The Relationship between Hospital Volume and Mortality in Mechanical Ventilation: An Instrumental Variable Analysis

Objective. To examine the relationship between hospital volume and mortality for nonsurgical patients receiving mechanical ventilation.
Data Sources. Pennsylvania state discharge records from July 1, 2004, to June 30, 2006, linked to the Pennsylvania Department of Health death records and the 2000 United States Census.
Study Design. We categorized all general acute care hospitals in Pennsylvania ( n =169) by the annual number of nonsurgical, mechanically ventilated discharges according to previous criteria. To estimate the relationship between annual volume and 30-day mortality, we fit linear probability models using administrative risk adjustment, clinical risk adjustment, and an instrumental variable approach.
Principle Findings. Using a clinical measure of risk adjustment, we observed a significant reduction in the probability of 30-day mortality at higher volume hospitals (≥300 admissions per year) compared with lower volume hospitals (<300 patients per year; absolute risk reduction: 3.4%, p =.04). No significant volume–outcome relationship was observed using only administrative risk adjustment. Using the distance from the patient's home to the nearest higher volume hospital as an instrument, the volume–outcome relationship was greater than observed using clinical risk adjustment (absolute risk reduction: 7.0%, p =.01).
Conclusions. Care in higher volume hospitals is independently associated with a reduction in mortality for patients receiving mechanical ventilation. Adequate risk adjustment is essential in order to obtained unbiased estimates of the volume–outcome relationship.     

The Influence of Health Policy and Market Factors on the Hospital Safety Net

Objective. To examine how the financial pressures resulting from the Balanced Budget Act (BBA) of 1997 interacted with private sector pressures to affect indigent care provision.
Data Sources/Study Setting. American Hospital Association Annual Survey, Area Resource File, InterStudy Health Maintenance Organization files, Current Population Survey, and Bureau of Primary Health Care data.
Study Design. We distinguished core and voluntary safety net hospitals in our analysis. Core safety net hospitals provide a large share of uncompensated care in their markets and have large indigent care patient mix.
Voluntary safety net hospitals provide substantial indigent care but less so than core hospitals. We examined the effect of financial pressure in the initial year of the 1997 BBA on uncompensated care for three hospital groups. Data for 1996–2000 were analyzed using approaches that control for hospital and market heterogeneity.
Data Collection/Extraction Methods. All urban U.S. general acute care hospitals with complete data for at least 2 years between 1996 and 2000, which totaled 1,693 institutions.
Principal Findings. Core safety net hospitals reduced their uncompensated care in response to Medicaid financial pressure. Voluntary safety net hospitals also responded in this way but only when faced with the combined forces of Medicaid and private sector payment pressures. Nonsafety net hospitals did not exhibit similar responses.
Conclusions. Our results are consistent with theories of hospital behavior when institutions face reductions in payment. They raise concern given continuing state budget crises plus the focus of recent federal deficit reduction legislation intended to cut Medicaid expenditures.     

Factors associated with the provision of uncompensated care in Pennsylvania hospitals

Data from 190 Pennsylvania hospitals in 1995 were used in regression analysis of the determinants of uncompensated care and profitability. Uncompensated care as a percentage of operating expenses was negatively related with hospital size and positively associated with obstetrical services emphasis, emergency visit mix, area unemployment rate, and sole community hospital status. Hospital profitability was not associated with uncompensated care; it was negatively associated with HMO penetration, Medicare and Medicaid share of admissions and religious ownership; and it was positively associated with medium size. Pennsylvania hospitals may have been shielded from the financial burdens of uncompensated care by the availability of funds from other sources that may not be available in the future. Consequently, unless new sources of funding are developed or insurance coverage expanded, financial pressures from providing uncompensated care may cause hospitals to face the dilemma of abandoning uninsured patients or risking financial insolvency.     

Does uninsurance affect the health outcomes of the insured? Evidence from heart attack patients in California

In this paper, I examine the impact of uninsured patients on the in-hospital mortality rate of insured heart attack patients. I employ panel data models using patient discharge and hospital financial data from California (1999-2006). My results indicate that uninsured patients have an economically significant effect that increases the mortality rate of insured heart attack patients. I show that these results are not driven by alternative explanations, including reverse causality, patient composition effects, sample selection or unobserved trends and that they are robust to a host of specification checks. The primary channel for the observed spillover effects is increased hospital uncompensated care costs. Although data limitations constrain my capacity to check how hospitals change their provision of care to insured heart attack patients in response to reduced revenues, the evidence I have suggests a modest increase in the quantity of cardiac services without a corresponding increase in hospital staff.     

BBA impacts on hospital residents, finances, and Medicare subsidies

Concern over rapidly rising Medicare expenditures prompted Congress to pass the 1997 Balanced Budget Act (BBA) that included provisions reducing graduate medical education (GME) payments and capped the growth in residents for payment purposes. Using Medicare cost reports through 2001, we find that both actual and capped residents continued to grow post-BBA. While teaching hospital total margins declined, GME payment reductions of approximately 17 percent had minimal impact on revenue growth (-0.5 percent annually). Four years after BBA, residents remained a substantial line of business for nearly one-half of teaching hospitals with Medicare effective marginal subsidies exceeding resident stipends by nearly $50,000 on average. Coupled with an estimated replacement cost of over $100,000 per resident, it is not surprising that hospitals accepted nearly 4,000 residents beyond their allowable payment caps in just 4 years post-BBA.     

The relationship between the Balanced Budget Act (BBA) and hospital profitability

The Balanced Budget Act of 1997 (BBA) reduced the payment for fees for service providers and reduced the subsidy paid by the government for teaching hospitals. Since the passage of such cost containment measures, debates regarding their impact on hospitals, graduate medical education, and access to health care were raised. The need to examine the effect of such payment reduction on hospital profitability was widely ignored. We examined the relationship between the BBA and hospital profitability by using return on assets to measure profitability, by running an ordinary least squares regression for 1996 as pre-BBA and 1999 as post-BBA. We controlled for variables that were not included in previous literature, such as disproportionate share hospital status, critical access hospital status, and graduate medical education, measured by teaching hospitals to measure the effect of BBA cuts on teaching hospitals. Furthermore we incorporated several economic, financial, and utilization variables in the model. We used 1996 and 1999 data in our analysis to bridge potential effects of the BBA. To locate hospitals that changed ownership status we cross-matched the Medicare Cost Report data with the American Hospital Association Annual Survey. We found that overall hospital profitability declined as a result of the introduction of the BBA; however, small rural hospitals that converted to critical access status enjoyed improvement in financial status over the period of our study. Hospitals that converted to for-profit status did not improve in financial status, and showed a lower earning after the conversation. Our results show that the BBA had a negative effect on hospitals because of cuts in its reimbursement policy, except for critical access hospitals, which show improvement because of their exemption from the prospective payment system. Our study differs from others by using national comprehensive data for years that focus exclusively on the Balanced Budget Act period. We deliberately excluded any period that might be affected by the Balanced Budget Refinement Act (BBRA) of 1999, to clarify the severity of the BBA cut on hospital financial performance. Furthermore, because of the few studies that focused on the effect of the BBA on hospital profitability, this study is an important addition to the literature.     

Inpatient Hospital Utilization among the Uninsured Near Elderly: Data and Policy Implications for West Virginia

Objective. To inform state policy discussions about the insurance coverage of the near elderly in West Virginia (WV) and the impact of the uninsured near elderly on hospitals in the state.
Data Sources. 2003 West Virginia Uniform Bill (UB) hospital discharge data. The data represent all adult inpatient discharges in the state during the year.
Study Design. We compare the near elderly with other adults and examine differences by insurance status. Key variables include volume of discharges, health insurance coverage, patient characteristics, and charges incurred.
Findings. The near elderly constitute the largest group of nonelderly adult inpatient hospital discharges. They are more likely than younger adults to be admitted for emergency conditions; have comorbidities and complications; have longer hospital stays; and incur higher charges on average. Although the near elderly are least likely to be uninsured, they represent the second largest group of uninsured discharges and incur the most in uninsured charges.
Conclusions. The specific needs of the near elderly warrant consideration in WV's (and other states') ongoing development and evaluation of policies aimed at reducing uncompensated care costs, including programs to expand access to health insurance and primary and mental health care among the uninsured.     

Hospital nurse practice environments and outcomes for surgical oncology patients

Objective. To examine the effect of nursing practice environments on outcomes of hospitalized cancer patients undergoing surgery.
Data Sources. Secondary analysis of cancer registry, inpatient claims, administrative and nurse survey data collected in Pennsylvania for 1998–1999.
Study Design. Nurse staffing (patient to nurse ratio), educational preparation (proportion of nurses holding at least a bachelor's degree), and the practice environment (Practice Environment Scale of the Nursing Work Index) were calculated from a survey of nurses and aggregated to the hospital level. Logistic regression models predicted the odds of 30-day mortality, complications, and failure to rescue (death following a complication).
Principal Findings. Unadjusted death, complication, and failure to rescue rates were 3.4, 35.7, and 9.3 percent, respectively. Nurse staffing and educational preparation of registered nurses were significantly associated with patient outcomes. After adjusting for patient and hospital characteristics, patients in hospitals with poor nurse practice environments had significantly increased odds of death (odds ratio, 1.37; 95 percent confidence interval, 1.07–1.76) and of failure to rescue (odds ratio, 1.48; 95 percent confidence interval, 1.07–2.03). Receipt of care in National Cancer Institute-designated cancer centers significantly decreased the odds of death, which can be explained partly by better nurse practice environments.
Conclusions. This study is one of the first to examine the predictive validity of the National Quality Forum's endorsed measure of the nurse practice environment. Improvements in the quality of nurse practice environments could reduce adverse outcomes for hospitalized surgical oncology patients.     

Long‐Term Impact of Medicare Payment Reductions on Patient Outcomes

Objective

To examine the long-term impact of Medicare payment reductions on patient outcomes for Medicare acute myocardial infarction (AMI) patients.

Data Sources

Analysis of secondary data compiled from 100 percent Medicare Provider Analysis and Review between 1995 and 2005, Medicare hospital cost reports, Inpatient Prospective Payment System Payment Impact Files, American Hospital Association annual surveys, InterStudy, Area Resource Files, and County Business Patterns.

Study Design

We used a natural experiment—the Balanced Budget Act (BBA) of 1997—as an instrument to predict cumulative Medicare revenue loss due solely to the BBA, and basing on the predicted loss categorized hospitals into small, moderate, or large payment-cut groups and followed Medicare AMI patient outcomes in these hospitals over an 11-year panel between 1995 and 2005.

Principal Findings

We found that while Medicare AMI mortality trends remained similar across hospitals between pre-BBA and initial-BBA periods, hospitals facing large payment cuts saw smaller improvement in mortality rates relative to that of hospitals facing small cuts in the post-BBA period. Part of the relatively higher AMI mortalities among large-cut hospitals might be related to reductions in staffing levels and operating costs, and a small part might be due to patient selection.

Conclusions

We found evidence that hospitals facing large Medicare payment cuts as a result of BBA of 1997 were associated with deteriorating patient outcomes in the long run. Medicare payment reductions may have an unintended consequence of widening the gap in quality across hospitals.     

The relationship between the Balanced Budget Act and length of stay for Medicare patients in US hospitals

Background  The Balanced Budget Act (BBA) of 1997 and Balanced Budget Refinement Act (BBRA) of 1999 led to deep financial cuts for hospitals and nursing homes. Objectives  We examine the effects of these acts on hospital length of stay (LOS) for Medicare recipients. Methods  Using data for all short-stay community hospitals in the country, we compared LOS for Medicare patients before and after the BBA/BBRA relative to known determinants of LOS, e.g., hospital ownership, region, beds, financial performance, and conversion/change in ownership type. Results  Hospital LOS was reduced as a result of the acts. Reductions were more apparent for larger urban hospitals that provided safety-net services. LOS varied slightly by hospital ownership. Conclusion  This study is among the first to evaluate the impact of BBA and BBRA on hospital services. These acts had a negative effect on the ability of hospitals to continue offering safety-net services and negatively affected LOS.      

Acute Myocardial Infarction and Coronary Artery Bypass Grafting Outcomes in Specialty and General Hospitals: Analysis of State Inpatient Data

Objective. Compare characteristics and outcomes of patients hospitalized in specialty cardiac and general hospitals for acute myocardial infarction (AMI) and coronary artery bypass grafting (CABG).
Data. 2000–2005 all-payor administrative data from Arizona, California, Texas, and Wisconsin.
Study Design. We identified patients admitted to specialty and competing general hospitals with AMI or CABG and compared patient demographics, comorbidity, and risk-standardized mortality in specialty and general hospitals.
Principal Findings. Specialty hospitals admitted a lower proportion of women and blacks and treated patients with less comorbid illness than general hospitals. Unadjusted in-hospital AMI mortality for Medicare enrollees in specialty and general hospitals was 6.1 and 10.1 percent ( p <.0001) and for non-Medicare enrollees was 2.8 and 4.0 percent ( p <.04). Unadjusted in-hospital CABG mortality for Medicare enrollees in specialty and general hospitals was 3.2 and 4.7 percent ( p <.01) and for non-Medicare enrollees was 1.1 and 1.8 percent ( p =.02). After adjusting for patient characteristics and hospital volume, risk-standardized in-hospital mortality for all AMI patients was 2.7 percent for specialty hospitals and 4.1 percent for general hospitals ( p <.001) and for CABG was 1.5 percent for specialty hospitals and 2.0 percent for general hospitals ( p =.07).
Conclusions. In-hospital mortality in specialty hospitals was lower than in general hospitals for AMI but similar for CABG. Our results suggest that specialty hospitals may offer significantly better outcomes for AMI but not CABG.     

Market reform in New Jersey and the effect on mortality from acute myocardial infarction

OBJECTIVE: To determine whether mortality rates for patients with acute myocardial infarction (AMI) changed in New Jersey after implementation of the Health Care Reform Act, which reduced subsidies for hospital care for the uninsured and changed hospital payment to price competition from a rate-setting system based on hospital cost. DATA SOURCES/STUDY SETTING: Patient discharge data from hospitals in New Jersey and New York from 1990 through 1996 and the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS). STUDY DESIGN: A comparison between states over time of unadjusted and risk-adjusted mortality and cardiac procedure rates. DATA COLLECTION: Discharge data were obtained for 286,640 patients with the primary diagnosis of AMI admitted to hospitals in New Jersey or New York from 1990 through 1996. Records of 364,273 NIS patients were used to corroborate time trends. PRINCIPAL FINDINGS: There were no significant differences in AMI mortality among insured patients in New Jersey relative to New York or the NIS. However, there was a relative increase in mortality of 41 to 57 percent among uninsured New Jersey patients post-reform, and their rates of expensive cardiac procedures decreased concomitantly. CONCLUSIONS: The introduction of hospital price competition and reductions in subsidies for hospital care of the uninsured were associated with an increased mortality rate among uninsured New Jersey AMI patients. A relative decrease in the use of cardiac procedures in New Jersey may partly explain this finding. Additional studies should be done to identify whether other market reforms have been associated with changes in the quality of care.     

Use of Prolonged Travel to Improve Pediatric Risk-Adjustment Models

Objective. To determine whether travel variables could explain previously reported differences in lengths of stay (LOS), readmission, or death at children's hospitals versus other hospital types.
Data Source. Hospital discharge data from Pennsylvania between 1996 and 1998.
Study Design. A population cohort of children aged 1–17 years with one of 19 common pediatric conditions was created ( N =51,855). Regression models were constructed to determine difference for LOS, readmission, or death between children's hospitals and other types of hospitals after including five types of additional illness severity variables to a traditional risk-adjustment model.
Principal Findings. With the traditional risk-adjustment model, children traveling longer to children's or rural hospitals had longer adjusted LOS and higher readmission rates. Inclusion of either a geocoded travel time variable or a nongeocoded travel distance variable provided the largest reduction in adjusted LOS, adjusted readmission rates, and adjusted mortality rates for children's hospitals and rural hospitals compared with other types of hospitals.
Conclusions. Adding a travel variable to traditional severity adjustment models may improve the assessment of an individual hospital's pediatric care by reducing systematic differences between different types of hospitals.     

Future financial viability of rural hospitals

Policymakers are concerned that some rural hospitals have suffered significant losses under the Balanced Budget Act (BBA) of 1997 and that access to inpatient and emergency care may be at risk. This article projects that the median total profit margin for rural hospitals will fall from 4 percent in 1997 to between 2.5 and 3.7 percent after the BBA, Balanced Budget Refinement Act (BBRA) of 1999, and Benefits Improvement and Protection Act (BIPA) of 2000 are fully implemented in 2004. The Critical Access Hospital (CAH) Program is expected to prevent reductions in inpatient and outpatient prospective payments from causing an increase in rural hospital closures.     

Hospital and Geographic Variability in Thirty‐Day All‐Cause Mortality Following Colorectal Cancer Surgery

Objective

To assess hospital and geographic variability in 30-day mortality after surgery for CRC and examine the extent to which sociodemographic, area-level, clinical, tumor, treatment, and hospital characteristics were associated with increased likelihood of 30-day mortality in a population-based sample of older CRC patients.

Data Sources/Study Setting

Linked Surveillance Epidemiology End Results (SEER) and Medicare data from 47,459 CRC patients aged 66 years or older who underwent surgical resection between 2000 and 2005, resided in 13,182 census tracts, and were treated in 1,447 hospitals.

Study Design

An observational study using multilevel logistic regression to identify hospital- and patient-level predictors of and variability in 30-day mortality.

Data Collection/Extraction Methods

We extracted sociodemographic, clinical, tumor, treatment, hospital, and geographic characteristics from Medicare claims, SEER, and census data.

Principal Findings

Of 47,459 CRC patients, 6.6 percent died within 30 days following surgery. Adjusted variability in 30-day mortality existed across residential census tracts (predicted mortality range: 2.7–12.3 percent) and hospitals (predicted mortality range: 2.5–10.5 percent). Higher risk of death within 30 days was observed for CRC patients age 85+ (12.7 percent), census-tract poverty rate >20 percent (8.0 percent), two or more comorbid conditions (8.8 percent), stage IV at diagnosis (15.1 percent), undifferentiated tumors (11.6 percent), and emergency surgery (12.8 percent).

Conclusions

Substantial, but similar variability was observed across census tracts and hospitals in 30-day mortality following surgery for CRC in patients 66 years and older. Risk of 30-day mortality is driven not only by patient and hospital characteristics but also by larger social and economic factors that characterize geographic areas.     

Relationships between in-hospital and 30-day standardized hospital mortality: implications for profiling hospitals

OBJECTIVE: To examine the relationship of in-hospital and 30-day mortality rates and the association between in-hospital mortality and hospital discharge practices. DATA SOURCES/STUDY SETTING: A secondary analysis of data for 13,834 patients with congestive heart failure who were admitted to 30 hospitals in northeast Ohio in 1992-1994. DESIGN: A retrospective cohort study was conducted. DATA COLLECTION: Demographic and clinical data were collected from patients' medical records and were used to develop multivariable models that estimated the risk of in-hospital and 30-day (post-admission) mortality. Standardized mortality ratios (SMRs) for in-hospital and 30-day mortality were determined by dividing observed death rates by predicted death rates. PRINCIPAL FINDINGS: In-hospital SMRs ranged from 0.54 to 1.42, and six hospitals were classified as statistical outliers (p <.05); 30-day SMRs ranged from 0.63 to 1.73, and seven hospitals were outliers. Although the correlation between in-hospital SMRs and 30-day SMRs was substantial (R = 0.78, p < .001), outlier status changed for seven of the 30 hospitals. Nonetheless, changes in outlier status reflected relatively small differences between in-hospital and 30-day SMRs. Rates of discharge to nursing homes or other inpatient facilities varied from 5.4 percent to 34.2 percent across hospitals. However, relationships between discharge rates to such facilities and in-hospital SMRs (R = 0.08; p = .65) and early post-discharge mortality rates (R = 0.23; p = .21) were not significant. CONCLUSIONS: SMRs based on in-hospital and 30-day mortality were relatively similar, although classification of hospitals as statistical outliers often differed. However, there was no evidence that in-hospital SMRs were biased by differences in post-discharge mortality or discharge practices.     

What Happens When Hospital-Based Skilled Nursing Facilities Close? A Propensity Score Analysis

Objective. To assess the effects of hospital-based skilled nursing facility (HBSNF) closures on health care utilization, spending, and outcomes among Medicare fee-for-service beneficiaries.
Data Sources. One hundred percent Medicare fee-for-service claims files for 1997–2002 were merged with Medicare Provider of Services files and beneficiary-level enrollment records.
Study Design. Medicare spending, the use of postacute care, and health outcomes, were compared among hospitals that did and did not close their HBSNFs between 1997 and 2001. Hospitals were stratified according to propensity scores (i.e., predicted probability of closure from a logistic regression) and analyses were conducted within these strata.
Principal Findings. HBSNF closures were associated with increased utilization of alternative postacute care settings, and longer acute care hospital stays. Because of increased use of alternative settings, HBSNF closures were associated with a slight increase in total Medicare spending. There are no statistically robust associations between HBSNF closures and changes in either mortality or rehospitalization.
Conclusions. HBSNF closures altered utilization patterns, but there is no indication that closures adversely affect beneficiaries' health outcomes.     

Anesthesia Provider Model, Hospital Resources, and Maternal Outcomes

Objective. Determine the ability of anesthesia provider model and hospital resources to explain maternal outcome variation.
Data Source/Study Setting. 1,141,641 obstetrical patients from 369 hospitals that reported at least one live birth in 2002 in six representative states.
Study Design. Logistic regression of death, anesthesia complication, nonanesthesia maternal complication, and obstetrical trauma for all patients and those having cesarean deliveries on anesthesia provider model, obstetrical and anesthesia, and patient variables.
Data Collection/Extraction Methods. Data was assembled from information given by hospitals to state agencies and from a 2004 survey of obstetrical organization resources.
Principal Findings. Anesthesia complication rates in anesthesiologist-only hospitals were 0.27 percent compared with 0.23 percent in certified registered nurse anesthetist (CRNA) only hospitals. Rates among other provider models varied from 0.24 to 0.37 percent with none statistically different from the anesthesiologist-only hospitals. A similar pattern was observed for rates of other outcomes. Multivariate analysis found no systematic differences between hospitals with anesthesiologist-only models and models using CRNAs. There was no consistent pattern of association of other hospital or patient characteristics with outcomes.
Conclusion. Hospitals that use only CRNAs, or a combination of CRNAs and anesthesiologists, do not have systematically poorer maternal outcomes compared with hospitals using anesthesiologist-only models.     

Multihospital System Membership and Patient Treatments, Expenditures, and Outcomes

Objective. To determine the relationship between hospital membership in systems and the treatments, expenditures, and outcomes of patients.
Data Sources. The Medicare Provider Analysis and Review dataset, for data on Medicare patients admitted to general medical-surgical hospitals between 1985 and 1998 with a diagnosis of acute myocardial infarction (AMI); the American Hospital Association Annual Survey, for data on hospitals.
Study Design. A multivariate regression analysis. An observation is a fee-for-service Medicare AMI patient admitted to a study hospital. Dependent variables include patient transfers, catheterizations, angioplasties or bypass surgeries, 90-day mortality, and Medicare expenditures. Independent variables include system participation, other admission hospital and patient traits, and hospital and year fixed effects. The five-part system definition incorporates the size and location of the index admission hospital and the size and distance of its partners.
Principal Findings. While the effects of multihospital system membership on patients are in general limited, patients initially admitted to small rural system hospitals that have big partners within 100 miles experience lower mortality rates than patients initially admitted to independent hospitals. Regression results show that to the extent system hospital patients experience differences in treatments and outcomes relative to patients of independent hospitals, these differences remain even after controlling for the admission hospital's capacity to provide cardiac services.
Conclusions. Multihospital system participation may affect AMI patient treatment and outcomes through factors other than cardiac service offerings. Additional investigation into the nature of these factors is warranted.