The Price Elasticity of Specialty Drug Use: Evidence from Cancer Patients in Medicare Part D.

Specialty drugs can bring substantial benefits to patients with debilitating conditions, such as cancer, but their costs are very high. Insurers/payers have increased patient cost-sharing for specialty drugs to manage specialty drug spending. We utilized Medicare Part D plan formulary data to create the initial price (cost-sharing in the initial coverage phase in Part D), and estimated the total demand (both on- and off-label uses) for specialty cancer drugs among elderly Medicare Part D enrollees with no low-income subsidies (non-LIS) as a function of the initial price. We corrected for potential endogeneity associated with plan choice by instrumenting the initial price of specialty cancer drugs with the initial prices of specialty drugs in unrelated classes. We report three findings. First, we found that elderly non-LIS beneficiaries with cancer were less likely to use a Part D specialty cancer drug when the initial price was high: the overall price elasticity of specialty cancer drug spending ranged between -0.72 and -0.75. Second, the price effect in Part D specialty cancer drug use was not significant among newly diagnosed patients. Finally, we found that use of Part B-covered cancer drugs was not responsive to the Part D specialty cancer drug price. As the demand for costly specialty drugs grows, it will be important to identify clinical circumstances where specialty drugs can be valuable and ensure access to high-value treatments.

Nonlinear pricing in drug benefits and medication use: the case of statin compliance in Medicare Part D.

OBJECTIVE: To examine how enrollees' statin compliance responds to expected prices in Medicare Part D, which features a nonlinear price schedule due to a coverage gap. DATA SOURCES/STUDY SETTING: Prescription Drug Event data for a 5 percent random sample of Medicare Advantage Prescription Drug Plan enrollees in 2008 who did not receive a low-income subsidy. STUDY DESIGN: We analyze statin compliance prior to the coverage gap, where the "effective price" is higher than the actual copayment for drugs because consumers anticipate that more spending will make them more likely to reach the gap. We construct each enrollee's effective price as her expected price at the end of the year, which is the weighted average between pre-gap and in-gap copayments with the weight being the predicted probability of hitting the gap. Compliance is defined as at least 80 percent of days covered. PRINCIPAL FINDINGS: Part D enrollees' pre-gap statin compliance decreases by 3.7-4.7 percentage points for a $10 increase in the effective price. CONCLUSION: The presence of a coverage gap decreases statin compliance prior to the gap, suggesting that incorporating expected future prices is important to assess the full impact of cost sharing on drug compliance under nonlinear price schedules.

Demand for prescription drugs under non-linear pricing in Medicare Part D.

We estimate the price elasticity of prescription drug use in Medicare Part D, which features a non-linear price schedule due to a coverage gap. We analyze patterns of drug utilization prior to the coverage gap, where the "effective price" is higher than the actual copayment for drugs because consumers anticipate that more spending will make them more likely to reach the gap. We find that enrollees' total pre-gap drug spending is sensitive to their effective prices: the estimated price elasticity of drug spending ranges between [Formula: see text]0.14 and [Formula: see text]0.36. This finding suggests that filling in the coverage gap, as mandated by the health care reform legislation passed in 2010, will influence drug utilization prior to the gap. A simulation analysis indicates that closing the gap could increase Part D spending by a larger amount than projected, with additional pre-gap costs among those who do not hit the gap.

National trends in surgical therapy for benign prostatic hyperplasia in the United States (2000-2008).

OBJECTIVE: To report an update of the change in usage trends for different surgical treatments of benign prostatic hyperplasia (BPH) among the United States Medicare population data from 2000-2008. The rate of usage of thermotherapy and laser therapy in the surgical treatment of BPH has been changing over the past decade in conjunction with a steady decrease of transurethral resection of the prostate (TURP). METHODS: Using the 100% Medicare carrier file for the years 2000-2008, we calculated counts and population-adjusted rates of BPH surgery. Rates of TURP, thermotherapy, and laser-using modalities were calculated and compared in relation to age, race, clinical setting, and reimbursement. RESULTS: After years of a steady rise, the total rate of all BPH procedures peaked in 2005 at 1078/100,000 and then declined by 15.4% to 912/100,000 in 2008. TURP rates continued to decline from 670 in 2000 to 351/100,000 in 2008. Rates of microwave thermoablation peaked in 2006 at 266/100,000 and then declined 26% in 2008. Laser vaporization almost completely replaced laser coagulation and in 2008 was the most commonly performed procedure second to TURP, with the majority performed as outpatient procedures (70%) and an increasing percentage in the office (12%). Men between ages 70 and 75 had the highest rate of procedures. Reimbursement rates correlate using some but not all procedures. Racial disparities reported previously appear to have resolved. CONCLUSION: Surgical treatment of BPH continues to change rapidly. TURP continues to decline and laser vaporization is the fastest growing modality. There is a big shift toward outpatient/office procedures. Reimbursement rates do not appear to have a consistent effect on usage.

Comparison of statin adherence among beneficiaries in MA-PD plans versus PDPs.

BACKGROUND: Medicare Part D, which provides prescription drug coverage to Medicare beneficiaries, is delivered through either Medicare Advantage prescription drug (MA-PD) plans or stand-alone prescription drug plans (PDPs). MA-PD plans cover both drug therapy and other medical services, whereas PDPs provide prescription drug coverage only. Because of the potential substitutability between prescription drugs and other medical services, MA-PD plans may make greater efforts to improve enrollees' adherence to recommended medications than PDPs. Prescription drug benefits are more generous in MA-PD plans than in PDPs. OBJECTIVE: To assess statin adherence, comparing Medicare beneficiaries in MA-PD plans with those in PDPs. METHODS: We used records from the Chronic Condition Warehouse 2007 Prescription Drug Event (PDE) file, associated Plan Characteristics files, and the Beneficiary Summary File (BSF) for a 5% random sample of Medicare beneficiaries. The study sample comprised Medicare beneficiaries aged 65 years or older in 2006 who filled at least 1 prescription for a statin during 2007, excluding beneficiaries with low-income subsidy or end-stage renal disease and those without both Medicare Part A and Part B enrollment in 2007. Medication adherence was measured by medication possession ratio (MPR), defined as the sum of days supply for all statin prescriptions filled in 2007 minus the days supply that would have carried over into 2008 from the final 2007 prescription filled, divided by the total number of days from the fill date of the first statin prescription to December 31, 2007. A binary indicator of good adherence was defined as MPR exceeding 80%. Propensity-score matching was used to reduce differences in observed characteristics of enrollees in MA-PD plans and PDPs. The propensity score was based on sociodemographic characteristics and health risk measures, including Hierarchical Condition Category (HCC) scores. RESULTS: In the unmatched sample, the mean MPR was 70.57% for MA-PD enrollees versus 70.54% for PDP enrollees (P = 0.780), and the proportion of enrollees with good adherence was 46.7% for MA-PD plans versus 46.9% for PDPs (P = 0.262). In the matched sample, statin adherence was slightly better among MA-PD enrollees than PDP enrollees. Mean MPRs were 70.80% and 69.44%, and the percentages of enrollees with good adherence were 47.0% and 45.3% in MA-PD plans and PDPs, respectively (both P less than 0.001). CONCLUSIONS: During an early year of the Part D program, MA-PD enrollees had slightly better adherence to statin therapy than PDP enrollees. While the difference was statistically significant, it was very small and unlikely to lead to clinically meaningful consequences. Less than one-half of MA-PD and PDP enrollees had good adherence in statin use, suggesting room for improvement in both types of Part D plans. Continuing evaluations of adherence in diverse therapy classes are needed for Medicare Part D beneficiaries.

Screening mammography rate and predictors following treatment for colorectal cancer.

INTRODUCTION: Colorectal cancer survivors remain at risk for breast cancer. Thus, it is important to determine if screening mammography rates are reduced by the diagnosis and treatment of incident colorectal cancer. METHODS: Mammography rates among 7,666 67-79 year-old stage 0-III colorectal cancer survivors were compared with rates among 36,433 age-, race/ethnicity-, SEER area-matched women controlling for pre-diagnosis mammography, stage, chemotherapy, income, co-morbidities, treatment in teaching hospital, number of physician visits, and gynecologist visits. RESULTS: In the first 2 years after diagnosis, the survivors' rate (49.7/100) was 4.2% higher than the controls' (47.6/100), p < 0.001. It was 7.5% higher in the next 2 years, 54.5/100 versus 49.7/100, p < 0.001. The higher rates resulted from significantly greater rates among survivors without prior mammography, 30.9/100, compared with their controls (25.3/100) in the first 2 years, for example (O.R. = 1.23, 95% C.I. = 1.15-1.32). The strongest predictors of post-diagnosis mammography were pre-diagnosis mammography (O.R. = 5.76, 95% C.I. = 5.19-6.38), visiting a gynecologist (O.R. = 1.83, 95% C.I. = 1.55-2.16), chemotherapy (O.R. = 1.61, 95% C.I. = 1.40-1.86), and more than nine physician visits. Increasing Charlson scores and cancer stage were associated with lower mammography rates. DISCUSSION/CONCLUSIONS: Overall, the competing demands of cancer diagnosis and treatment did not reduce mammography rates, and these events were associated with increased rates among previous non-users. IMPLICATIONS FOR CANCER SURVIVORS: The low mammography rate among survivors with no history of a prior mammogram means that the physicians treating these women must emphasize the need for such care.

Practice patterns in benign prostatic hyperplasia surgical therapy: the dramatic increase in minimally invasive technologies.

PURPOSE: We describe the trends in transurethral prostatectomy and minimally invasive surgical treatments for benign prostate hyperplasia from 1999 through 2005 among elderly male Medicare beneficiaries. MATERIALS AND METHODS: Benign prostatic hyperplasia surgeries were identified using the annual 100% Medicare carrier files which contain physician claims for services reimbursed under Medicare Part B. The annual age group specific procedure rates as well as the age adjusted rates by race and percent of each procedure performed in different clinical settings were calculated. RESULTS: The total number of benign prostatic hyperplasia procedures increased 44% from 88,868 in 1999 to 127,786 in 2005. The minimally invasive surgical treatment procedure counts increased 529% from 11,582 to 72,887 and the rates increased 439% from 136 to 678 per 100,000 males during that period. The transurethral prostate resection rate decreased approximately 5% per year. By 2005 minimally invasive surgical treatment procedures accounted for 57% of total benign prostatic hyperplasia surgeries, while transurethral prostate resection accounted for only 39%. Almost all transurethral microwave thermotherapy, 86% of transurethral needle ablation and 54% of laser coagulation procedures were performed in office clinics, and 78% of laser vaporization procedures were performed in hospital outpatient clinics. Black beneficiaries were 17% less likely to receive minimally invasive surgical treatment than whites in 2005. CONCLUSIONS: The increase of total benign prostatic hyperplasia procedure rate was driven by a marked increase in minimally invasive surgical treatment and a continuing decrease of transurethral prostate resection. Differences in the use of minimally invasive surgical treatment across age and racial groups persisted. This dramatic change in the pattern of benign prostatic hyperplasia surgical treatment may have a profound impact on health care expenditures and outcomes, and requires further investigation.

The use of preventive health services among elderly uterine cancer survivors.

OBJECTIVE: The purpose of the study was to determine whether women who survived uterine cancer received 4 recommended preventive services (mammography, colorectal cancer screening, influenza immunization, and bone density testing) at the same rates as women with no history of cancer. STUDY DESIGN: We used the Surveillance, Epidemiology, and End Results-Medicare database to compare the rates among survivors aged 67 years or older with a matched group of women with no history of cancer. RESULTS: Survivors were significantly more likely to have a mammogram (adjusted odds ratio [OR], 1.40; 95% confidence interval [CI], 1.30-1.50) or a colorectal cancer screening examination (adjusted OR, 1.11; 95% CI, 1.05-1.18). Influenza immunization and bone density testing rates were similar. The 28% of survivors seen by an obstetrician-gynecologist or gynecologic oncologist had the highest rates of use. CONCLUSION: Efforts need to be made to increase the use of services by all women to achieve the target rates established by Healthy People 2010.

The underuse of screening services among elderly women with diabetes.

OBJECTIVE: To determine whether the use of nondiabetes-related preventive services (mammography, colorectal cancer screening, and bone density testing) among elderly diabetic women is different from the use among nondiabetic women. RESEARCH DESIGN AND METHODS: Using a representative sample of the U.S. elderly female population and the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare files, we identified women with or without diabetes who were > or =67 years of age on 1 January 1999. All women with a prior history of cancer were excluded. Bivariate and multivariate analyses were used to compare the rates of preventive service use and to understand the factors influencing their use in the next 2-4 years. RESULTS: Women with diabetes were less likely to have a mammogram (odds ratio [OR] 0.83 [95% CI 0.78-0.88]), colorectal cancer screening (0.79 [0.70-0.88]), and bone density testing (0.63 [0.58-0.69]). Women with diabetes seen by endocrinologists had significantly higher rates of bone density testing than women seen by primary care physicians. Women seen by obstetrician/gynecologists had the highest rates of use of all three services. CONCLUSIONS: Elderly women with diabetes are less likely to receive cancer and osteoporosis screening than women without diabetes. Physicians treating these patients need to assure that they receive all recommended preventive services appropriate for their age. Additional national guidelines, practice-based improvements, and patient education targeting those at greatest risk of not receiving these services may be needed to achieve parity.

Physician visits, patient comorbidities, and mammography use among elderly colorectal cancer survivors.

INTRODUCTION: Over a million Americans have survived colorectal cancer. This study examined physician visit patterns, patient comorbidities, and mammography use among colorectal cancer survivors based on the competing demands model. METHODS: Using Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data (2003 merge), study cohorts included female colorectal cancer patients who were diagnosed from 1973 through 1994 and had survived five or more years after the cancer diagnosis (n = 12,681), and a non-cancer comparison population who had no history of cancer and resided in the SEER areas during the study period. RESULTS: Cancer survivors had a significant 6% higher mammography rate during 2000 to 2001 than matched women with no history of cancer (50 vs 47 per 100 persons, respectively). Among cancer survivors, there was a significant and positive association between the number of physician visits for evaluation and management (E&M) and mammography rates. More physician visits for E&M reduced the differences of mammography rates between those with and without additional comorbidities. Cancer survivors who visited gynecologists for E&M were 45% more likely to receive mammograms than those who visited only primary care physicians (multivariate adjusted rate ratio, 1.45; 95% CI, 1.38-1.53). CONCLUSIONS: Elderly female colorectal cancer survivors were more likely to receive mammograms than matched women with no history of cancer. IMPLICATIONS FOR CANCER SURVIVORS: Patients with multiple comorbidities might receive more mammograms by increasing the number of office visits for E&M and by visiting gynecologists. Primary care physicians should increase the priority for recommending mammograms among cancer survivors.

Improving Medicare's data on race and ethnicity.

Medicare's databases provide a rich source of information about the program's 43 million beneficiaries. These data have played an important role in documenting racial, ethnic, and socioeconomic disparities in health and health care. Because they derive largely from administrative records that have been collected over many years using varying standards, however, they are not fully adequate for monitoring and reducing disparities. The Centers for Medicare & Medicaid Services (CMS) has supported a number of initiatives to improve the quality of its data on race and ethnicity. Yet analyses of 2002 Medicare administrative data show that only 52 percent of Asian beneficiaries and 33 percent of both Hispanic and American Indian/Alaska Native beneficiaries were identified correctly. As CMS moves to reduce disparities, and as researchers strive to explain how and why disparities occur, further improvements in Medicare's data are essential. Health care organizations also need data on the race and ethnicity of the people they serve in order to improve the quality of care for minorities. This brief provides some recommendations for further efforts.

Modelling geographically referenced survival data with a cure fraction.

The emergence of geographical information systems and related softwares nowadays enables medical databases to incorporate the geographical information on patients, allowing studies in spatial associations. Public health administrators and researchers are often interested in detecting variation in survival patterns by region or county in order to understand the possible factors that contribute towards such spatial discrepancies. These issues have led statisticians to develop survival models that account for spatial clustering and variation. Additionally, with rapid developments in medical and health sciences, researchers increasingly encounter data sets where a substantial portion of patients are cured. Models accounting for cure in the population assist in the prognosis of potentially terminal diseases. This article proposes a Bayesian modelling framework that models spatial associations for areally referenced survival data using a general class of cure models proposed by Cooner et al. The special models we outline are alternatives to the traditional proportional hazards models and can be fitted using standard Bayesian software such as WinBUGS.

Decreasing invasive pneumococcal disease in the elderly: a state-level analysis.

Evidence has accumulated supporting the relationship between the use of 7-valent pneumococcal conjugate vaccine (PCV7) in children and a decline in invasive pneumococcal disease (IPD) in the elderly. We conducted a state-level analysis of vaccination coverage rates among children 19-35 months of age and IPD hospitalization rates among elderly Medicare beneficiaries. Simple correlations were suggestive of a negative relationship. Multivariate analysis using a state fixed-effect model which helped control for the time invariant factors at the state level also indicated a negative relationship, and it was statistically significant, p = 0.035. The relationship between the use of 23-valent pneumococcal polysaccharide vaccine (PPV23) and IPD hospitalizations was not statistically significant using either method.

Unequal use of new technologies by race: the use of new prostate surgeries (transurethral needle ablation, transurethral microwave therapy and laser) among elderly Medicare beneficiaries.

PURPOSE: We compared the availability and use of transurethral microwave therapy, transurethral needle ablation, contact or noncontact laser therapy and transurethral resection of the prostate among elderly black and white Medicare beneficiaries. MATERIALS AND METHODS: We examined 100% Medicare Inpatient, Outpatient, Carrier and Denominator files of men 65 years old or older who underwent these procedures in 1999 through 2001. White-to-black race rate ratios for each procedure were computed for the entire United States, as well as for a restricted set of counties in which procedures were available to black beneficiaries. RESULTS: A total of 170,067 TURP, 16,953 TUMT, 5,353 TUNA and 12,134 Laser procedures were performed during 3 years. Nationally there was only a 3% difference in the age adjusted TURP rates between white and black men (6.13 and 5.94 per 1,000 person-years, respectively). However, the age adjusted rates for TUMT and TUNA among white men were about twice those among black men (0.63 vs 0.31 and 0.20 vs 0.10 per 1,000 person-years, respectively). Laser rates were 17% higher among white men than among black men (0.44 vs 0.38 per 1,000 person-years). Large geographic variation existed in the new procedure rates. Negative binomial regression analysis confirmed the national findings in those counties in which the procedures were available to black men. Adjusted white-to-black rate ratios were 1.96 (95% CI 1.70-2.25) for TUMT, 2.33 (95% CI 1.87-2.90) for TUNA and 1.36 (95% CI 1.16-1.59) for Laser. CONCLUSIONS: After controlling for availability, elderly black Medicare beneficiaries were less likely to undergo the new BPH procedures than white beneficiaries, while the usage difference for TURP remained small.

Alcohol consumption in older adults and Medicare costs.

We determined the relationship of alcohol consumption and Medicare costs among 4,392 participants in the Cardiovascular Health Study (CHS), a longitudinal, population-based cohort study of adults age 65 or over in four U.S. communities. We assessed 5-year Parts A and B costs and self-reported intake of beer, wine, and liquor at baseline. Among both sexes, total costs were approximately $2,000 lower among consumers of > 1-6 drinks per week than abstainers. The lower costs associated with moderate drinking were most apparent among participants with cardiovascular disease (CVD) and for hospitalization costs for CVD among healthy participants. Former drinkers had the highest costs.

Explaining trends in hospitalizations for pneumonia and influenza in the elderly.

From 1987-99, influenza and pneumococcal vaccination rates among elderly Medicare beneficiaries increased by 300 percent and 500 percent, respectively. Despite these gains, annual rates of hospitalizations for pneumonia and influenza (P&I) have not decreased; rather, they have increased steadily. The authors investigate whether this paradoxical increase in hospitalization rates reflects an increasing burden of P&I or the effects of a changing healthcare environment. They find that from 1987-99, P&I hospitalizations per one thousand beneficiaries increased from 15.1 to 23.4. Of this increase, 23 percent was due to an aging Medicare population, 2.4 percent was due to increased rates of rehospitalization, and at most 5 percent was due to upcoding. There was no evidence that physicians were increasingly admitting patients with less complicated cases of P&I. The changing healthcare environment only partially explained the paradoxical increase in P&I hospitalizations. P&I appears to be an increasing burden to the elderly, despite increased vaccination rates.

Declining invasive pneumococcal disease in the U.S. elderly.

In 2000, pneumococcal conjugate vaccine (PCV7) was recommended for young children. By 2002-2003, 48.6% had been fully immunized. Using Medicare administrative, we found that the rates of invasive pneumococcal disease (IPD) hospitalizations in the elderly in the 2000-2001, 2001-2002 and 2002-2003, were 22.6, 30.2, and 40.6% lower, respectively, than during the baseline period, 1996-1997 through 1999-2000 (range 35.1/100,000 to 38.3/100,000). Pneumococcal polysaccharide vaccine (PPV23) has been recommended for the elderly, since 1989. PPV23 vaccination rates in the elderly increased by 25.2% during the baseline period but by <5% during the period PCV7 has been available. Thus, during the period that PCV7 vaccine has been used in children, rates of IPD in the elderly have declined appreciably more compared to the immediately prior period when PPV23 was the only vaccine available.

Long-term sequelae of hemorrhagic fever with renal syndrome attributable to hantaan virus in Korean War veterans.

Health status was sought for approximately 1600 Korean War veterans who contracted hemorrhagic fever with renal syndrome (HFRS) during deployment to Korea between 1951 and 1953. To determine whether long-term sequelae were present for these individuals, mortality and morbidity data were collected from the Department of Veterans Affairs, the Centers for Medicare and Medicaid Services, the Social Security Administration, and the National Death Index records. Control subjects were selected from military units in Korea with no reported cases of HFRS. Those with HFRS had a slightly higher mortality rate (33.2%) than did noninfected individuals (32.0%), but this difference was not statistically significant. Non-Caucasian cases had significantly higher morbidity rates than did non-Caucasian controls only for transient ischemic attacks (4.8% versus 0%) and diabetes mellitus (19.3% versus 8.1%). In conclusion, HFRS did not increase mortality rates in this cohort but might have had an impact on selected morbidity outcomes.

Improved care and outcomes among elderly medicare managed care beneficiaries with diabetes.

OBJECTIVE: To examine individual- and plan-level factors related to improved diabetes care and outcomes between 1999 and 2001 among elderly Medicare managed care beneficiaries with diabetes. STUDY DESIGN: Retrospective analysis of Medicare and individual-level Health Plan and Employer Data Information Set data. METHODS: We merged Medicare demographic information with person-level data regarding 6 comprehensive diabetes care measures provided by the National Committee on Quality Assurance for Medicare managed care enrollees for 1999. Then we identified those beneficiaries for whom comprehensive diabetes care information was also reported in 2001, and determined the improvement for each measure. Data on persons not meeting the comprehensive diabetes care criteria in 1999 were analyzed to determine the factors associated with appropriate care and outcomes in 2001. RESULTS: Of the 174 combinations of individual- or plan-level factors and comprehensive diabetes care measures, 167 showed significant improvements. Nonetheless, for most of the 6 comprehensive diabetes care measures, poor care occurred more frequently for black patients than for white patients, among individuals in for-profit versus not for profit plans, and among individuals in independent practice association plans compared with group and staff model plans. Among the beneficiaries whose healthcare failed to meet the comprehensive diabetes care guidelines in 1999, by 2001, care guidelines were met in approximately three fourths for hemoglobin A1c and low-density lipoprotein cholesterol testing, but in only one half for eye examinations, low-density lipoprotein cholesterol control, and nephropathy monitoring. CONCLUSIONS: Between 1999 and 2001, care of elderly Medicare patients with diabetes improved, including among individuals who previously had not received appropriate care. However, more improvement is needed to achieve equality among members of all race groups and plan types.

The causes of racial and ethnic differences in influenza vaccination rates among elderly Medicare beneficiaries.

OBJECTIVE: To explore three potential causes of racial/ethnic differences in influenza vaccination rates in the elderly: (1) resistant attitudes and beliefs regarding vaccination by African-American and Hispanic Medicare beneficiaries, (2) poor access to care during influenza vaccination weeks, and (3) discriminatory behavior by providers. DATA SOURCES: Medicare beneficiaries who responded to both the 1995 and 1996 Medicare Current Beneficiary Survey (MCBS) (n=6,746). STUDY DESIGN: We combined survey information from the MCBS with Medicare claims. We measured resistance to vaccination by self-reported reasons for not receiving vaccination, access to care by claims submitted during vaccination weeks, and discrimination by racial differences in vaccinations among beneficiaries who visited the same providers during vaccination weeks. PRINCIPAL FINDINGS: White beneficiaries (66.6 percent) were more likely to self-report having received vaccination than were African Americans (43.3 percent) or Hispanics (52.5 percent). Resistance to vaccination plays a role in low vaccination rates of African-American (-11.8 percentage points), but not Hispanic beneficiaries. Unequal access accounts for <2 percent of the disparity. Minority beneficiaries remained unvaccinated despite having medical encounters with their usual providers on days when those same providers were administering vaccinations to white beneficiaries. This disparity is attributable not to provider discrimination but to a 1.6-5 x higher likelihood of white beneficiaries initiating encounters for the purpose of receiving vaccination. CONCLUSION: Disparities in access to care and provider discrimination play little role in explaining racial/ethnic disparities in influenza vaccination. Eliminating missed opportunities for vaccination in 1995 would have raised vaccination rates in three racial/ethnic groups to the Healthy People 2000 goal of 60 percent vaccination.