Amyloid Positron Emission Tomography and Subsequent Health Care Use Among Medicare Beneficiaries With Mild Cognitive Impairment or Dementia.

Importance: Results of amyloid positron emission tomography (PET) have been shown to change the management of patients with mild cognitive impairment (MCI) or dementia who meet Appropriate Use Criteria (AUC). Objective: To determine if amyloid PET is associated with reduced hospitalizations and emergency department (ED) visits over 12 months in patients with MCI or dementia. Design, Setting, and Participants: This nonrandomized controlled trial analyzed participants in the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) study, an open-label, multisite, longitudinal study that enrolled participants between February 2016 and December 2017 and followed up through December 2018. These participants were recruited at 595 clinical sites that provide specialty memory care across the US. Eligible participants were Medicare beneficiaries 65 years or older with a diagnosis of MCI or dementia within the past 24 months who met published AUC for amyloid PET. Each IDEAS study participant was matched to a control Medicare beneficiary who had not undergone amyloid PET. Data analysis was conducted on December 13, 2022. Exposure: Participants underwent amyloid PET at imaging centers. Main Outcomes and Measures: The primary end points were the proportions of patients with 12-month inpatient hospital admissions and ED visits. One of 4 secondary end points was the rate of hospitalizations and rate of ED visits in participants with positive vs negative amyloid PET results. Health care use was ascertained from Medicare claims data. Results: The 2 cohorts (IDEAS study participants and controls) each comprised 12 684 adults, including 6467 females (51.0%) with a median (IQR) age of 77 (73-81) years. Over 12 months, 24.0% of the IDEAS study participants were hospitalized, compared with 25.1% of the matched control cohort, for a relative reduction of -4.49% (97.5% CI, -9.09% to 0.34%). The 12-month ED visit rates were nearly identical between the 2 cohorts (44.8% in both IDEAS study and control cohorts) for a relative reduction of -0.12% (97.5% CI, -3.19% to 3.05%). Both outcomes fell short of the prespecified effect size of 10% or greater relative reduction. Overall, 1467 of 6848 participants (21.4%) with positive amyloid PET scans were hospitalized within 12 months compared with 1081 of 4209 participants (25.7%) with negative amyloid PET scans (adjusted odds ratio, 0.83; 95% CI, 0.78-0.89). Conclusions and Relevance: Results of this nonrandomized controlled trial showed that use of amyloid PET was not associated with a significant reduction in 12-month hospitalizations or ED visits. Rates of hospitalization were lower in patients with positive vs negative amyloid PET results.

A trans-omics assessment of gene-gene interaction in early-stage NSCLC.

Epigenome-wide gene-gene (G × G) interactions associated with non-small-cell lung cancer (NSCLC) survival may provide insights into molecular mechanisms and therapeutic targets. Hence, we proposed a three-step analytic strategy to identify significant and robust G × G interactions that are relevant to NSCLC survival. In the first step, among 49 billion pairs of DNA methylation probes, we identified 175 775 G × G interactions with PBonferroni ≤ 0.05 in the discovery phase of epigenomic analysis; among them, 15 534 were confirmed with P ≤ 0.05 in the validation phase. In the second step, we further performed a functional validation for these G × G interactions at the gene expression level by way of a two-phase (discovery and validation) transcriptomic analysis, and confirmed 25 significant G × G interactions enriched in the 6p21.33 and 6p22.1 regions. In the third step, we identified two G × G interactions using the trans-omics analysis, which had significant (P ≤ 0.05) epigenetic cis-regulation of transcription and robust G × G interactions at both the epigenetic and transcriptional levels. These interactions were cg14391855 × cg23937960 (ßinteraction  = 0.018, P = 1.87 × 10-12 ), which mapped to RELA × HLA-G (ßinteraction  = 0.218, P = 8.82 × 10-11 ) and cg08872738 × cg27077312 (ßinteraction  = -0.010, P = 1.16 × 10-11 ), which mapped to TUBA1B × TOMM40 (ßinteraction =-0.250, P = 3.83 × 10-10 ). A trans-omics mediation analysis revealed that 20.3% of epigenetic effects on NSCLC survival were significantly (P = 0.034) mediated through transcriptional expression. These statistically significant trans-omics G × G interactions can also discriminate patients with high risk of mortality. In summary, we identified two G × G interactions at both the epigenetic and transcriptional levels, and our findings may provide potential clues for precision treatment of NSCLC.

Risk of stroke after chiropractic spinal manipulation in medicare B beneficiaries aged 66 to 99 years with neck pain.

OBJECTIVE: The purpose of this study was to quantify risk of stroke after chiropractic spinal manipulation, as compared to evaluation by a primary care physician, for Medicare beneficiaries aged 66 to 99 years with neck pain. METHODS: This is a retrospective cohort analysis of a 100% sample of annualized Medicare claims data on 1 157 475 beneficiaries aged 66 to 99 years with an office visit to either a chiropractor or primary care physician for neck pain. We compared hazard of vertebrobasilar stroke and any stroke at 7 and 30 days after office visit using a Cox proportional hazards model. We used direct adjusted survival curves to estimate cumulative probability of stroke up to 30 days for the 2 cohorts. RESULTS: The proportion of subjects with stroke of any type in the chiropractic cohort was 1.2 per 1000 at 7 days and 5.1 per 1000 at 30 days. In the primary care cohort, the proportion of subjects with stroke of any type was 1.4 per 1000 at 7 days and 2.8 per 1000 at 30 days. In the chiropractic cohort, the adjusted risk of stroke was significantly lower at 7 days as compared to the primary care cohort (hazard ratio, 0.39; 95% confidence interval, 0.33-0.45), but at 30 days, a slight elevation in risk was observed for the chiropractic cohort (hazard ratio, 1.10; 95% confidence interval, 1.01-1.19). CONCLUSIONS: Among Medicare B beneficiaries aged 66 to 99 years with neck pain, incidence of vertebrobasilar stroke was extremely low. Small differences in risk between patients who saw a chiropractor and those who saw a primary care physician are probably not clinically significant.

Varied differences in the health status between Medicare advantage and fee-for-service enrollees.

This article examines the differences in mortality measured health status between the Medicare Advantage (MA) program and Fee-for-Service (FFS) program from 1999 to 2007. At the national level, differences in mortality rates were associated with MA market share. In some counties, enrollees in the MA program were 40% less likely to die than their peers in the FFS program, but in other counties, they were 20% more likely to die. Cost shifting between the two programs could bias county classifications of average FFS spending, and enlarged disparities in health status could make it difficult to evaluate risk adjusters.

Intended versus inferred care after PET performed for initial staging in the National Oncologic PET Registry.

UNLABELLED: The National Oncologic PET Registry (NOPR) collected data on intended management before and after PET in cancer patients. We have previously reported that PET was associated with a change in intended management of about one third of patients and was consistent across cancer types. It is uncertain if intended management plans reflect the actual care these patients received. One approach to assess actual care received is using administrative claims to categorize the type and timing of clinical services. METHODS: NOPR data from 2006 to 2008 were linked to Medicare claims for consenting patients aged 65 y or older undergoing initial-staging PET scanning for bladder, ovarian, pancreatic, small cell lung, or stomach cancers. We determined the 60-d agreement between claims-inferred care and NOPR treatment plans. RESULTS: Patients (n = 4,661) were assessed, and 30%-52% had metastatic disease. Planned treatments were about two-thirds monotherapy, of which 46% was systemic therapy only, and one-third combinations. Claims paid by 60 d confirmed the NOPR plan of any systemic therapy, radiotherapy, or surgery in 79.3%, 64.7%, and 63.6%, respectively. Single-mode plans were much more often confirmed: systemic therapy in more than 85% of patients with ovarian, pancreatic, and small cell lung cancers and surgery in more than 73% of those with bladder, pancreatic, and stomach cancers. Intended combination treatments had claims for both in only 28% of patients receiving surgery-based combinations and in 55% receiving chemoradiotherapy. About 90% of patients with NOPR-planned systemic therapy had evaluation or management claims from a medical oncologist. An age of less than 75 y was associated more often with confirmation of chemotherapy, less often for radiotherapy but not with confirmation of surgery. Performance status or comorbidity did not explain confirmation rates within action categories, but confirmation rates were higher if the referrer specialized in the planned treatment. CONCLUSION: Claims confirmations of NOPR intent for initial staging were widely variable but were higher than previously reported for restaging PET, suggesting that measuring change in intended management is a reasonable method for assessing the impact diagnostic tests have on actual care.

Trends in the use and cost of chiropractic spinal manipulation under Medicare Part B.

BACKGROUND CONTEXT: Concern about improper payments to chiropractic physicians prompted the US Department of Health and Human Services to describe chiropractic services as a "significant vulnerability" for Medicare, but little is known about trends in the use and cost of chiropractic spinal manipulation provided under Medicare. PURPOSE: To quantify the volume and cost of chiropractic spinal manipulation services for older adults under Medicare Part B and identify longitudinal trends. STUDY DESIGN/SETTING: Serial cross-sectional design for retrospective analysis of administrative data. PATIENT SAMPLE: Annualized nationally representative samples of 5.0 to 5.4 million beneficiaries. OUTCOME MEASURES: Chiropractic users, allowed services, allowed charges, and payments. METHODS: Descriptive statistics were generated by analysis of Medicare administrative data on chiropractic spinal manipulation provided in the United States from 2002 to 2008. A 20% nationally representative sample of allowed Medicare Part B fee-for-service claims was merged, based on beneficiary identifier, with patient demographic data. The data sample was restricted to adults aged 65 to 99 years, and duplicate claims were excluded. Annualized estimates of outcome measures were extrapolated, per beneficiary and per user rates were estimated, and volumes were stratified by current procedural terminology code. RESULTS: The number of Medicare beneficiaries who used chiropractic spinal manipulation grew 13% from 2002 to 2004, remained flat through 2007, and then declined 5% through 2008. An estimated 1.7 million beneficiaries (6.9%) used 18.6 million allowed chiropractic services in 2008. In inflation-adjusted dollars, allowed charges per user increased 4% through 2005 and then declined by 17% through 2008; payments per user increased by 5% from 2002 to 2005 and then declined by 18% through 2008. Expenditures for chiropractic in 2008 totaled an estimated $420 million. Longitudinal trends in allowed claims for spinal manipulation varied by procedure: the relative frequency of treatment of one to two spinal regions declined from 43% to 29% of services, treatment of three to four regions increased from 48% to 62% of services, and treatment of five regions remained flat at 9% of services. CONCLUSIONS: Chiropractic claims account for less than 1/10th of 1% of overall Medicare expenditures. Allowed services, allowed charges, and fee-for-service payments for chiropractic spinal manipulation under Medicare Part B generally increased from 2002, peaked in 2005 and 2006, and then declined through 2008. Per user spending for chiropractic spinal manipulation also declined by 18% from 2006 to 2008, in contrast to 10% growth in total spending per beneficiary and 16% growth in overall Medicare spending.

Intended versus inferred management after PET for cancer restaging: analysis of Medicare claims linked to a coverage with evidence development registry.

BACKGROUND: The National Oncologic PET Registry (NOPR) ascertained changes in the intended management of cancer patients using questionnaire data obtained before and after positron emission tomography (PET) under Medicare's coverage with evidence development policy. OBJECTIVE: To assess the concordance between intended care plans and care received as ascertained through administrative claims data. RESEARCH DESIGN: Analysis of linked data of NOPR participants from 2006 to 2008 and their corresponding Medicare claims. SUBJECTS: Consenting patients aged older than 65 years having their first PET for restaging of bladder, kidney, ovarian, pancreas, prostate, small cell lung, or stomach cancer. MEASURES: : Agreement (positive predictive values and κ) between NOPR post-PET intended management plans for treatment (systemic therapy, radiotherapy, surgery, or combinations), biopsy, or watching as compared to claims-inferred care 30 days after PET. RESULTS: A total of 8460 patients with linked data were assessed. A total of 43.5% had metastatic disease and 45.3% had treatment planned (predominantly systemic therapy only), 11.1% biopsy and 43.5% watching. Claims-confirmed intended plans (positive predictive value) for single-mode systemic therapy in 62.0%, radiation in 66.0%, surgery in 45.6%, and biopsy in 55.7%. A total of 25.7% of patients with a plan of watching had treatment claims. By cancer type, κ ranged for systemic therapy only from 0.17 to 0.40 and for watching from 0.21 to 0.41. Agreement rates varied by cancer types but were minimally associated with patient age, performance status, comorbidity, or stage. CONCLUSIONS: Among elderly cancer patients undergoing PET for restaging, there was moderate concordance between their physicians' planned management and claims-inferred actions within a narrow time window. When higher accuracy levels are required in future coverage with evidence development studies, alternative designs will be needed.

Racial disparities in the use of chiropractic care under Medicare.

CONTEXT: Medicare covers chiropractic care, but the health-care community knows little about the demographic characteristics of older adults who use chiropractic services under the Medicare program. Researchers do not know the demographic composition of chiropractic users under Medicare, how the demographics of chiropractic use and rates of use have changed over time, and how users' characteristics vary geographically across the United States. An understanding of the demographics of chiropractic users can help chiropractic organizations, policy makers, and other stakeholders plan for an equitable allocation of resources to meet the chiropractic health-care needs of all of Medicare's beneficiaries. OBJECTIVE: The study intended to evaluate Medicare administrative data to determine (1) longitudinal trends in the demographic composition of the population that used chiropractic services, (2) longitudinal trends in rates of chiropractic use by demographic group, and (3) geographic variations in chiropractic use among minorities. DESIGN: The research team used a serial cross-sectional design to analyze administrative data for beneficiaries of Medicare during the years 2002 to 2008, using a 20% random sample that provided those beneficiaries' racial and geographical characteristics. The team restricted the study's actual sample to adults aged 65 to 99 and defined chiropractic users as beneficiaries who had at least one paid claim for chiropractic care on a date of service in an analyzed calendar year. OUTCOME MEASURE(S): For each state in the United States and the District of Columbia for each of the 7 years studied, the team determined the number of chiropractic users in total and the number of users in selected demographic categories and calculated percentage estimates and averages for each category. The team analyzed 2008 data for rates of use within racial groups and for geographic variations in those rates and quantified variations in rates by state using the coeffcient of variation (CV). The team mapped race-specific rates for selected minorities, categorized by quintiles, to illustrate geographic variations by state. RESULTS: Analysis by beneficiary's race showed that the proportion of chiropractic users who were white hovered at 96% to 97% throughout the time period studied, while 1% to 2% were black. Each of the other racial categories comprised 1% or less of users, and the percentages showed little change over time. Rates among racial minorities showed greater geographic variation than did rates for whites. The greatest geographic variations in use by specific racial minorities occurred among Hispanics, Asians, and Native Americans. CONCLUSION: The research team's results showed little longitudinal variation in the demographics of chiropractic use under Medicare but a striking difference in rates of use between whites and minorities, and substantial geographic variations in user rates among racial minorities. The research team's findings suggest the possibility that barriers may exist for minorities' access to chiropractic care. As minority populations in the United States continue to grow, the health-care community can expect that any impact on population health that these barriers cause will grow as well.

Geographic and sociodemographic disparities in PET use by Medicare beneficiaries with cancer.

PURPOSE: PET use for cancer care has increased unevenly, possibly because of regional health care market characteristics or underlying population characteristics. The aim of this study was to examine variation in advanced imaging use among individuals with cancer in relation to population and hospital service area (HSA) characteristics. METHODS: A retrospective national study of fee-for-service Medicare beneficiaries with diagnoses of 1 of 5 cancers covered by Medicare for PET (2004-2008) was conducted. Crude and adjusted rates of PET, CT, and MRI were estimated for HSAs and sociodemographic subgroups. Generalized linear mixed models were used to assess the effects of race/ethnicity, area-level income, and HSA-level physician supply and spending on imaging utilization. RESULTS: On the basis of an annual average of 116,452 beneficiaries with cancer, adjusted PET rates (imaging days per person-year) showed significantly higher use for whites compared with blacks in both 2004 (whites, 0.35 [95% confidence interval, 0.34-0.36]; blacks, 0.31 [95% confidence interval, 0.30-0.33]) and 2008 (whites, 0.64 [95% confidence interval, 0.63-0.65]; blacks, 0.57 [95% confidence interval, 0.55-0.59]). This trend was similar for the highest quartile of group-level median household income but was opposite for CT use, with blacks having higher rates than whites. The highest Medicare-spending HSAs had significantly higher adjusted PET rates compared with lower spending areas (0.57 [95% confidence interval, 0.55-0.60] vs 0.69 [95% confidence interval, 0.67-0.71] imaging days/person-year). CONCLUSIONS: The use of PET among Medicare beneficiaries with cancer increased from 2004 to 2008, with higher rates observed among whites, among higher socioeconomic groups, and in higher Medicare spending areas. Sociodemographic differences in advanced imaging use are modality specific.

Use of chiropractic spinal manipulation in older adults is strongly correlated with supply.

STUDY DESIGN: Retrospective cross-sectional analysis of administrative data. OBJECTIVE: To examine the relationship between regional chiropractic supply and both use and utilization intensity of chiropractic services among Medicare beneficiaries. SUMMARY OF BACKGROUND DATA: Numerous studies have documented trends and patterns in the utilization of chiropractic services in the United States, but little is known about geographic variation in the relationship between chiropractic supply and utilization. METHODS: We analyzed Medicare claims data for services provided by chiropractic physicians in 2008. We aggregated the data to the hospital referral region level and used small area analysis techniques to generate descriptive statistics. We mapped geographic variations in chiropractic supply, use and utilization intensity (treatments per user), and quantified the variation by coefficient of variation and extremal ratio. We used Spearman rank correlation coefficient to correlate use with supply. We used a logistic regression model for chiropractic use and a multiple linear regression model for chiropractic utilization intensity. RESULTS: The average regional supply of chiropractic physicians was 21.5 per 100,000 adult capita. The average percentage of beneficiaries who used chiropractic was approximately 7.6 (SD, 3.9). The average utilization intensity was 10.6 (SD, 1.8). Regional chiropractic supply varied more than 14-fold, and chiropractic use varied more than 17-fold. Chiropractic supply and use were positively correlated (Spearman ρ, 0.68; P < 0.001). A low back or cervical spine problem was strongly associated with chiropractic use (odds ratios, 21.6 and 14.3, respectively). Increased chiropractic supply was associated with increased chiropractic use (odds ratio, 1.04) but not with increased chiropractic utilization intensity. CONCLUSION: Both the supply of chiropractors and the utilization of chiropractic by older US adults varied widely by region. Increased chiropractic supply was associated with increased chiropractic use but not with increased chiropractic utilization intensity. Utilization of chiropractic care is likely sensitive to both supply and patient preference.

Growth in the use of PET for six cancer types after coverage by medicare: additive or replacement?

BACKGROUND: In July 2001, PET became a covered service for Medicare beneficiaries when used for the diagnosis, staging, and restaging of non-small-cell lung, esophageal, colorectal, and head and neck cancers as well as lymphoma and melanoma. Whether physicians use PET as a replacement for or in addition to CT, MRI, or bone scintigraphy (BS) is uncertain. METHODS: A 20% sample of Medicare fee-for-service beneficiaries aged > 64 years from 2004 through 2008 was used. Annually for each cancer type, a cohort of patients was created defined as having at least one admission with a primary cancer diagnosis or two nonhospital claims with a cancer diagnosis ≥7 days apart per calendar year. Each year, imaging claims and claim-days were counted by modality and cancer type. The sequence of PET use was examined as before, after, or instead of other imaging. RESULTS: About 125,000 beneficiaries (2.5% of the cohort) met the cancer definition each year. In 2008, the combined annual imaging days per person-year were 2.3 for CT, 0.49 for MRI, 0.70 for PET, and 0.13 for BS. The annual rates of imaging from 2004 to 2008 increased by 0.5% for CT, 3.2% for MRI, and 18.0% for PET (range, 14.6%-19.9% by cancer type) and decreased by 12.7% for BS. The growth in PET use was not associated with meaningful changes in body CT. In 2007 and 2008, body CT preceded PET within 30 days in about half of patients, whereas PET preceded CT in only 22%. CONCLUSIONS: Several years after its introduction, PET continued to grow rapidly, with evidence that it is replacing BS. Growth of PET occurred without evidence of a decline in body CT. About half of PET use occurred shortly after body CT, suggesting an additive or final arbiter role.

Geographic variations in availability and use of chiropractic under medicare.

OBJECTIVE: The purpose of this study was to measure geographic variations in the availability and use of chiropractic under Medicare. METHODS: A cross-sectional design was used to analyze a large nationally representative sample of Medicare data. Data from a 20% representative sample of all paid Medicare Part B fee-for-service claims for 2007 were merged with files containing beneficiary and provider data. The sample was restricted to adults aged 65 to 99 years. Measures of chiropractic availability and use were described and selectively mapped by state. Geographic variations were quantified. Spearman test was used to evaluate for correlation between chiropractic availability and use. RESULTS: The average number of doctors of chiropractic (DC) by state was 1135; average DC per 1000 beneficiaries was 2.5 (SD, 1.1). The average number of chiropractic users by state was 34,502 (SD, 30,844); average chiropractic users per 1000 beneficiaries was 76 (SD, 41). Chiropractic availability by state varied 6-fold, and chiropractic use varied nearly 30-fold. Availability was strongly correlated with use (Spearman ρ, 0.86; P < .001). Expenditures per DC were highest in the upper Midwest and lowest in the far West; expenditures per user were highest in New England and New York, and lowest in the West. CONCLUSION: Chiropractic availability and use by older adults under Medicare predominated in rural states in the North Central United States. Expenditures were higher in the East and Midwest and lower in the far West. Chiropractic availability and use by state were highly correlated. Future analyses should use small-area analysis and statistical modeling to identify factors predictive of chiropractic use.

Measuring racial disparities in the quality of ambulatory diabetes care.

BACKGROUND: Improving the health of minority patients who have diabetes depends in part on improving quality and reducing disparities in ambulatory care. It has been difficult to measure these components at the level of actionable units. OBJECTIVE: To measure ambulatory care quality and racial disparities in diabetes care across groups of physicians who care for populations of ambulatory diabetes patients. RESEARCH DESIGN: Prospective cohort analysis using administrative data. SUBJECTS: Using fee-for-service Medicare claims data from 2003 to 2005, we link patients to their principal ambulatory care physician. The patients are then linked to the hospital where their physicians work or have their patients admitted, creating physician-hospital networks. MEASURES: Proportion of recommended diabetes testing received by black and nonblack diabetes patients. RESULTS: Blacks received 70% of recommended care compared with nonblacks who received 76.9% (P < 0.001). However, for black and nonblack patients, variation in the quality of care exceeds the racial gap in treatment. The network-specific performance rates for blacks and nonblacks were highly correlated (r = 0.67, P < 0.001), but 47% of blacks, versus 31% of nonblacks, received care from the third of networks with lowest quality. Physician-hospital networks with higher overall quality, or patients with higher socioeconomic status, were no less likely to exhibit black-white disparities. CONCLUSIONS: It is possible to measure, benchmark, and monitor the quality of minority care at the level of networks responsible for ambulatory care. Consequently, it should be easier to provide patients with information on network performance and to design policies that improve the quality of minority-serving providers.

Regional variations in diagnostic practices.

BACKGROUND: Current methods of risk adjustment rely on diagnoses recorded in clinical and administrative records. Differences among providers in diagnostic practices could lead to bias. METHODS: We used Medicare claims data from 1999 through 2006 to measure trends in diagnostic practices for Medicare beneficiaries. Regions were grouped into five quintiles according to the intensity of hospital and physician services that beneficiaries in the region received. We compared trends with respect to diagnoses, laboratory testing, imaging, and the assignment of Hierarchical Condition Categories (HCCs) among beneficiaries who moved to regions with a higher or lower intensity of practice. RESULTS: Beneficiaries within each quintile who moved during the study period to regions with a higher or lower intensity of practice had similar numbers of diagnoses and similar HCC risk scores (as derived from HCC coding algorithms) before their move. The number of diagnoses and the HCC measures increased as the cohort aged, but they increased to a greater extent among beneficiaries who moved to regions with a higher intensity of practice than among those who moved to regions with the same or lower intensity of practice. For example, among beneficiaries who lived initially in regions in the lowest quintile, there was a greater increase in the average number of diagnoses among those who moved to regions in a higher quintile than among those who moved to regions within the lowest quintile (increase of 100.8%; 95% confidence interval [CI], 89.6 to 112.1; vs. increase of 61.7%; 95% CI, 55.8 to 67.4). Moving to each higher quintile of intensity was associated with an additional 5.9% increase (95% CI, 5.2 to 6.7) in HCC scores, and results were similar with respect to laboratory testing and imaging. CONCLUSIONS: Substantial differences in diagnostic practices that are unlikely to be related to patient characteristics are observed across U.S. regions. The use of clinical or claims-based diagnoses in risk adjustment may introduce important biases in comparative-effectiveness studies, public reporting, and payment reforms.

Variation in prostate-specific antigen screening in men aged 80 and older in fee-for-service Medicare.

OBJECTIVES: To determine the rate of prostate-specific antigen (PSA) screening in men aged 80 and older in Medicare and to examine geographic variation in screening rates across the U.S. DESIGN: Retrospective cohort study of variation across hospital referral regions using administrative data. SETTING: National random sample in fee-for-service Medicare. PARTICIPANTS: Medicare beneficiaries aged 80 and older in 2003. MEASUREMENTS: Percentage of men aged 80 and older screened using the PSA test. RESULTS: The national rate of PSA screening in men aged 80 and older was 17.2%, but there was wide variation across regions (<2-38%). Higher PSA screening in a region was positively associated with greater total costs (correlation coefficient (r)=0.49, P<.001), greater intensive care unit use at the end of life (r=0.46, P<.001), and greater number of unique physicians seen (r=0.36, P<.001). PSA screening was negatively associated with proportion of beneficiaries using a primary care physician as opposed to a medical subspecialist for the predominance of ambulatory care (r=-0.38, P<.001). CONCLUSION: PSA screening in men aged 80 and older is common practice, although its frequency is highly variable across the United States. Its association with fragmented physician care and aggressive end-of-life care may reflect less reliance on primary care and consequent difficulty informing patients of the potential harms and low likelihood of benefit of this procedure.

Prices don't drive regional Medicare spending variations.

Per capita Medicare spending is more than twice as high in New York City and Miami than in places like Salem, Oregon. How much of these differences can be explained by Medicare's paying more to compensate for the higher cost of goods and services in such areas? To answer this question, we analyzed Medicare spending after adjusting for local price differences in 306 Hospital Referral Regions. The price-adjustment analysis resulted in less variation in what Medicare pays regionally, but not much. The findings suggest that utilization-not local price differences-drives Medicare regional payment variations, along with special payments for medical education and care for the poor.

Cancer care in the United States: identifying end-of-life cohorts.

OBJECTIVES: End-of-life care is increasingly recognized as an important part of cancer management for many patients. Current methods to measure end-of-life care are limited by difficulties in identifying cancer cohorts with administrative data. We examined several techniques of identifying end-of-life cancer cohorts with claims data that is population-based, geographically scalable, and amenable to routine updating. METHODS: Using Medicare claims for patients 65 years of age and older, four techniques for identifying end-of-life cancer cohorts were compared; one based on Part A data using a broad primary or narrow secondary diagnosis of cancer, two based on Part B data, and one combining the Part A and B methods. We tested the performance of each definition to ascertain an appropriate end-of-life cancer population. RESULTS: The combined Part A and B definition using a primary or secondary diagnosis of cancer within a window of 180 days prior to death appears to be the most accurate and inclusive in ascertaining an end-of-life cohort (78.7% attainment). CONCLUSION: Combining inpatient and outpatient claims data, and identifying cases based upon a broad primary or a narrow secondary cancer definition is the most accurate and inclusive in ascertaining an end-of-life cohort.

Barriers to care among American Indians in public health care programs.

OBJECTIVE: We sought to examine the extent to which reported barriers to health care services differ between American Indians (AIs) and non-Hispanic Whites (Whites). METHODS: A statewide stratified random sample of Minnesota health care program enrollees was surveyed. Responses from AI and White adult enrollees (n=1281) and parents of child enrollees (n=572) were analyzed using logistic regression models that account for the complex sample design. Barriers examined include: financial, access, and cultural barriers, confidence/trust in providers, and discrimination. RESULTS: Both AIs and Whites report barriers to health care access. However, a greater proportion of AIs report barriers in most categories. Among adults, AIs are more likely to report racial discrimination, cultural misunderstandings, family/work responsibilities, and transportation difficulties, whereas Whites are more likely to report being unable to see their preferred doctor. A higher proportion of adult enrollees compared with parents of child enrollees report barriers in most categories; however, differences between parents of AIs and White children are more substantial. In addition to racial discrimination and cultural misunderstandings, parents of AI children are more likely than parents of White enrollees to report limited clinic hours, lack of respect for religious beliefs, and mistrust of their child's provider as barriers. CONCLUSIONS: Although individuals have enrolled in health care programs and have access to care, barriers to using these services remain. Significant differences between AIs and Whites involve issues of trust, respect, and discrimination. Providers must address barriers experienced by AIs to improve accessibility, acceptability, and quality of care for AI health care consumers.