Yu-Chu Shen

Characteristics of Occasional and Frequent Emergency Department Users: Do Insurance Coverage and Access to Care Matter?

ObjectiveThe objective of this study was to explore how insurance coverage, access to care, and other individual characteristics are related to the large differences in emergency department (ED) use among the general population. Materials and MethodsWe used the 1997 and 1999 National Survey of America’s Families, a nationally representative sample. People were classified into 3 ED use levels based on the number of visits over the 12 months before the survey: non-ED users (zero visits), occasional users (1 or 2 visits), or frequent users (3 or more visits). We used a multinomial logit model to estimate the effect of insurance status and other factors on levels of ED use, and to compute the odds ratios of being occasional and frequent users as opposed to nonusers among various subpopulations. ResultsPeople in fair/poor health are 3.64 times more likely than others to be frequent ED users as compared with nonusers. The uninsured and the privately insured adults have the same risk of being frequent users, but publicly insured adults are 2.08 times more likely to be frequent users. Adults who made 3 or more visits to doctors are 5.29 times more likely to be frequent ED users than those who made no such visits. ConclusionThe uninsured do not use more ED visits than the insured population as is sometimes argued. Instead, the publicly insured are overrepresented among ED users. Frequent ED users do not appear to use the ED as a substitute for their primary care but, in fact, are a less healthy population who need and use more care overall.

FACTORS ASSOCIATED WITH CLOSURES OF EMERGENCY DEPARTMENTS IN THE UNITED STATES

CONTEXT Between 1998 and 2008, the number of hospital-based emergency departments (EDs) in the United States declined, while the number of ED visits increased, particularly visits by patients who were publicly insured and uninsured. Little is known about the hospital, community, and market factors associated with ED closures. Federal law requiring EDs to treat all in need regardless of a patients ability to pay may make EDs more vulnerable to the market forces that govern US health care. OBJECTIVE To determine hospital, community, and market factors associated with ED closures. DESIGN Emergency department and hospital organizational information from 1990 through 2009 was acquired from the American Hospital Association (AHA) Annual Surveys (annual response rates ranging from 84%-92%) and merged with hospital financial and payer mix information available through 2007 from Medicare hospital cost reports. We evaluated 3 sets of risk factors: hospital characteristics (safety net [as defined by hospitals caring for more than double their Medicaid share of discharges compared with other hospitals within a 15-mile radius], ownership, teaching status, system membership, ED size, case mix), county population demographics (race, poverty, uninsurance, elderly), and market factors (ownership mix, profit margin, location in a competitive market, presence of other EDs). SETTING All general, acute, nonrural, short-stay hospitals in the United States with an operating ED anytime from 1990-2009. MAIN OUTCOME MEASURE Closure of an ED during the study period. RESULTS From 1990 to 2009, the number of hospitals with EDs in nonrural areas declined from 2446 to 1779, with 1041 EDs closing and 374 hospitals opening EDs. Based on analysis of 2814 urban acute-care hospitals, constituting 36,335 hospital-year observations over an 18-year study interval (1990-2007), for-profit hospitals and those with low profit margins were more likely to close than their counterparts (cumulative hazard rate based on bivariate model, 26% vs 16%; hazard ratio [HR], 1.8; 95% confidence interval [CI], 1.5-2.1, and 36% vs 18%; HR, 1.9; 95% CI, 1.6-2.3, respectively). Hospitals in more competitive markets had a significantly higher risk of closing their EDs (34% vs 17%; HR, 1.3; 95% CI, 1.1-1.6), as did safety-net hospitals (10% vs 6%; HR, 1.4; 95% CI, 1.1-1.7) and those serving a higher share of populations in poverty (37% vs 31%; HR, 1.4; 95% CI, 1.1-1.7). CONCLUSION From 1990 to 2009, the number of hospital EDs in nonrural areas declined by 27%, with for-profit ownership, location in a competitive market, safety-net status, and low profit margin associated with increased risk of ED closure.

Association Between Ambulance Diversion and Survival Among Patients With Acute Myocardial Infarction

CONTEXT Ambulance diversion, a practice in which emergency departments (EDs) are temporarily closed to ambulance traffic, might be problematic for patients experiencing time-sensitive conditions, such as acute myocardial infarction (AMI). However, there is little empirical evidence to show whether diversion is associated with worse patient outcomes. OBJECTIVE To analyze whether temporary ED closure on the day a patient experiences AMI, as measured by ambulance diversion hours of the nearest ED, is associated with increased mortality rates among patients with AMI. DESIGN, STUDY, AND PARTICIPANTS: A case-crossover design of 13,860 Medicare patients with AMI from 508 zip codes within 4 California counties (Los Angeles, San Francisco, San Mateo, and Santa Clara) whose admission date was between 2000 and 2005. Data included 100% Medicare claims data that covered admissions between 2000 and 2005, linked with date of death until 2006, and daily ambulance diversion logs from the same 4 counties. Among the hospital universe, 149 EDs were identified as the nearest ED to these patients. MAIN OUTCOME MEASURES The percentage of patients with AMI who died within 7 days, 30 days, 90 days, 9 months, and 1 year from admission (when their nearest ED was not on diversion and when that same ED was exposed to <6, 6 to <12, and ≥12 hours of diversion out of 24 hours on the day of admission). RESULTS Between 2000 and 2006, the mean (SD) daily diversion duration was 7.9 (6.1) hours. Based on analysis of 11,625 patients admitted to the ED between 2000 and 2005, and whose nearest ED had at least 3 diversion exposure levels (3541, 3357, 2667, and 2060 patients for no exposure, exposure to <6, 6 to <12, and ≥12 hours of diversion, respectively), there were no statistically significant differences in mortality rates between no diversion and exposure to less than 12 hours of diversion. Exposure to 12 or more hours of diversion was associated with higher 30-day mortality vs no diversion status (unadjusted mortality rate, 392 patients [19%] vs 545 patients [15%]; regression adjusted difference, 3.24 percentage points; 95% confidence interval [CI], 0.60-5.88); higher 90-day mortality (537 patients [26%] vs 762 patients [22%]; 2.89 percentage points; 95% CI, 0.13-5.64); higher 9-month mortality (680 patients [33%] vs 980 patients [28%]; 2.93 percentage points; 95% CI, 0.15-5.71); and higher 1-year mortality (731 patients [35%] vs 1034 patients [29%]; 3.04 percentage points; 95% CI, 0.33-5.75). CONCLUSION Among Medicare patients with AMI in 4 populous California counties, exposure to at least 12 hours of diversion by the nearest ED was associated with increased 30-day, 90-day, 9-month, and 1-year mortality.

The effect of hospital ownership choice on patient outcomes after treatment for acute myocardial infarction

I examine the effect of ownership choice on patient outcomes after the treatment for acute myocardial infarction. I find that for-profit and government hospitals have higher incidence of adverse outcomes than not-for-profit hospitals by 3-4%. In addition, the incidence of adverse outcomes increases by 7-9% after a not-for-profit hospital converts to for-profit ownership, but there is little change in patient outcomes in other forms of ownership conversion. The findings are robust, whether I use the entire sample or subsamples of hospitals that share similar hospital and market characteristics.

Understanding the risk factors of trauma center closures: do financial pressure and community characteristics matter?

Objectives:We analyze whether hazard rates of shutting down trauma centers are higher due to financial pressures or in areas with vulnerable populations (such as minorities or the poor). Materials and Methods:This is a retrospective study of all hospitals with trauma center services in urban areas in the continental US between 1990 and 2005, identified from the American Hospital Association Annual Surveys. These data were linked with Medicare cost reports, and supplemented with other sources, including the Area Resource File. We analyze the hazard rates of trauma center closures among several dimensions of risk factors using discrete-time proportional hazard models. Results:The number of trauma center closures increased from 1990 to 2005, with a total of 339 during this period. The hazard rate of closing trauma centers in hospitals with a negative profit margin is 1.38 times higher than those hospitals without the negative profit margin (P < 0.01). Hospitals receiving more generous Medicare reimbursements face a lower hazard of shutting down trauma centers (ratio: 0.58, P < 0.01) than those receiving below average reimbursement. Hospitals in areas with higher health maintenance organizations penetration face a higher hazard of trauma center closure (ratio: 2.06, P < 0.01). Finally, hospitals in areas with higher shares of minorities face a higher risk of trauma center closure (ratio: 1.69, P < 0.01). Medicaid load and uninsured populations, however, are not risk factors for higher rates of closure after we control for other financial and community characteristics. Conclusions:Our findings give an indication on how the current proposals to cut public spending could exacerbate the trauma closure particularly among areas with high shares of minorities. In addition, given the negative effect of health maintenance organizations on trauma center survival, the growth of Medicaid managed care population should be monitored. Finally, high shares of Medicaid or uninsurance by themselves are not independent risk factors for higher closure as long as financial pressures are mitigated. Targeted policy interventions and further research on the causes, are needed to address these systems-level disparities.

Effects of Iraq/Afghanistan Deployments on Major Depression and Substance Use Disorder: Analysis of Active Duty Personnel in the US Military

OBJECTIVES Our objective was to analyze the association between deployment characteristics and diagnostic rates for major depression and substance use disorder among active duty personnel. METHODS Using active duty personnel serving between 2001 and 2006 (n = 678,382) and deployment information from the Contingent Tracking System, we identified individuals diagnosed with substance use disorders and major depression from TRICARE health records. We performed logistic regression analysis to assess the effect of deployment location and length on these diagnostic rates. RESULTS Increased odds of diagnosis with both conditions were associated with deployment to Iraq or Afghanistan compared with nondeployed personnel and with Army and Marine Corps personnel compared with Navy and Air Force personnel. Increases in the likelihood of either diagnosis with deployment length were only observed among Army personnel. CONCLUSIONS There were increased substance use disorders and major depression across services associated with combat conditions. It would be important to assess whether the public health system has adequate resources to handle the increasing need of mental health services in this population.

Hospital ownership and financial performance: what explains the different findings in the empirical literature?

This study applies meta-analytic methods to conduct a quantitative review of the empirical literature on hospital ownership since 1990. We examine four financial outcomes across 40 studies: cost, revenue, profit margin, and efficiency. We find that variation in the magnitudes of ownership effects can be explained by a studys research focus and methodology. Studies using empirical methods that control for few confounding factors tend to find larger differences between for-profit and not-for-profit hospitals than studies that control for a wider range of confounding factors. Functional form and sample size also matter. Failure to apply log transformation to highly skewed expenditure data yields misleadingly large estimated differences between for-profits and not-for-profits. Studies with fewer than 200 observations also produce larger point estimates and wide confidence intervals.

Out-of-pocket health spending between low-and higher-income populations: who is at risk of having high expenses and high burdens?

Objective:We studied the effects of health insurance, health care needs, and demographic and area characteristics on out-of-pocket health care spending for low and higher income insured populations. Materials and Methods:We used the 2002 National Survey of Americas Families to analyze out-of-pocket health spending. People were classified into 3 levels of expenses based on their out-of-pocket health care spending and 3 levels of financial burden based on spending as a share of family income. We used a multinomial logit model to estimate the effect of insurance status and other factors on expense and burden levels. Results:Public insurance appears to offer the best financial protection from high out-of-pocket expenses and financial burden for those who are eligible. Families with private nongroup coverage have the highest odds of being in the high-expense and high-burden categories for all incomes. For higher-income families, having a family member in fair or poor health is a significant risk factor for high out-of-pocket expenses and financial burden. Having higher penetration of health maintenance organizations in an area appears to lower the odds of being in the high-burden category for all families. Conclusions:Health insurance may not prevent people from having high health care spending. Low-income people with serious health needs appear to be financially constrained and spend less on health care relative to higher-income people, and the presence of health maintenance organizations may help reduce out-of-pocket health care spending.

Rising Closures Of Hospital Trauma Centers Disproportionately Burden Vulnerable Populations

Closures of hospital trauma centers have accelerated since 2001. These closures may disproportionately affect disadvantaged communities. We evaluate how driving time between ZIP code areas and the nearest trauma centers-a proxy for access, given the time-sensitive nature of trauma care-changed nationwide during 2001-07. By 2007, sixty-nine million Americans (24 percent of the population) had to travel farther to the nearest trauma center than they did in 2001, and almost sixteen million people had to travel an additional thirty minutes or more. Communities with disproportionately high numbers of African American residents, uninsured people, and people living in poverty, as well as people living in rural areas, were more likely than others to be thus affected. Because mortality from traumatic injuries has also worsened for these vulnerable populations, policy makers should learn more about the possible connections-and consider such measures as paying trauma centers serving these communities higher amounts for treatment of injuries.

Changes in Hospital Performance after Ownership Conversions

This paper examines the effects of ownership conversions on hospital performance between 1987 and 1998 in areas of financial performance, staffing, capacity, and unprofitable care. Conversions to government and for-profit ownership both increased the profit margin: the former due to rising revenue, and the latter due to reduced operating costs and rising revenue. Hospitals that converted to for-profit ownership had the greatest reduction in staffing relative to other converted hospitals. There was little change in bed capacity after conversion to for-profit status, but some reductions in bed capacity after conversion to government or nonprofit status. No conversion of any kind led to a reduced amount of unprofitable care, but conversion to private ownership (nonprofit and for-profit) increased the probability of trauma center closures.