The Medical Costs of Determining Eligibility and Waiting for a Kidney Transplantation.

BACKGROUND: Recent efforts to increase access to kidney transplant (KTx) in the United States include increasing referrals to transplant programs, leading to more pretransplant services. Transplant programs reconcile the costs of these services through the Organ Acquisition Cost Center (OACC). OBJECTIVE: The aim of this study was to determine the costs associated with pretransplant services by applying microeconomic methods to OACC costs reported by transplant hospitals. RESEARCH DESIGN, SUBJECTS, AND MEASURES: For all US adult kidney transplant hospitals from 2013 through 2018 (n=193), we crosslinked the total OACC costs (at the hospital-fiscal year level) to proxy measures of volumes of pretransplant services. We used a multiple-output cost function, regressing total OACC costs against proxy measures for volumes of pretransplant services and adjusting for patient characteristics, to calculate the marginal cost of each pretransplant service. RESULTS: Over 1015 adult hospital-years, median OACC costs attributable to the pretransplant services were $5 million. Marginal costs for the pretransplant services were: initial transplant evaluation, $9k per waitlist addition; waitlist management, $2k per patient-year on the waitlist; deceased donor offer management, $1k per offer; living donor evaluation, procurement and follow-up: $26k per living donor. Longer time on dialysis among patients added to the waitlist was associated with higher OACC costs at the transplant hospital. CONCLUSIONS: To achieve the policy goals of more access to KTx, sufficient funding is needed to support the increase in volume of pretransplant services. Future studies should assess the relative value of each service and explore ways to enhance efficiency.

Trends and disparities in the utilization of influenza vaccines among commercially insured US adults during the COVID-19 pandemic.

OBJECTIVES: Little is known about how the coronavirus disease 2019 (COVID-19) pandemic affected influenza vaccine utilization and disparities. We sought to estimate changes in the likelihood of receiving an influenza vaccine across different demographic subgroups during the COVID-19 pandemic. METHODS: In this cohort study, we analyzed influenza vaccine uptake from 2019 to 2020 using Optum commercial insurance claims data. Eligible individuals were aged 18 or above in 2018 and continuously enrolled from 08/01/2018 through 12/31/2020. Multivariable logistic regressions were fitted for the individual-level influenza vaccine uptake. Adjusting for demographic factors and medical histories, we estimated probabilities of receiving influenza vaccines before and after the COVID-19 pandemic across demographic subgroups. RESULTS: From August to December 2019, unadjusted influenza vaccination rate was 42.3%, while in the same period of 2020, the vaccination rate increased to 45.9%. Females had a higher vaccination rate in 2019 (OR: 1.16, 95% CI 1.15-1.16), but the increase was larger for males. Blacks and Hispanics had lower vaccination rates relative to whites in both flu seasons. Hispanics showed a greater increase in vaccination rate, increasing by 7.8 percentage points (p < .001) compared to 4.4 (p < .001) for whites. The vaccination rate for Blacks increased by 5.2 percentage points (p < .001). All income groups experienced vaccination improvements, but poorer individuals had lower vaccination rates in both seasons. The most profound disparities occurred when educational cohort were considered. The vaccination rate increased among college-educated enrollees by 8.8 percentage points (p < .001) during the pandemic compared to an increase of 2.8 percentage points (p < .001) for enrollees with less than a 12th grade education. Past influenza infections or vaccination increased the likelihood of vaccination (p < .001). CONCLUSIONS: The COVID-19 pandemic was associated with increased influenza vaccine utilization. Disparities persisted but narrowed with respect to gender and race but worsened with respect to income and educational attainment.

The impact of Facebook's vaccine misinformation policy on user endorsements of vaccine content: An interrupted time series analysis.

OBJECTIVES: To evaluate the impact of Facebook's vaccine misinformation policy in March 2019 on user endorsements of vaccine content on its platform. METHODS: We identified 172 anti- and pro-vaccine Facebook Pages and collected posts from these Pages six months before and after the policy. Using interrupted time series regression models, we evaluated the policy impact on user endorsements (i.e., likes) of anti- and pro-vaccine posts on Facebook. RESULTS: The number of likes for posts on anti-vaccine Pages had decreased after the policy implementation (policy = 153.2, p < 0.05; policy*day = -0.838, p < 0.05; marginal effect at the mean = -22.74, p < 0.01; marginal effect at the median = -24.56, p < 0.01). When the number of subscribers was considered, the policy effect on the number of likes for anti-vaccine posts was much smaller, but still statistically significant (policy = 4.849, p < 0.05; policy*day = -0.027, p < 0.05; marginal effect at the mean = -0.742, p < 0.01; marginal effect at the median = -0.800, p < 0.01). There was no policy effect observed for posts on pro-vaccine Pages. CONCLUSIONS: Our analysis suggested that Facebook's March 2019 vaccine misinformation policy moderately impacted the number of endorsements of anti-vaccine content on its platform. Social media companies can take measures to limit the popularity of anti-vaccine content by reducing their reach and visibility. Future research efforts should focus on evaluating additional policies and examining policies across platforms.

Trends in Cost Attributable to Kidney Transplantation Evaluation and Waiting List Management in the United States, 2012-2017.

Importance: While recent policy reforms aim to improve access to kidney transplantation for patients with end-stage kidney disease, the cost implications of kidney waiting list expansion are not well understood. The Organ Acquisition Cost Center (OACC) is the mechanism by which Medicare reimburses kidney transplantation programs, at cost, for costs attributable to kidney transplantation evaluation and waiting list management, but these costs have not been well described to date. Objectives: To describe temporal trends in mean OACC costs per kidney transplantation and to identify factors most associated with cost. Design, Setting, and Participants: This economic evaluation included all kidney transplantation waiting list candidates and recipients in the United States from 2012 to 2017. A population-based study of cost center reports was conducted using data from all Center of Medicare & Medicaid-certified transplantation hospitals. Data analysis was conducted from June to August 2021. Exposures: Year, local price index, transplantation and waiting list volume of transplantation program, and comorbidity burden. Main Outcomes and Measures: Mean OACC costs per kidney transplantation. Results: In 1335 hospital-years from 2012 through 2017, Medicare's share of OACC costs increased from $0.95 billion in 2012 to $1.32 billion in 2017 (3.7% of total Medicare End-Stage Renal Disease program expenditure). Median (IQR) OACC costs per transplantation increased from $81 000 ($66 000 to $103 000) in 2012 to $100 000 ($82 000 to $125 000) in 2017. Kidney organ procurement costs contributed to 36% of mean OACC costs per transplantation throughout the study period. During the study period, transplantation hospitals experienced increases in kidney waiting list volume, kidney waiting list active volume, kidney transplantation volume, and comorbidity burden. For a median-sized transplantation program, mean OACC costs per transplantation decreased with more transplants (-$3500 [95% CI, -$4300 to -$2700] per 10 transplants; P < .001) and increased with year ($4400 [95% CI, $3500 to $5300] per year; P < .001), local price index ($1900 [95% CI, $200 to $3700] per 10-point increase; P = .03), patients listed active on the waiting list ($3100 [95% CI, $1700 to $4600] per 100 patients; P < .001), and patients on the waiting list with high comorbidities ($1500 [9% CI, $600 to $2500] per 1% increase in proportion of waitlisted patients with the highest comorbidity score; P = .002). Conclusions and Relevance: In this study, OACC costs increased at 4% per year from 2012 to 2017 and were not solely attributable to the cost of organ procurement. Expanding the waiting list will likely contribute to further increases in the mean OACC costs per transplantation and substantially increase Medicare liability.

Financial impacts of the Medicaid expansion on community health centers.

OBJECTIVE: To determine the impacts of the Medicaid expansion on revenues, costs, assets, and liabilities of federally funded community health centers. DATA SOURCES: We combined data from the Uniform Data System, Internal Revenue Service nonprofit tax returns, and county-level characteristics from the Census Bureau. Our final dataset included 5841 center-year observations. STUDY DESIGN: We used difference-in-differences model to estimate the fiscal impacts of the Medicaid expansion on community health centers. We employed event study models, state-specific trend models, and placebo law tests as robustness checks. DATA COLLECTION METHODS: Not applicable. PRINCIPAL FINDINGS: On the revenue side, we found a $2.08 million relative increase (p = 0.002) in Medicaid revenues, offset by a $0.44 million decrease (p = 0.015) in total grants among community health centers in expansion states compared with centers in non-expansion states. On the expenditure side, we found a large but not statistically significant $0.98 million relative increase (p = 0.201) in total expenditures among centers in expansion states. Uncompensated care for health centers in expansion states decreased by $1.19 million (p < 0.001) relative to their counterparts in non-expansion states. CONCLUSIONS: Community health centers in expansion states benefited from the increased, stable revenue stream from Medicaid expansions. While Medicaid revenue increased as a result of the policy, we find no major evidence of substitution away from other revenue lines, with one notable exception (i.e., substitution away from state and local government grants). From a policy perspective, these results are encouraging as the Biden Administration starts to implement the safety-net enhancements from the American Rescue Plan Act of 2021 and as more non-expansion states are considering opting into Medicaid expansions. It is anticipated that these added revenue streams will help to sustain health centers in the delivery of health care services to the underserved population.

Quality and Cost in Community Health Centers.

BACKGROUND: Quantifying health care quality has long presented a challenge to identifying the relationship between provider level quality and cost. However, growing focus on quality improvement has led to greater interest in organizational performance, prompting payers to collect various indicators of quality that can be combined at the provider level. OBJECTIVE: To explore the relationship between quality and average cost of medical visits provided in US Community Health Centers (CHCs) using composite measures of quality. RESEARCH DESIGN: Using the Uniform Data System collected by the Bureau of Primary Care, we constructed composite measures by combining 9 process and 2 outcome indicators of primary care quality provided in 1331 US CHCs during 2015-2018. We explored different weighting schemes and different combinations of individual quality indicators constructed at the intermediate domain levels of chronic condition control, screening, and medication management. We used generalized linear modeling to regress average cost of a medical visit on composite quality measures, controlling for patient and health center factors. We examined the sensitivity of results to different weighting schemes and to combining individual quality indicators at the overall level compared with the intermediate domain level. RESULTS: Both overall and domain level composites performed well in the estimations. Average cost of a medical visit was negatively associated with quality, although the magnitude of the effect varied across weighting schemes. CONCLUSION: Efforts toward improvement of primary health care quality delivered in CHCs need not involve greater cost.

The organ procurement costs of expanding deceased donor organ acceptance criteria: Evidence from a cost function model.

A potential solution to the deceased donor organ shortage is to expand donor acceptability criteria. The procurement cost implications of using nonstandard donors is unknown. Using 5 years of US organ procurement organization (OPO) data, we built a cost function model to make cost projections: the total cost was the dependent variable; production outputs, including the number of donors and organs procured, were the independent variables. In the model, procuring one kidney or procuring both kidneys from double/en bloc transplantation from a single-organ donor resulted in a marginal cost of $55 k (95% confidence interval [CI] $28 k, $99 k) per kidney, and procuring only the liver from a single-organ donor results in a marginal cost of $41 k (95% CI $12 k, $69 k) per liver. Procuring two kidneys for two candidates from a donor lowered the marginal cost to $36 k (95% CI $22 k, $66 k) per kidney, and procuring two kidneys and a liver lowers the marginal cost to $24 k (95% CI $17 k, $45 k) per organ. Economies of scale were observed, where high OPO volume was correlated with lower costs. Despite higher cost per organ than for standard donors, kidney transplantation from nonstandard donors remained cost-effective based on contemporary US data.

The Impact of Nursing Staff on Satisfaction Scores for U.S. Hospitals: A Production Function Approach.

Hospitals have increasingly relied on nurse assistants to support nurses in the provision of patient care, yet knowledge about their contributions to the patient experience in U.S. hospitals is limited. We address this issue by exploring the impact of nurse assistants and registered nurses on an array of patient satisfaction measures from the Medicare Hospital Consumer Assessment of Healthcare Providers and Systems. Using linked data for 2,807 hospitals from 2008 to 2016, we employ a production function approach to estimate and plot marginal impact curves for both nurse assistants and registered nurses. We find that although registered nurses are more impactful, nurse assistants are the more underdeployed staffing category. We also find that after meeting certain thresholds for minimal hours, nurse assistants have a comparative advantage in improving patient satisfaction scores in the housekeeping and patient support domain. Given their lower labor costs, further employment of nurse assistants may be warranted.

Immunization and Moral Hazard: The HPV Vaccine and Uptake of Cancer Screening.

Immunization can lead to moral hazard by reducing the cost of risky behaviors and reducing preventive efforts. In this study, we examine the effect of HPV (human papillomavirus) vaccination on participation in the Pap test, which is a diagnostic screening test to detect HPV and non-HPV-related cancerous processes. The HPV vaccination is explicitly recommended for women up to age 26 years who were not previously vaccinated. Pap tests are strongly recommended for women between 21 and 65 years old even after having the HPV vaccine. To study the effect of HPV vaccination on Pap test uptake, we construct a fuzzy regression discontinuity design, centered on the vaccination threshold age. The results suggest that moral hazard was not the dominant effect. The estimates show that women who have been vaccinated, if anything, are actually more likely to have a Pap test, possibly due to increased awareness of its benefits at the time of vaccination.

Optimal staffing in community health centers to improve quality of care.

OBJECTIVE: To explore optimal workforce configurations in the production of care quality in community health centers (CHCs), accounting for interactions among occupational categories, as well as contributions to the volume of services. DATA SOURCES: We linked the Uniform Data System from 2014 to 2016 with Internal Revenue Service nonprofit tax return data. The final database contained 3139 center-year observations from 1178 CHCs. STUDY DESIGN: We estimated a system of two generalized linear production functions, with quality of care and volume of services as outputs, using the average percent of diabetic patients with controlled A1C level and hypertensive patients with controlled blood pressure as quality measures. To explore the substitutability and complementarity between staffing categories, we estimated a revenue function. FINDINGS: Primary care physicians and advanced practice clinicians achieve similar quality outcomes (3.2 percent and 3.0 percent improvement in chronic condition management per full-time equivalent (FTE), respectively). Advanced practice clinicians generate less revenue per FTE but are generally less costly to employ. CONCLUSION: As quality incentives are further integrated into payment systems, CHCs will need to optimize their workforce configuration to improve quality. Given the relative efficiency of advanced practice clinicians in producing quality, further hiring of these professionals is a cost-effective investment for CHCs.

Hospital Response to CMS Public Reports of Hospital Charge Information.

BACKGROUND: In an effort to increase price transparency, the Centers for Medicare and Medicaid Services (CMS) began reporting charges for Medicare inpatients treated in ∼3400 hospitals online in 2013. As of 2019, CMS began to require hospitals themselves to publicize a more comprehensive list of their underlying procedure charges. OBJECTIVE: The objective of this study was to assess the responses of hospitals to broad-scale public reporting of their charges for inpatient services. RESEARCH DESIGN: We used descriptive analysis to examine the trend in CMS charge data for high charge hospitals before and after the 2013 intervention. We also applied difference-in-differences analysis to comprehensive inpatient charge data from New York and Florida for the years 2011-2016, defining the reported high-volume diagnosis-related groups (DRGs) as the intervention group. RESULTS: At the national level, the CMS charge data showed relatively lower growth in high charge hospitals following the intervention. From the state data, we found that after 3 years, the growth in charges for reported DRGs in New York hospitals was 4%-9% lower than for unreported diagnosis-related groups. In Florida, it was 2%-8% lower. CONCLUSION: Public reports of hospital inpatient charges by DRG appear to influence subsequent charges, slowing their growth.

Do All Hospital Systems Have Market Power? Association Between Hospital System Types and Cardiac Surgery Prices.

OBJECTIVE: This study explores the price implications of hospital systems by analyzing the association of system characteristics with selected cardiac surgery pricing. DATA SOURCE: Using a large private insurance claim database, the authors identified 11 282 coronary artery bypass graft (CABG) cases and 49 866 percutaneous coronary intervention (PCI) cases from 2002 to 2007. STUDY DESIGN: We conducted a retrospective observational study using generalized linear models. PRINCIPAL FINDINGS: We found that the CABG and PCI prices in centralized health and physician insurance systems were significantly lower than the prices in stand-alone hospitals by 4.4% and 6.4%, respectively. In addition, the CABG and PCI prices in independent health systems were significantly lower than in stand-alone hospitals, by 15.4% and 14.5%, respectively. CONCLUSION: The current antitrust guidelines tend to focus on the market share of merging parties and pay less attention to the characteristics of merging parties. The results of this study suggest that antitrust analysis could be more effective by considering characteristics of hospital systems.

Association of Medical Liability Reform With Clinician Approach to Coronary Artery Disease Management.

Importance: Physicians often report practicing defensive medicine to reduce malpractice risk, including performing expensive but marginally beneficial tests and procedures. Although there is little evidence that malpractice reform affects overall health care spending, it may influence physician behavior for specific conditions involving clinical uncertainty. Objective: To examine whether reducing malpractice risk is associated with clinical decisions involving coronary artery disease testing and treatment. Design, Setting, and Participants: Difference-in-differences design, comparing physician-specific changes in coronary artery disease testing and treatment in 9 new-cap states that adopted damage caps between 2003 and 2005 with 20 states without caps. We used the 5% national Medicare fee-for-service random sample between 1999 and 2013. Physicians (n = 75 801; 36 647 in new-cap states) who ordered or performed 2 or more coronary angiographies. Data were analyzed from June 2015 to January 2018. Main Outcomes and Measures: Changes in ischemic evaluation rates for possible coronary artery disease, type of initial evaluation (stress testing or coronary angiography), progression from stress test to angiography, and progression from ischemic evaluation to revascularization (percutaneous coronary intervention or coronary artery bypass grafting). Results: We studied 36 647 physicians in new-cap states and 39 154 physicians in no-cap states. New-cap states had younger populations, more minorities, lower per-capita incomes, fewer physicians per capita, and lower managed care penetration. Following cap adoption, new-cap physicians reduced invasive testing (angiography) as a first diagnostic test compared with control physicians (relative change, -24%; 95% CI, -40% to -7%; P = .005) with an offsetting increase in noninvasive stress testing (7.8%; 95% CI, -3.6% to 19.3%; P = .17), and referred fewer patients for angiography following stress testing (-21%; 95% CI, -40% to -2%; P = .03). New-cap physicians also reduced revascularization rates after ischemic evaluation (-23%; 95% CI, -40% to -4%; P = .02; driven by fewer percutaneous coronary interventions). Changes in overall ischemic evaluation rates were similar for new-cap and control physicians (-0.05%; 95% CI, -8.0% to 7.9%; P = .98). Conclusions and Relevance: Physicians substantially altered their approach to coronary artery disease testing and follow-up after initial ischemic evaluations following adoption of damage caps. They performed a similar number of ischemic evaluations but conducted fewer initial left heart catheterizations, referred fewer stress-tested patients for left heart catheterizations, and referred fewer patients for revascularization. These findings suggest that physicians tolerate greater clinical uncertainty in coronary artery disease testing and treatment if they face lower malpractice risk.

Cost-effectiveness of an Evidence-Based Childhood Asthma Intervention in Real-World Primary Care Settings.

We present an incremental cost-effectiveness analysis of an evidence-based childhood asthma intervention (Community Healthcare for Asthma Management and Prevention of Symptoms [CHAMPS]) to usual management of childhood asthma in community health centers. Data used in the analysis include household surveys, Medicaid insurance claims, and community health center expenditure reports. We combined our incremental cost-effectiveness analysis with a difference-in-differences multivariate regression framework. We found that CHAMPS reduced symptom days by 29.75 days per child-year and was cost-effective (incremental cost-effectiveness ratio: $28.76 per symptom-free days). Most of the benefits were due to reductions in direct medical costs. Indirect benefits from increased household productivity were relatively small.

Changes in Case-Mix and Health Outcomes of Medicare Fee-for-Service Beneficiaries and Managed Care Enrollees During the Years 1992-2011.

BACKGROUND: Recent studies suggest that managed care enrollees (MCEs) and fee-for-service beneficiaries (FFSBs) have become similar in case-mix over time; but comparisons of health outcomes have yielded mixed results. OBJECTIVE: To examine changes in differentials between MCEs and FFSBs both in case-mix and health outcomes over time. DESIGN: Temporal study of the linked Health and Retirement Study (HRS) and Medicare data, comparing case-mix and health outcomes between MCEs and FFSBs across 3 time periods: 1992-1998, 1999-2004, and 2005-2011. We used multivariable analysis, stratified by, and pooled across the study periods. The unit of analysis was the person-wave (n=167,204). SUBJECTS: HRS participants who were also enrolled in Medicare. MEASURES: Outcome measures included self-reported fair/poor health, 2-year self-rated worse health, and 2-year mortality. Our main covariate was a composite measure of multimorbidity (MM), MM0-MM3, defined as the co-occurrence of chronic conditions, functional limitations, and/or geriatric syndromes. RESULTS: The case-mix differential between MCEs and FFSBs persisted over time. Results from multivariable models on the pooled data and incorporating interaction terms between managed care status and study period indicated that MCEs and FFSBs were as likely to die within 2 years from the HRS interview (P=0.073). This likelihood remained unchanged across the study periods. However, MCEs were more likely than FFSBs to report fair/poor health in the third study period (change in probability for the interaction term: 0.024, P=0.008), but less likely to rate their health worse in the last 2 years, albeit at borderline significance (change in probability: -0.021, P=0.059). CONCLUSIONS: Despite the persistence of selection bias, the differential in self-reported fair/poor status between MCEs and FFSBs seems to be closing over time.

Multimorbidity: constellations of conditions across subgroups of midlife and older individuals, and related Medicare expenditures.

INTRODUCTION: The Department of Health and Human Services' 2010 Strategic Framework on Multiple Chronic Conditions called for the identification of common constellations of conditions in older adults. OBJECTIVES: To analyze patterns of conditions constituting multimorbidity (CCMM) and expenditures in a US representative sample of midlife and older adults (50-64 and ≥65 years of age, respectively). DESIGN: A cross-sectional study of the 2010 Health and Retirement Study (HRS; n=17,912). The following measures were used: (1) count and combinations of CCMM, including (i) chronic conditions (hypertension, arthritis, heart disease, lung disease, stroke, diabetes, cancer, and psychiatric conditions), (ii) functional limitations (upper body limitations, lower body limitations, strength limitations, limitations in activities of daily living, and limitations in instrumental activities of daily living), and (iii) geriatric syndromes (cognitive impairment, depressive symptoms, incontinence, visual impairment, hearing impairment, severe pain, and dizziness); and (2) annualized 2011 Medicare expenditures for HRS participants who were Medicare fee-for-service beneficiaries (n=5,677). Medicaid beneficiaries were also identified based on their self-reported insurance status. RESULTS: No large representations of participants within specific CCMM categories were observed; however, functional limitations and geriatric syndromes were prominently present with higher CCMM counts. Among fee-for-service Medicare beneficiaries aged 50-64 years, 26.7% of the participants presented with ≥10 CCMM, but incurred 48% of the expenditure. In those aged ≥65 years, these percentages were 16.9% and 34.4%, respectively. CONCLUSION: Functional limitations and geriatric syndromes considerably add to the MM burden in midlife and older adults. This burden is much higher than previously reported.

Cancer preventive services, socioeconomic status, and the Affordable Care Act.

BACKGROUND: Out-of-pocket expenditures are thought to be an important barrier to the receipt of cancer preventive services, especially for those of a lower socioeconomic status (SES). The Affordable Care Act (ACA) eliminated out-of-pocket expenditures for recommended services, including mammography and colonoscopy. The objective of this study was to determine changes in the uptake of mammography and colonoscopy among fee-for-service Medicare beneficiaries before and after ACA implementation. METHODS: Using Medicare claims data, this study identified women who were 70 years old or older and had not undergone mammography in the previous 2 years and men and women who were 70 years old or older, were at increased risk for colorectal cancer, and had not undergone colonoscopy in the past 5 years. The receipt of procedures in the 2-year period before the ACA's implementation (2009-2010) and after its implementation (2011 to September 2012) was also identified. Multivariate generalized estimating equation models were used to determine the independent association and county-level quartile of median income and education with the receipt of testing. RESULTS: For mammography, a lower SES quartile was associated with less uptake, but the post-ACA disparities were smaller than those in the pre-ACA period. In addition, mammography rates increased from the pre-ACA period to the post-ACA period in all SES quartiles. For colonoscopy, in both the pre- and post-ACA periods, there was an association between uptake and educational level and, to some extent, income. However, there were no appreciable changes in colonoscopy and SES after implementation of the ACA. CONCLUSIONS: The removal of out-of-pocket expenditures may overcome a barrier to the receipt of recommended preventive services, but for colonoscopy, other procedural factors may remain as deterrents. Cancer 2017;123:1585-1589. © 2017 American Cancer Society.

The Impact of State Tort Reforms on Imaging Utilization.

PURPOSE: Defensive medicine, broadly defined as medical practices that protect physicians from malpractice lawsuits without providing benefits to patients, can lead to wasteful use of health care resources and higher cost. Although physicians cite malpractice liability as an important factor driving their decisions to order imaging tests, little research has been done to examine the systematic impact of liability pressure on overall imaging. The authors examined the extent to which radiography use is influenced by malpractice liability pressure among office-based physicians. METHODS: Using National Ambulatory Medical Care Survey data from 1999 to 2010, the authors used multivariate difference-in-difference logistic regression to examine the effects of different types of state tort reforms on the probability of radiography orders by primary care physicians (PCPs) and specialists. RESULTS: The probability that a PCP ordered radiography decreased when states enacted permanent caps on noneconomic damages (-1.0%, P < .01), periodic payment reforms (-1.6%, P < .05), and the total number of tort reforms (-0.5%, P < .05). Specialist physicians were responsive to two reforms: caps on punitive damages (-6.1%, P < .01) and the total number of medical tort laws (-1.2%, P < .01). The passage of new indirect reforms was found to reduce radiography orders for PCPs (-1.8%, P < .05), and the repeal of indirect reforms was found to increase radiography orders for specialists (+3.4%, P < .01). CONCLUSIONS: State tort reform seems to reduce physicians' ordering of radiography. This analysis also suggests that reforms that make it harder to sue physicians have a stronger impact than reforms that directly reduce physicians' malpractice claim payments.

Identifying Specific Combinations of Multimorbidity that Contribute to Health Care Resource Utilization: An Analytic Approach.

BACKGROUND: Multimorbidity affects the majority of elderly adults and is associated with higher health costs and utilization, but how specific patterns of morbidity influence resource use is less understood. OBJECTIVE: The objective was to identify specific combinations of chronic conditions, functional limitations, and geriatric syndromes associated with direct medical costs and inpatient utilization. DESIGN: Retrospective cohort study using the Health and Retirement Study (2008-2010) linked to Medicare claims. Analysis used machine-learning techniques: classification and regression trees and random forest. SUBJECTS: A population-based sample of 5771 Medicare-enrolled adults aged 65 and older in the United States. MEASURES: Main covariates: self-reported chronic conditions (measured as none, mild, or severe), geriatric syndromes, and functional limitations. Secondary covariates: demographic, social, economic, behavioral, and health status measures. OUTCOMES: Medicare expenditures in the top quartile and inpatient utilization. RESULTS: Median annual expenditures were $4354, and 41% were hospitalized within 2 years. The tree model shows some notable combinations: 64% of those with self-rated poor health plus activities of daily living and instrumental activities of daily living disabilities had expenditures in the top quartile. Inpatient utilization was highest (70%) in those aged 77-83 with mild to severe heart disease plus mild to severe diabetes. Functional limitations were more important than many chronic diseases in explaining resource use. CONCLUSIONS: The multimorbid population is heterogeneous and there is considerable variation in how specific combinations of morbidity influence resource use. Modeling the conjoint effects of chronic conditions, functional limitations, and geriatric syndromes can advance understanding of groups at greatest risk and inform targeted tailored interventions aimed at cost containment.