Certificate of need and the quality of cardiac surgery

Certificate of Need Laws in Health Care: Past, Present, and Future

Certificate of need (CON) laws limit the supply of health care services in about two-thirds of U.S. states. The regulations require those who wish to offer new services or expand existing services to first prove to a regulator that the care is needed. While advocates for the regulation have offered several rationales for its continuance, the balance of evidence suggests that the rules protect incumbent providers from competition at the expense of patients, payors, and would-be competitors. In this article, I review the history of CON laws in health care, summarize the large literature evaluating them, and briefly sketch options for reform.JEL Classification: I11, I18, H75.

Government Regulation and Percutaneous Coronary Intervention Volume, Access and Outcomes: Insights From the Washington State Cardiac Care Outcomes Assessment Program

Background

It is unclear how to geographically distribute percutaneous coronary intervention (PCI) programs to optimize patient outcomes. The Washington State Certificate of Need program seeks to balance hospital volume and patient access through regulation of elective PCI.

Methods and Results

We performed a retrospective cohort study of all non‐Veterans Affairs hospitals with PCI programs in Washington State from 2009 to 2018. Hospitals were classified as having (1) full PCI services and surgical backup (legacy hospitals, n=17); (2) full services without surgical backup (new certificate of need [CON] hospitals, n=9); or (3) only nonelective PCI without surgical backup (myocardial infarction [MI] access hospitals, n=9). Annual median hospital‐level volumes were highest at legacy hospitals (605, interquartile range, 466–780), followed by new CON, (243, interquartile range, 146–287) and MI access, (61, interquartile range, 23–145). Compared with MI access hospitals, risk‐adjusted mortality for nonelective patients was lower for legacy (odds ratio [OR], 0.59 [95% CI, 0.48–0.72]) and new‐CON hospitals (OR, 0.55 [95% CI, 0.45–0.65]). Legacy hospitals provided access within 60 minutes for 90% of the population; addition of new CON and MI access hospitals resulted in only an additional 1.5% of the population having access within 60 minutes.

Conclusions

Many PCI programs in Washington State do not meet minimum volume standards despite regulation designed to consolidate elective PCI procedures. This CON strategy has resulted in a tiered system that includes low‐volume centers treating high‐risk patients with poor outcomes, without significant increase in geographic access. CON policies should re‐evaluate the number and distribution of PCI programs.

Certificate of Need Laws and Health Care Use during the COVID-19 Pandemic

This paper investigates the impact of state-level Certificate-of-Need (CON) laws on COVID and non-COVID deaths in the United States during the SARS-CoV-2 pandemic. CON laws limit the expansion and acquisition of new medical services, such as new hospital beds. The coronavirus pandemic created a surge in demand for medical services, which might be exacerbated in some states that have CON laws. Our investigation focuses on mortality due to COVID and non-COVID reasons and understanding how these laws affect access to healthcare for illnesses that might require similar medical equipment to COVID patients. We find that states with high healthcare use due to COVID that reformed their CON laws during the pandemic had a reduction in mortality resulting from COVID-19, septicemia, diabetes, chronic lower respiratory disease, influenza or pneumonia, and Alzheimer’s Disease, relative to non-reforming CON states.

The Economics of a Bed Shortage: Certificate-of-Need Regulation and Hospital Bed Utilization during the COVID-19 Pandemic

Certificate-of-need (CON) laws are intended to restrain health care spending by limiting the acquisition of duplicative capital and the initiation of unnecessary services. Critics contend that need is difficult to objectively assess, especially considering the risks and uncertainty inherent in health care. We compare statewide bed utilization rates and hospital-level bed utilization rates in bed CON and non-bed CON states during the COVID-19 pandemic. Controlling for other possibly confounding factors, we find that states with bed CONs had 12 percent higher bed utilization rates and 58 percent more days in which more than 70 percent of their beds were used. Individual hospitals in bed CON states were 27 percent more likely to utilize all of their beds. States that relaxed CON requirements to make it easier for hospitals to meet the surge in demand did not experience any statistically significant decreases in bed utilization or number of days above 70 percent of capacity. Nor were hospitals in states that relaxed their CON requirements any less likely to use all their beds. Certificate-of-need laws seem to have exacerbated the risk of running out of beds during the COVID-19 pandemic. State efforts to relax these rules had little immediate effect on reducing this risk.

The impact of certificate of need laws on heart attack mortality: Evidence from county borders

Certificate of need (CON) regulations requires that health care providers obtain state approval before offering a new service or expanding existing facilities. The purported goal of CON regulations is to reduce health care costs by generating regional economies of scale and reducing redundant investments resulting from excessive competition. Critics of CON regulations note that the regulatory environment increases the costs of expansion and may incentivize health care providers to forgo capital investment, which can have a negative effect on health outcomes. To estimate the net effect of CON regulations, I use a border discontinuity design to measure within-regional heart attack mortality spanning 1968 to 1982. I estimate that CON regulations led to an increase in heart attack deaths, by 6%-10%, three years after the policy was enacted.

Certificate of need laws: a systematic review and cost-effectiveness analysis

BACKGROUND

Certificate of Need (CON) laws, currently in place in 35 US states, require certain health care providers to obtain a certification of their economic necessity from a state board before opening or undertaking a major expansion. We conduct the first systematic review and cost-effectiveness analysis of these laws.

METHODS

We review 90 articles to summarize the evidence on how certificate of need laws affect regulatory costs, health expenditures, health outcomes, and access to care. We use the findings from the systematic review to conduct a cost-effectiveness analysis of CON.

RESULTS

The literature provides mixed results, on average finding that CON increases health expenditures and overall elderly mortality while reducing heart surgery mortality. Our cost-effectiveness analysis estimates that the costs of CON laws somewhat exceed their benefits, although our estimates are quite uncertain.

CONCLUSIONS

The literature has not yet reached a definitive conclusion on how CON laws affect health expenditures, outcomes, or access to care. While more and higher quality research is needed to reach confident conclusions, our cost-effectiveness analysis based on the existing literature shows that the expected costs of CON exceed its benefits.

Association of Statewide Certificate of Need Regulations With Percutaneous Coronary Intervention Appropriateness and Outcomes

Background Certificate of need ( CON ) regulations are intended to coordinate new healthcare services, limit expansion of unnecessary new infrastructure, and limit healthcare costs. However, there is limited information about the association of CON regulations with the appropriateness and outcomes of percutaneous coronary interventions ( PCI ). The study sought to characterize the association between state CON regulations and PCI appropriateness. Methods and Results We used data from the American College of Cardiology's Cath PCI Registry to analyze 1 268 554 PCI s performed at 1297 hospitals between January 2010 and December 2011. We used the Appropriate Use Criteria to classify PCI procedures as appropriate, maybe appropriate, or rarely appropriate and used Chi-square analyses to assess whether the proportions of PCI s in each Appropriate Use Criteria category varied depending on whether the procedure had been performed in a state with or without CON regulations. Analyses were repeated stratified by whether or not the procedure had been performed in the setting of an acute coronary syndrome ( ACS ). Among 1 268 554 PCI procedures, 674 384 (53.2%) were performed within 26 CON states. The proportion of PCI s classified as rarely appropriate in CON states was slightly lower compared with non- CON states (3.7% versus 4.0%, P<0.01). Absolute differences were larger among non- ACS PCI (23.1% versus 25.0% [ P<0.01]) and were not statistically significantly different in ACS (0.62% versus 0.63% [ P>0.05]). Conclusions States with CON had lower proportions of rarely appropriate PCI s, but the absolute differences were small. These findings suggest that CON regulations alone may not limit rarely appropriate PCI among patients with and without ACS .

Does certificate of need law enhance competition in inpatient care market? An empirical analysis

This article investigates the impact of Certificate of Need (CON) laws on competition in the inpatient care market. One of the major criticisms of these laws is that it may hinder competition in the health care market, which can lead to higher prices. However, from a theoretical standpoint, CON laws could also promote competition by limiting excessive expansion from incumbents. Our main conclusion is that CON laws by and large enhanced competition in the inpatient market during the period of our study. This indicates that the effects of CON laws to hinder predatory behavior could dominate its effects of preventing new entrants into the inpatient care market. We do not find statistically significant evidence to reject the exogeneity assumption of either CON laws or their stringency in our study. We also find factors such as proportion of population aged 18-44, proportion of Asian American population, obesity rate, political environment, etc., in a state significantly impact competition. Our findings could shed some light to public policy makers when deciding the appropriate health programs or legislative framework to promote health care market competition and thereby facilitate quality health care.

The Effect of Certificate of Need Laws on All-Cause Mortality

OBJECTIVE

To test how Certificate of Need laws affect all-cause mortality in the United States.

DATA SOURCES

The data of 1992-2011 all-cause mortality are from the Center for Disease Control's Compressed Mortality File; control variables are from the Current Population Survey, Behavioral Risk Factor Surveillance System, and Area Health Resources File; and data on Certificate of Need laws are from Stratmann and Russ ().

STUDY DESIGN

Using fixed- and random-effects regressions, I test how the scope of state Certificate of Need laws affects all-cause mortality within US counties.

PRINCIPAL FINDINGS

Certificate of Need laws have no statistically significant effect on all-cause mortality. Point estimates indicate that if they have any effect, they are more likely to increase mortality than decrease it.

CONCLUSIONS

Proponents of Certificate of Need laws have claimed that they reduce mortality by concentrating more care into fewer, larger facilities that engage in learning-by-doing. However, I find no evidence that these laws reduce all-cause mortality.

How Do Hospitals Respond to Market Entry? Evidence from a Deregulated Market for Cardiac Revascularization

Regulatory entry barriers to hospital service markets, namely Certificate of Need (CON) regulations, are enforced in many US states. Policy makers in other states are considering reinstating CON policies in tandem with service expansions mandated under the Affordable Care Act. Although previous studies examined the volume effects of CON, demand responses to actual entry into local hospital markets are not well understood. In this paper, we empirically examine the demand-augmenting, demand-redistribution, and risk-allocation effects of hospital entry by studying the cardiac revascularization markets in Pennsylvania, a state in which dynamic market entry occurred after repeal of CON in 1996. Results from interrupted time-series analyses indicate demand-augmenting effects for coronary artery bypass graft (CABG) and business-stealing effects for percutaneous coronary intervention (PCI) procedures: high entrant market share mitigated the declining incidence of CABG, but it had no significant effect on the rising trend in PCI use, among patients with coronary artery disease. We further find evidence that entry by new cardiac surgery centers tended to sort high-severity patients into the more invasive CABG procedure and low-severity patients into the less invasive PCI procedures. These findings underscore the importance of considering market-level strategic responses by hospitals when regulatory barriers are rescinded.

Competition and the impact of online hospital report cards

Information on the quality of healthcare gives providers an incentive to improve care, and this incentive should be stronger in more competitive markets. We examine this hypothesis by studying Pennsylvanian hospitals during the years 1995-2004 to see whether those hospitals located in more competitive markets increased the quality of the care provided to Medicare patients after report cards rating the quality of their Coronary Artery Bypass Graft programs went online in 1998. We find that after the report cards went online, hospitals in more competitive markets used more resources per patient, and achieved lower mortality among more severely ill patients.

State deregulation and Medicare costs for acute cardiac care

Past literature suggests that Certificate of Need (CON) regulations for cardiac care were ineffective in improving quality, but less is known about the effect of CON on patient costs. We analyzed Medicare data for 1991-2002 to test whether states that dropped CON experienced changes in costs or reimbursements for coronary artery bypass graft (CABG) surgery or percutaneous coronary interventions. We found that states that dropped CON experienced lower costs per patient for CABG but not for percutaneous coronary intervention. Average Medicare reimbursement was lower for both procedures in states that dropped CON. The cost savings from removing CON regulations slightly exceed the total fixed costs of new CABG facilities that entered after deregulation. Assuming continued cost savings past 2002, the savings from deregulating CABG surgery outweigh the fixed costs of new entry. Thus, CON regulations for CABG may not be justified in terms of either improving quality or controlling cost growth.

The impact of certificate of need programs on neonatal intensive care units

OBJECTIVE

To determine the impact of state certificate of need programs (CON) on the number of hospitals with neonatal intensive care units (NICU) and the number of NICU beds.

STUDY DESIGN

The presence of a CON program was verified from each state's department of health. Multivariable regression models determined the association between the absence of a CON program and each outcome after controlling for socioeconomic and demographic differences between states.

RESULT

A total of 30 states had CON programs that oversaw NICUs in 2008. Absence of such programs was associated with more hospitals with a NICU (Rate Ratio (RR) 2.06, 95% CI 1.74 to 2.45) and NICU beds (RR 1.96, 95% CI 1.89 to 2.03) compared with states with CON legislation, and increased all-infant mortality rates in states with a large metropolitan area.

CONCLUSION

There has been an erosion of CON programs that oversee NICUs. CON programs are associated with more efficient delivery of neonatal care.

Do bad report cards have consequences? Impacts of publicly reported provider quality information on the CABG market in Pennsylvania

Since 1992, the Pennsylvania Health Care Cost Containment Council (PHC4) has published cardiac care report cards for coronary artery bypass graft (CABG) surgery providers. We examine the impact of CABG report cards on a provider's aggregate volume and volume by patient severity and then employ a mixed logit model to investigate the matching between patients and providers. We find a reduction in volume of poor performing and unrated surgeons' volume but no effect on more highly rated surgeons or hospitals of any rating. We also find that the probability that patients, regardless of severity of illness, receive CABG surgery from low-performing surgeons is significantly lower.

Effects of report cards on referral patterns to cardiac surgeons

Patients' choices of specialist physicians may be guided by referring physicians and report cards. I examine referral patterns to cardiac surgeons to assess whether publication of the May 2002 edition of Pennsylvania's Guide to Coronary Artery Bypass Graft Surgery added information to what referring physicians already knew. To do so, I developed a counterfactual scenario, including a simulated analogue report card, based on comparable data from Florida, a state without CABG report cards. My analysis failed to detect a significant change in referral patterns to either low-mortality or high-mortality cardiac surgeons. At the same time, referring physicians on average appear to have been knowledgeable about the relative performance of cardiac surgeons without report cards. Future report card efforts might benefit from incorporating the quality signals contained in referral patterns.

Certificate of Need (CON) for cardiac care: controversy over the contributions of CON

OBJECTIVES

To test whether state Certificate of Need (CON) regulations influence procedural mortality or the provision of coronary artery bypass graft surgery (CABG) and percutaneous coronary interventions (PCI).

DATA SOURCES

Medicare inpatient claims obtained for 1989-2002 for patients age 65+ who received CABG or PCI.

STUDY DESIGN

We used differences-in-differences regression analysis to compare states that dropped CON during the sample period with states that kept the regulations. We examined procedural mortality, the number of hospitals in the state performing CABG or PCI, mean hospital volume, and statewide procedure volume for CABG and PCI.

PRINCIPAL FINDINGS

States that dropped CON experienced lower CABG mortality rates relative to states that kept CON, although the differential is not permanent. No such mortality difference is found for PCI. Dropping CON is associated with more providers statewide and lower mean hospital volume for both CABG and PCI. However, statewide procedure counts remain the same.

CONCLUSIONS

We find no evidence that CON regulations are associated with higher quality CABG or PCI. Future research should examine whether the greater number of hospitals performing revascularization after CON removal raises expenditures due to the building of more facilities, or lowers expenditures due to enhanced price competition.

Assessing changes in high-volume hospital use: hospitals, payers, and aggregate volume trends

The relationship between higher procedure volumes and medical outcomes has generated recommendations for greater use of high-volume hospitals, with research and advocacy on this issue intensifying during the 1990s. Despite this interest, the trends presented here showed only limited changes between 1995 and 2002. For a number of services, less than half of patients received care at high-volume hospitals, and for several services, there was a surprising decline in the proportion at high-volume hospitals. Trends in the rate of high-volume hospital use appeared to be associated with trends in aggregate volume, at the same time that there were only modest changes in either patient use of high-volume hospitals or the number of hospitals offering these services. These trends suggested the importance of research on factors that affect patient choices, hospital decisions, and payer incentives concerning hospital use, especially in the context of declining aggregate procedure volumes.

Cardiac Certificate of Need regulations and the availability and use of revascularization services

BACKGROUND

Many states enforce Certificate of Need (CON) regulations for cardiac procedures, but little is known about how CON affects utilization. We assessed the association between cardiac CON regulations, availability of revascularization facilities, and revascularization rates.

METHODS

We determined when state cardiac CON regulations were active and obtained data for Medicare beneficiaries > or = 65 years old who received coronary artery bypass graft surgery (CABG) or a percutaneous coronary intervention (PCI) between 1989 and 2002. We compared the number of hospitals performing revascularization and patient utilization in states with and without CON regulations, and in states which discontinued CON regulations during 1989 to 2002.

RESULTS

Each year, the per capita number of hospitals performing CABG and PCI was higher in states without CON (3.7 per 100,000 elderly for CABG, 4.5 for PCI in 2002), compared with CON states (2.5 for CABG, 3.0 for PCI in 2002). Multivariate regressions that adjusted for market and population characteristics found no difference in CABG utilization rates between states with and without CON (P = .7). However, CON was associated with 19.2% fewer PCIs per 1000 elderly (P = .01), equivalent to 322,526 fewer PCIs for 1989 to 2002. Among most states that discontinued CON, the number of hospitals performing PCI rose in the mid 1990s, but there were no consistent trends in the number of hospitals performing CABG or in PCIs or CABGs per capita.

CONCLUSIONS

Certificate of Need restricts the number of cardiac facilities, but its effect on utilization rates may vary by procedure.

Does certificate of need affect cardiac outcomes and costs?

Several U.S. states enforce Certificate of Need (CON) regulations, which limit the number of hospitals performing open heart surgery or coronary angioplasty. CON regulations were intended to restrain cost growth and improve quality of care. This study compares mortality rates and costs for cardiac care in states with and without CON. CON appears to raise hospital procedure volume and lower the average cost of care. However, CON is associated with little reduction in inpatient mortality, and it may lead hospitals to operate on more patients than they would otherwise. The claimed welfare benefits of CON regulations require careful reconsideration.

Certificate of Need Regulation and Cardiac Catheterization Appropriateness After Acute Myocardial Infarction

BACKGROUND

Certificate of need (CON) regulation was introduced to control healthcare costs and improve quality of care in part by limiting the number of facilities providing complex medical care. Our objective was to examine whether rates of appropriate cardiac catheterization after admission for acute myocardial infarction varied between states with and without CON regulation of cardiac catheterization.

METHODS AND RESULTS

We performed a retrospective analysis of chart-abstracted data for 137,279 Medicare patients admitted for acute myocardial infarction between 1994 and 1996 at 4179 US acute-care hospitals. Using 3-level hierarchical generalized linear modeling adjusted for patient sociodemographic and clinical characteristics and physician and hospital characteristics, we compared catheterization rates within 60 days of admission for states (and the District of Columbia) with (n=32) and without (n=19) CON regulation in the full cohort and stratified by catheterization appropriateness. Appropriateness was categorized as strongly, equivocally, or weakly indicated. We found CON regulation was associated with a borderline-significant lower rate of catheterization overall (45.8% versus 46.5%; adjusted risk ratio [RR] 0.91, 95% confidence interval 0.82 to 1.00, P=0.06). After stratification by appropriateness, CON regulation was not associated with a significantly lower rate of catheterization among 63,823 patients with strong indications (49.9% versus 50.3%; adjusted RR 0.94, 95% confidence interval 0.86 to 1.02, P=0.17). However, CON regulation was associated with significantly lower rates of catheterization among 65,077 patients with equivocal indication (45.0% versus 46.0%; adjusted RR 0.88, 95% confidence interval 0.78 to 1.00, P=0.05) and among 8379 patients with weak indications (19.8% versus 21.8%; adjusted RR 0.84, 95% confidence interval 0.71 to 0.98, P=0.04). Associations were weakened substantially after adjustment for hospital coronary artery bypass graft surgery or cardiac catheterization capability.

CONCLUSIONS

CON regulation was associated with modestly lower rates of equivocally and weakly indicated cardiac catheterization after admission for acute myocardial infarction, but no significant differences existed in rates of strongly indicated catheterization.

Contemporary Impact of State Certificate-of-Need Regulations for Cardiac Surgery

Background— Prior research using administrative data associated certificate-of-need (CON) regulation for open heart surgery with higher hospital coronary artery bypass grafting (CABG) volume and lower CABG operative mortality rates in elderly patients. It is unclear whether these findings apply in a general population and after controlling for detailed clinical characteristics and region.

Methods and Results— Using the Society of Thoracic Surgeons’ (STS) National Cardiac Surgery Database, we examined isolated CABG surgery volume, operative mortality, and the composite end point of operative mortality or major morbidity for the years 2000 to 2003. The presence of CON regulations for open heart surgery was ascertained from the National Directory of the American Health Policy Association and by contacting CON administrators. Results were analyzed nationally, by state, and by region (West, Northeast, Midwest, South) and were adjusted for clinical factors and both population density and region with mixed-effects hierarchical logistic regression models. During 2000 to 2003, there were 314 710 isolated CABG surgeries performed at 294 STS hospitals in CON states (n=27, including Washington, DC) and 280 512 procedures at 343 STS hospitals in non-CON states (n=24). Patient clinical characteristics were similar among CON and non-CON hospitals. States with CON regulations tended to have higher population densities and had significantly higher median hospital annual CABG volumes in each of the years 2000 to 2003 ( P <0.005). This difference remained significant after adjustment for region and population density. Operative mortality was 2.52% for CON versus 2.62% for non-CON states ( P =0.32). There was a significant association between CON law and operative mortality in the South. After adjustment for patient risk factors and region, there was a marginally significant reduction of mortality risk in states with CON regulation (adjusted OR 0.92, 95% CI 0.86 to 1.00). However, this difference was not statistically significant when a revised model accounted for random state effects. Similar volume and outcomes results were seen when the analysis was repeated with data from the national Medicare database.

Conclusions— CON states have significantly higher hospital CABG surgery volumes but similar mortality compared with non-CON states. CON regulation alone is not a sufficient mechanism to ensure quality of care for CABG surgery.

Certificate-of-Need Regulation in Outpatient Surgery and Specialty Care: Implications for Plastic Surgeons

For plastic surgeons, independent development of outpatient surgical centers and specialty facilities is becoming increasingly common. These facilities serve as important avenues not only for increasing access and efficiency but in maintaining a sustainable, competitive specialty advantage. Certificate of Need regulation represents a major hurdle to plastic surgeons who attempt to create autonomy in this fashion. At the state level, Certificate of Need programs were initially established in an effort to reduce health care costs by preventing unnecessary capital outlays for facility expansion (i.e., managing supply of health care resources) in addition to assisting with patient safety and access to care. The purpose of this study was to examine the effect of Certificate of Need regulations on health care costs, patient safety, and access to care and to discuss specific implications of these regulations for plastic surgeons. Within Certificate of Need states, these regulations have done little, if anything, to control health care costs or affect patient safety. Presently, Certificate of Need effects coupled with recent provisions in the Medicare Modernization Act banning development of specialty hospitals may restrict patient access to ambulatory surgical and specialty care. For the plastic surgeon, these effects not only act as an economic barrier to entry but can threaten the efficiencies gained from providing surgical care in an ambulatory setting. An appreciation of these effects is critical to maintaining specialty autonomy and access to fiscal policy.

Cardiac revascularization in specialty and general hospitals

BACKGROUND

The emergence of specialty hospitals focusing on narrow procedural areas has generated controversy, although little is known about their quality.

METHODS

We conducted a retrospective cohort study of 42,737 Medicare beneficiaries who underwent percutaneous coronary intervention (PCI) and 26,274 who underwent coronary-artery bypass grafting (CABG) during 2000 and 2001 in specialty cardiac hospitals (15 for PCI and 15 for CABG) and general hospitals (82 for PCI and 75 for CABG) in the same markets. Administrative data were used to compare patients' characteristics, hospital procedural volumes, and patient outcomes.

RESULTS

Patients undergoing PCI or CABG in specialty hospitals were less likely to have coexisting conditions than those being treated at general hospitals and were less likely to have had an acute myocardial infarction (P<0.001). The better health of the patients at specialty hospitals than of those at general hospitals was reflected by the lower mean predicted risk of death (2.1 percent vs. 3.1 percent for PCI and 5.0 percent vs. 5.8 percent for CABG; P<0.001 for each comparison). Mean volumes of PCI and CABG procedures in 2000 and 2001 were higher in specialty hospitals than in general hospitals (799 vs. 375 PCI procedures, P<0.001; and 571 vs. 236 CABG procedures, P<0.001). The unadjusted rate of death during the index hospitalization or within 30 days after admission was lower in specialty hospitals than in general hospitals (2.1 percent vs. 3.2 percent for PCI and 4.7 percent vs. 6.0 percent for CABG; P<0.001 for both comparisons). In multivariate analyses adjusted for patients' characteristics, the odds ratio for death after PCI in specialty hospitals and general hospitals was similar (0.89; 95 percent confidence interval, 0.69 to 1.15; P=0.39), but the odds ratio for death after CABG was lower in specialty hospitals than in general hospitals (0.84; 95 percent confidence interval, 0.72 to 0.99; P=0.05). In stratified analyses comparing specialty and general hospitals with similar volumes, differences in mortality were not significant.

CONCLUSIONS

The lower unadjusted mortality rate after cardiac revascularization in specialty cardiac hospitals is accounted for by their healthier patients and higher procedural volumes.