The diffusion of health care fraud: A bipartite network analysis.

Many studies have examined the diffusion of health care innovation but less is known about the diffusion of health care fraud. In this paper, we consider the diffusion of potentially fraudulent Medicare home health care billing in the United States during 2002-16, with a focus on the 21 hospital referral regions (HRRs) covered by local Department of Justice (DOJ) anti-fraud "strike force" offices. We hypothesize that patient-sharing across home health care agencies (HHAs) provides a mechanism for the rapid diffusion of fraudulent strategies. We measure such activity using a novel bipartite mixture (or BMIX) network index, which captures patient sharing across multiple agencies and thus conveys more information about the diffusion process than conventional unipartite network measures. Using a complete population of fee-for-service Medicare claims data, we first find a remarkable increase in home health care activity between 2002 and 2009 in many regions targeted by the DOJ; average billing per Medicare enrollee in McAllen TX and Miami increased by $2127 and $2422 compared to just an average $289 increase in other HRRs not targeted by the DOJ. Second, we establish that the HRR-level BMIX (but not other network measures) was a strong predictor of above-average home health care expenditures across HRRs. Third, within HRRs, agencies sharing more patients with other agencies were predicted to increase billing. Finally, the initial 2002 BMIX index was a strong predictor of subsequent changes in HRR-level home health billing during 2002-9. These results highlight the importance of bipartite network structure in diffusion and in infection and contagion models more generally.

Who will need long-term care? Creation and validation of an instrument that identifies older people at risk.

The aim of this study was to create and measure the predictive validity of a screening instrument that identifies older people who are at risk for developing a need for long-term care within a year. This was an observational study, with participants allocated to either a derivation cohort or a validation cohort, in the United States. A nationally representative sample of older community-dwelling Medicare beneficiaries (n = 6,538) participated in the Medicare Current Beneficiary Survey. Questions addressed sociodemographic, functional, health-related, and utilization characteristics in 1991 and 1992, linked to records of Medicare payments for health services during 1991-1992. In the derivation cohort, 14 self-reported characteristics were significant predictors of developing a need for long-term care within 1 year. In the validation cohort, these 14 characteristics identified a high-risk subgroup (18%) that, during the following year, developed a need for long-term care at six times the rate of the low-risk majority. This brief survey instrument identifies a high-risk minority of older people that will, during the following year, develop a need for long-term care at six times the rate of the low-risk majority. This instrument may be useful for targeting at-risk subgroups of older populations to receive interventions designed to preserve functional independence and avert the need for long-term care.

Use of Medicare services by elderly residents of Puerto Rico.

OBJECTIVES: We describe hospitalization rates among Medicare beneficiaries resident in Puerto Rico compared to beneficiaries in the mainland U.S., in 1999. METHODS: A cross-sectional analysis using Medicare Denominator and hospitalization files. RESULTS: The rate ratio (PR/U.S.) of age, gender-adjusted hospitalizations among elderly Medicare beneficiaries with Part A coverage was 0.78, compared with 0.92 among beneficiaries with both Part A and Part B coverage. Among the latter, the rate ratios were 0.78 for surgical admissions, 1.08 for low-variation medical conditions, and 0.97 for high variation medical conditions. They were higher for younger elderly beneficiaries. CONCLUSIONS: Rates of hospitalization in Puerto Rico may be lower, the same or exceed those of the mainland U.S. depending on the age of the beneficiary and the type of hospitalization.

Local population characteristics and hemoglobin A1c testing rates among diabetic medicare beneficiaries.

BACKGROUND: Proposed payment reforms in the US healthcare system would hold providers accountable for the care delivered to an assigned patient population. Annual hemoglobin A1c (HbA1c) tests are recommended for all diabetics, but some patient populations may face barriers to high quality healthcare that are beyond providers' control. The magnitude of fine-grained variations in care for diabetic Medicare beneficiaries, and their associations with local population characteristics, are unknown. METHODS: HbA1c tests were recorded for 480,745 diabetic Medicare beneficiaries. Spatial analysis was used to create ZIP code-level estimated testing rates. Associations of testing rates with local population characteristics that are outside the control of providers--population density, the percent African American, with less than a high school education, or living in poverty--were assessed. RESULTS: In 2009, 83.3% of diabetic Medicare beneficiaries received HbA1c tests. Estimated ZIP code-level rates ranged from 71.0% in the lowest decile to 93.1% in the highest. With each 10% increase in the percent of the population that was African American, associated HbA1c testing rates were 0.24% lower (95% CI -0.32--0.17); for identical increases in the percent with less than a high school education or the percent living in poverty, testing rates were 0.70% lower (-0.95--0.46) and 1.6% lower (-1.8--1.4), respectively. Testing rates were lowest in the least and most densely populated ZIP codes. Population characteristics explained 5% of testing rate variations. CONCLUSIONS: HbA1c testing rates are associated with population characteristics, but these characteristics fail to explain the vast majority of variations. Consequently, even complete risk-adjustment may have little impact on some process of care quality measures; much of the ZIP code-related variations in testing rates likely result from provider-based differences and idiosyncratic local factors not related to poverty, education, or race.

Accountability for end-stage organ care: implications of geographic variation in access to kidney transplantation.

BACKGROUND: The provision of effective surgical care for end-stage renal disease (ESRD) requires efficient evaluation and transplantation. Prior assessments of transplant access have focused primarily on waitlisted patients rather than the overall populations served by "accountable" providers of transplant services. METHODS: Novel transplant referral regions (TRRs) were defined using United Network for Organ Sharing registry data for 301,092 kidney transplant listings to assign zip codes to "accountable" transplant programs. Subsequently, risk-adjusted observed to expected (O:E) rates of listing and transplant procedures were calculated for each TRR. Finally, the impact of variation in TRR listing and transplant rates on mortality was assessed for ESRD patients <60 years old diagnosed between 2000 and 2008. RESULTS: In total, 113 TRRs were defined, 51% of which included >1 transplant center. The likelihood of being evaluated and listed for transplant varied significantly between TRRs (risk-adjusted O:E, 0.58-1.95). Variation was greater for the overall transplant rate (0.62-2.19), living donor transplantation (0.36-3.08), and donation after cardiac death transplant (0-15.4) than for standard criteria donors (0.64-2.86). Mortality was decreased for ESRD patients living in TRRs in the highest tertile of listings (hazard ratio, 0.89; P < .0001) and transplantation (0.90; P < .0001). CONCLUSION: Residence in a TRR with care delivery systems that increase access to transplant services is associated with significant, risk-adjusted decreases in ESRD-related mortality. Transplant centers should continue to focus on improving access to care within the communities they serve.

State spending on dual eligibles under age 65 shows variations, evidence of cost shifting from Medicaid to Medicare.

Roughly half of Medicare beneficiaries under age sixty-five are also eligible for Medicaid. These "dual eligibles" have been the subject of much research because of their low income and poor health status. Previous studies suggest that some states seek to shift costly health care services for this group out of state-run Medicaid programs and into the federally funded Medicare program--for example, replacing nursing home care with hospital care. Using state-level data on dual eligibles under age sixty-five, we found support for this hypothesis. In states with below-average per capita Medicaid spending, corresponding Medicare spending was above average. These state-level estimates also revealed a nearly threefold difference in total--Medicare plus Medicaid-price--adjusted spending per person, ranging from $16,309 in Georgia to $43,587 in New York. Such large variations among people with serious diseases suggest inefficiency. Some states may be spending too little for Medicaid, meaning that some patients' needs are not being met, or some states may be spending too much, meaning that more services are being provided than needed. Such inefficiency exposes patients to unnecessary risk, drives costs up unnecessarily, and highlights the large potential gains arising from improved care coordination for dual eligibles.

Prostate biopsies in men with limited life expectancy.

CONTEXT: Authorities discourage prostate screening in men who are likely to die from causes other than prostate cancer. PRACTICE PATTERN EXAMINED: Use of prostate biopsy-a proxy for screening-in men aged 65 and older with limited life expectancy (i.e., estimated to be less than 10 years). DATA SOURCE: Five percent samples of Part A (hospital) and Part B (physician) Medicare claims for 1993 through 1997. RESULTS: 22% of all Medicare beneficiaries who underwent a prostate biopsy had a limited life expectancy, corresponding to a rate of 1420 biopsies per 100,000. This rate did not change significantly between 1993 and 1997. For men with a life expectancy greater than 10 years, the biopsy rate was 2,360 per 100,000. Among men with limited life expectancy, in the year following the biopsy, 1.6% had radical prostatectomy and 2.3% had external-beam radiation. Thirty-nine percent were hospitalized. CONCLUSION: A substantial proportion of prostate biopsies are being performed in men with a life expectancy of less than 10 years. These men are unlikely to benefit from the biopsy or subsequent treatment.

The Quality of Medical Care in the United States: A Report on the Medicare Program: the Dartmouth Atlas of Health Care 1999

The United States leads the world, by a substantial measure, in its monetary commitment to medical care. If, as we have long believed, more care is better care, then American medicine must surely be the best in the world. But where is the "best" of American medicine? Previous editions of the Atlas have demonstrated conclusively that in American health care, geography is destiny. Both the amounts and kinds of care provided to residents of the United States are highly dependent on two factors: the capacity of the local health care system (which influences how much care is provided) and the practice style of local physicians (which determines what kind of care is provided). Variations in the intensity of use of hospitals, the striking differences in care at the end of life, and the nearly random patterns of elective surgery all raise questions about the outcomes and value of care­about quality. Is more in fact better? What is the value received for the money spent? What, as Joseph Juran asked, is the cost of poor quality? These questions are receiving increasing public attention. The National Academy of Sciences convened the National Roundtable on Health Care Quality to assess the problem of quality of care. Reporting its findings in the American Journal of Medicine, the Roundtable concluded: "Serious and widespread quality problems exist throughout American medicine. These problems, which may be classified as underuse, overuse and misuse, occur in small and large communities alike, in all parts of the country and with approximately equal frequency in managed care and fee-for-service systems of care." The Roundtable estimated that "very large numbers of Americans are harmed as a direct result" of poor quality care: "Millions of Americans are not reached by proven effective interventions that can save lives and prevent disability. Perhaps an equal number suffer needlessly because they are exposed to the harms of unnecessary health services. Large numbers are injured because preventable complications are not averted." The concern about quality is not restricted to experts or to those who speak on the part of patients or the American public. Ordinary citizens are concerned. The American Hospital Association's "Reality✓" investigation revealed that patients have significant problems with "The way the 'system' works (or fails to work), and the way decisions are made about their care." Patients interviewed by the Picker Institute for this study reported that they "see a confusing, expensive, unreliable and often impersonal dis-assembly of medical professionals and institutions." Moreover, patients expressed a strong concern over their own roles in making health care decisions. Asked who should control decisions about health care in an "ideal world," AHA focus group participants answered that they, themselves, should call the shots, along with their doctors. Patients are more aware than they have been in the past about the variations and alternatives in treatments for many disorders, and they are more likely to question doctors about decisions regarding their treatment ... [a] senior citizen who had recently drawn up a living will with the help of her seniors' group commented, "I didn't know before that I could refuse! Now I know!" These findings call into question the underlying assumption that more care is better care, and that access and cost are the most fundamental problems of the American health care system. Patients as well as health services researchers have begun to ask whether more really is better, and whether the "system" really is a system. Until we can answer those questions with any certainty, we will not be able to achieve real quality in American medical care.