have potentially important consequences for management of other chronic conditions such as diabetes. We sought to determine whether a new cancer diagnosis is associated with changes in medication adherence among Medicare beneficiaries with diabetes, and whether the relationship is affected by life expectancy and generosity of drug coverage. METHODS: The study population was drawn from a 5% random sample of Medicare beneficiaries with diabetes enrolled in Medicare Part D in 2007 and 2008. Patients had cancer newly diagnosed between January and December 2007 (n = 4,348) and were compared with a cancer-free control group (N = 28,507) assigned a pseudo-diagnosis date. Adherence (proportion of days covered [PDC]) with oral hypoglycemic agents, renin-angiotensin-aldosterone system inhibitors, and statins was tracked for 6 months before and after the diagnosis date. Multivariable regression models assessed the independent impact of a cancer diagnosis, life expectancy (proxy measure: died 7 to 12 months after index date), and coverage generosity (proxy measure: low-income subsidy recipient) on PDC, controlling for individual characteristics. RESULTS: Relatively larger declines in medication adherence (3 to 5 percentage points; P < .001) were observed overall for patients with cancer versus controls. Short life expectancy was associated with between 8% and 11% lower PDC (P < .001) in the cancer subgroup relative to controls. Low-income subsidy status had no differential effect on changes in drug adherence. CONCLUSION: A cancer diagnosis among patients with diabetes reduced adherence with evidence-based medications, particularly if patients' life expectancy was short.

Does good medication adherence really save payers money?

BACKGROUND: Despite a growing consensus that better adherence with evidence-based medications can save payers money, assertions of cost offsets may be incomplete if they fail to consider additional drug costs and/or are biased by healthy adherer behaviors unobserved in typical medical claims-based analyses. OBJECTIVES: The objective of this study was to determine whether controlling for healthy adherer bias (HAB) materially affected estimated medical cost offsets and additional drug spending associated with higher adherence. SUBJECTS: A total of 1273 Medicare beneficiaries with diabetes enrolled in Part D plans between 2006 and 2009. RESEARCH DESIGN: Using survey and claims data from the Medicare Current Beneficiary Survey, we measured medical and drug costs associated with good and poor adherence (proportion of days covered ≥ 80% and <80%, respectively) to oral antidiabetic drugs, ACE inhibitors/ARBs, and statins over 2 years. To test for HAB, we estimated pairs of regression models, one set containing variables typically controlled for in conventional claims analysis and a second set with survey-based variables selected to capture HAB effects. RESULTS: We found consistent evidence that controlling for HAB reduces estimated savings in medical costs from better adherence, and likewise, reduces estimates of additional adherence-related drug spending. For ACE inhibitors/ARBs we estimate that controlling for HAB reduced adherence-related medical cost offsets from $6389 to $4920 per person (P<0.05). Estimates of additional adherence-related drug costs were 26% and 14% lower in HAB-controlled models (P < 0.05). CONCLUSIONS: These results buttress the economic case for action by health care payers to improve medication adherence among insured persons with chronic disease. However, given the limitations of our research design, further research on larger samples with other disease states is clearly warranted.

Patient cost sharing and receipt of erythropoiesis-stimulating agents through medicare part D.

PURPOSE: Medicare Part D prescription benefits cover injected medications, normally covered under Part B, when administered outside of physician offices. Erythropoiesis-stimulating agents (ESAs) used for chronic anemia management in patients with myelodysplastic syndromes (MDS) are commonly injected in a physician office but can be administered safely at home. In this study, we explored out-of-pocket (OOP) costs and receipt of Part D-covered ESAs in Medicare beneficiaries with MDS. MATERIALS AND METHODS: Patients with MDS enrolled in Medicare Parts A, B, and D were identified using diagnosis codes from 100% claims from 2006 to 2008. OOP costs for the mean erythropoietin alfa claim were compared for Parts B and D. Multivariable models examined the effect of low-income subsidy (LIS) and other Part D cost sharing on receipt of any ESA and any Part D-covered ESA. RESULTS: A total of 13,117 (62.9%) of 20,848 patients received ESAs, but only 1,436 (6.9%) had any Part D claim. OOP payment was $348 under Part D versus $161 under Part B. Among patients with ESA use, those with LIS were 4× more likely to receive Part D ESAs (P < .01). CONCLUSION: Few patients with MDS received ESAs through Part D. OOP payments required under Part D were substantially higher than under Part B. Cost sharing, as reflected by LIS receipt, likely affected decisions to prescribe ESAs outside of the physician office. Improved coordination between Part B and D benefits regarding issues of home injection of medications may create incentives that improve patient access and convenience and reduce costs associated with administration.

Use and spending on antineoplastic therapy for Medicare beneficiaries with cancer.

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.

Impact of maintenance therapy on hospitalization and expenditures for Medicare beneficiaries with chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is associated with high levels of hospitalization and health care expenditures among the aged. Adherence to appropriate maintenance drug regimens has been reported to reduce hospitalization and health care spending in clinical trials. However, little research has been conducted to compare use versus nonuse of these medications in terms of health-related outcomes in routine practice. OBJECTIVE: The purpose of this study was to compare differences between users and nonusers of maintenance medications in terms of selected outcomes for a nationally representative sample of Medicare beneficiaries with COPD. METHODS: The study sample was selected from Medicare Current Beneficiary Surveys conducted between 1997 and 2005. Beneficiaries with COPD who used ≥1 maintenance medication annually were compared with nonusers on 3 claims-based outcomes: any hospitalization, any rehospitalization within 31 days, and total annual Medicare expenditures. RESULTS: The study sample consisted of 6322 Medicare beneficiaries who contributed a total of 9161 person-year observations for analysis. Over the 9-year study period, 39.9% (3659/9161) of the person-year observations were recorded for maintenance medication users, and 60.1% (5502/9161) were recorded for nonusers. Most of the observations for medication users involved beneficiaries who were female (50.1% [1833/3659]), non-Hispanic white (85.4% [3124/3659]), and ≥65 years of age (88.2% [3228/3659]); most of the observations for nonusers involved beneficiaries who were male (51.9% [2855/5502]), non-Hispanic white (82.7% [4550/5502]), and ≥65 years of age (88.1% [4848/5502]). Annually, 40% of the sample filled prescriptions for COPD maintenance medications. In multivariate models, maintenance drug users were less likely than nonusers to be hospitalized (odds ratio [OR] = 0.70; 95% CI, 0.61 to 0.79) or rehospitalized (OR= 0.74; 95% CI, 0.63 to 0.87), and had significantly lower annual Medicare expenditures (-$3916; 95% CI, -$4977 to -$2854). CONCLUSIONS: In this comparison of users and nonusers of maintenance medication for COPD, use of maintenance therapy was associated with significantly lower risks of hospitalization and rehospitalization and reduced Medicare expenditures.

Increased persistency in medication use by U.S. Medicare beneficiaries with diabetes is associated with lower hospitalization rates and cost savings.

OBJECTIVE: To assess the relationship between annual fills for antidiabetes medications, ACE inhibitors, angiotensin II receptor blockers (ARBs), and lipid-lowering agents on hospitalization and Medicare spending for beneficiaries with diabetes. RESEARCH DESIGN AND METHODS: Using Medicare Current Beneficiary Survey data from 1997 to 2004, we identified 7,441 community-dwelling beneficiaries with diabetes, who contributed 14,317 person-years of data for the analysis. We used multivariate regression analysis to estimate the effect of persistency in medication fills on hospitalization risk, hospital days, and Medicare spending. RESULTS: For users of older oral antidiabetes agents, ACE inhibitors, ARBs, and statins, each additional prescription fill was associated with significantly lower risk of hospitalization, fewer hospital days, and lower Medicare spending. CONCLUSIONS: These results suggest an economic case for promoting greater persistency in use of drugs with approved indications by Medicare beneficiaries with diabetes; however, additional research is needed to corroborate the study's cross-sectional findings.

Assessing the impact of drug use on hospital costs.

OBJECTIVE: To assess whether outpatient prescription drug utilization produces offsets in the cost of hospitalization for Medicare beneficiaries. DATA SOURCES/STUDY SETTING: The study analyzed a sample (N=3,101) of community-dwelling fee-for-service U.S. Medicare beneficiaries drawn from the 1999 and 2000 Medicare Current Beneficiary Surveys. STUDY DESIGN: Using a two-part model specification, we regressed any hospital admission (part 1: probit) and hospital spending by those with one or more admissions (part 2: nonlinear least squares regression) on drug use in a standard model with strong covariate controls and a residual inclusion instrumental variable (IV) model using an exogenous measure of drug coverage as the instrument. PRINCIPAL FINDINGS: The covariate control model predicted that each additional prescription drug used (mean=30) raised hospital spending by $16 (p<.001). The residual inclusion IV model prediction was that each additional prescription fill reduced hospital spending by $104 (p<.001). CONCLUSIONS: The findings indicate that drug use is associated with cost offsets in hospitalization among Medicare beneficiaries, once omitted variable bias is corrected using an IV technique appropriate for nonlinear applications.

How disease burden influences medication patterns for Medicare beneficiaries: implications for policy.

This issue brief provides benchmarks, based on empirical analyses of 2002 data, for evaluating the quality of pharmaceutical care under the Medicare Part D prescription drug benefit. The analyses cover all major classes of pharmaceuticals used by beneficiaries with one of eight chronic conditions. Common patterns observed include: 1) a mounting disease burden is associated with increasingly complex medication regimens in every group, and 2) the intensity and persistence of drug use tend to rise with disease burden up to a point, before declining for beneficiaries with the greatest morbidity. The study concludes that neither traditional drug quality indicators nor new quality assurance mechanisms mandated by law are well aligned to capture suboptimal medication use at either end of the spectrum of disease burden in the Medicare population. A holistic approach to medication management is needed to ensure that Part D plans meet beneficiaries and policymakers' expectations for high-quality care.

Estimating the effects of prescription drug coverage for Medicare beneficiaries.

OBJECTIVE: To identify the effect of insurance coverage on prescription utilization by Medicare beneficiaries. DATA SOURCES/STUDY SETTING: Secondary data from the 1999 Medicare Current Beneficiary Survey (MCBS) Cost and Use files, a nationally representative survey of Medicare enrollees. STUDY DESIGN: The paper uses a cross-sectional design with (1) a standard regression framework to estimate the impact of prescription coverage on utilization controlling for potential selection bias with covariate control based on the Diagnostic Cost Group/Hierarchical Condition Category (DCG/HCC) risk adjuster, and (2) a multistage residual inclusion method using instrumental variables to control for selection bias and identify the insurance coverage effect. DATA COLLECTION/EXTRACTION METHODS: Data were extracted from the 1999 MCBS. Study inclusion criteria are community-dwelling MCBS respondents with full-year Medicare enrollment and supplemental medical insurance with or without full-year drug benefits. The final sample totaled 5,270 Medicare beneficiaries. PRINCIPAL FINDINGS: Both the model using the DCG/HCC risk adjuster and the model using the residual inclusion method produced similar results. The estimated price elasticity of demand for prescription drugs for the Medicare beneficiaries in our sample was -0.54. CONCLUSIONS: Our results confirm that selection into prescription coverage is predictable based on observable health. Our results further confirm prior estimates of price sensitivity of prescription drug demand for Medicare beneficiaries, though our estimate is slightly above prior results.

Propoxyphene use and risk for hip fractures in older adults.

BACKGROUND: Published guidelines have identified propoxyphene as an inappropriate medication for use in aged patients. It is no more effective than acetaminophen, yet has been associated with the same adverse effects (AEs) associated with other opioid drugs. In particular, its central nervous system-related AEs, dizziness and sedation, may increase the risk for fracture resulting from falls in older adults. Nonetheless, US studies have reported widespread use of propoxyphene in the elderly US population. OBJECTIVE: The aim of this study was to examine the risk for fracture associated with propoxyphene use in older adults. METHODS: This prospective cohort study used a large administrative claims data set from adults aged > or =65 years. A time-varying (lagged) covariate defined each person as a propoxyphene user or nonuser based on propoxyphene exposure in the 14 days before each fracture event in the cohort. Another time-varying measure stratified propoxyphene users based on their mean daily dose of propoxyphene (high dose = >260 mg; low dose = < or =260 mg of propoxyphene hydrochloride or equivalent napsylate salt). Time-dependent Cox regression models were used to estimate the association between propoxyphene exposure and occurrence of hip fracture (using International Classification of Diseases, Ninth Revision, Clinical Modification code 820.xx). RESULTS: A total of 362,503 patients were included in the analysis. During a mean follow-up of 464 days, approximately 10% (37,569) of the sample had > or =1 propoxyphene prescription filled and approximately l% (5065) sustained a hip fracture. Propoxyphene users had a 2-fold higher risk for hip fracture (hazard ratio [HR] [95% CI], 2.05 [1.87-2.25]) compared with nonusers of analgesics. Multivariate analysis found a dose-response relationship between propoxyphene and hip fracture risk (low dose, HR [95% CI], 1.45 [1.26-1.67]; high dose, HR [95% CI], 2.05 [1.85-2.29]). Other opioid analgesics were associated with an increased risk for hip fractures. CONCLUSIONS: The results of this cohort database study suggest that propoxyphene use among adults aged > or =65 years is associated with increased risk for hip fracture and suggest a need for interventions to reduce propoxyphene use in older adults. Clinicians should be aware of the risk for hip fracture with other opioids as well and weigh them against potential benefits when prescribing for older adults.

Over-the-counter drug use by medicare beneficiaries in nursing homes: implications for practice and policy.

OBJECTIVES: To examine over-the-counter (OTC) medication use by Medicare beneficiaries in nursing homes and to assess evidence of substitution of OTC medications for prescription (Rx) medications by residents with no Rx coverage and Medicaid. DESIGN: Cross-sectional multivariable analysis. SETTING: Medicare beneficiaries included in the nationally representative Medicare Current Beneficiary Survey in 2001. PARTICIPANTS: Seven hundred eighty-nine Medicare beneficiaries with 1 or more months in a nursing home. MEASUREMENTS: Proportions of residents using Rx and OTC medications per resident-month and counts of drugs used within selected therapeutic classes. RESULTS: Study subjects were high users of Rx (98%) and OTC (94%) drugs. The average resident was administered 8.8 unique medications per month (5.9 Rx and 2.9 OTC medications). Twelve therapeutic classes accounted for 93.9% of OTC medication use by residents, but Rx use was also high in some of these same classes. For example, 70.3% of all subjects used nonopioid OTC analgesics, and 19.0% used nonopioid Rx analgesics, and 13.8% used OTC antacids/antiulcer agents, whereas 35.8% used Rx products in this class. The highest overlap was in the category of cough and cold medications, of which 19.3% used OTCs and 20.1% used Rx drugs. Multivariate regression analyses applied to users of drugs in each these three therapeutic classes found no evidence that Rx coverage influenced the choice of OTC versus Rx-only medications. CONCLUSION: OTCs represent an important component of the therapeutic regimens of nursing home residents, but utilization rates are insensitive to drug coverage. That may change with the implementation of the Medicare Part D drug benefit.

National trends in and predictors of propoxyphene use in community-dwelling older adults.

BACKGROUND: Several pain management guidelines and explicit medication-use criteria identify propoxyphene as an inappropriate medication for use in older adults. OBJECTIVE: This study was conducted to estimate trends in propoxyphene use among community-dwelling elderly (age > or = 65 years) Medicare beneficiaries from 1993 through 1999 and to determine whether beneficiaries' drug coverage and specific characteristics of their physicians were associated with receipt of propoxyphene in 1999. METHODS: Data from the Medicare Current Beneficiary Survey (MCBS) were used to examine the prevalence of propoxyphene use in cross-sections of nationally representative samples of community-dwelling elderly Medicare beneficiaries from 1993 through 1999. The 1999 MCBS was linked with the 1999 Area Resource File to examine patient and physician factors associated with propoxyphene use in the community-dwelling elderly at the county level. RESULTS: Rates of propoxyphene use were generally stable over the 7-year period, from an annual prevalence of 6.8% in 1993 to the slightly decreased prevalence of 6.6% in 1999. No protective effects against propoxyphene use were observed based on beneficiaries' drug coverage or type of drug coverage. Rather, Medicaid beneficiaries were more likely to receive propoxyphene than those without drug coverage (odds ratio [OR] = 1.40; 95% CI, 1.02-1.92). Among physician characteristics, male sex (OR = 1.34; 95% CI, 1.02-1.75) and medical specialty (OR = 0.81; 95% CI, 0.65-1.00) were strongly correlated with prescribing of propoxyphene. CONCLUSION: This study found a continuing high prevalence of propoxyphene use in the community-dwelling elderly Medicare population from 1993 through 1999, with > 2 million beneficiaries receiving the drug in 1999.

Propoxyphene use by community-dwelling and institutionalized elderly Medicare beneficiaries.

OBJECTIVES: To provide the first comparable national prevalence estimates on use of propoxyphene, a potentially inappropriate drug, by elderly Medicare beneficiaries living in the community and institutions and to determine whether institutionalized beneficiaries are at a greater risk for receiving propoxyphene than community-dwelling beneficiaries. DESIGN: Cross-sectional study. SETTING: U.S. representative sample of elderly using Medicare database. PARTICIPANTS: Nationally representative sample of community-dwelling (n = 9,851, weighted n = 32.5 million) and institutionalized (n = 1,099, weighted n = 2.3 million) Medicare beneficiaries aged 65 and older. MEASUREMENTS: National estimates on prevalence of propoxyphene use and the odds of receiving propoxyphene were the two main outcome measures. RESULTS: Annual prevalence of propoxyphene use in 1998 was 6.8% by all community-dwelling elderly beneficiaries and 15.5% by institutionalized elderly beneficiaries. Beneficiaries in long-term care facilities had almost 40% higher odds of receiving propoxyphene (odds ratio = 1.38, 95% confidence interval = 1.1-1.8) than beneficiaries in the community even after controlling for other factors in a logistic regression. Other risk factors include female, rural residence, poor health, and history of osteoporosis or hip fracture. Beneficiaries residing in regions in the midwest and south were more than twice as likely to receive propoxyphene as those in the mid-Atlantic area. CONCLUSION: These results show that propoxyphene use by U.S. community-dwelling seniors is high but is much higher in the institutionalized population. These findings suggest that prescribing for older adults with pain could be improved, especially for vulnerable long-term care residents.