Advance Care Planning and Treatment Intensity Before Death Among Black, Hispanic, and White Patients Hospitalized with COVID-19.

BACKGROUND: Black and Hispanic people are more likely to contract COVID-19, require hospitalization, and die than White people due to differences in exposures, comorbidity risk, and healthcare access. OBJECTIVE: To examine the association of race and ethnicity with treatment decisions and intensity for patients hospitalized for COVID-19. DESIGN: Retrospective cohort analysis of manually abstracted electronic medical records. PATIENTS: 7,997 patients (62% non-Hispanic White, 16% non-Black Hispanic, and 23% Black) hospitalized for COVID-19 at 135 community hospitals between March and June 2020 MAIN MEASURES: Advance care planning (ACP), do not resuscitate (DNR) orders, intensive care unit (ICU) admission, mechanical ventilation (MV), and in-hospital mortality. Among decedents, we classified the mode of death based on treatment intensity and code status as treatment limitation (no MV/DNR), treatment withdrawal (MV/DNR), maximal life support (MV/no DNR), or other (no MV/no DNR). KEY RESULTS: Adjusted in-hospital mortality was similar between White (8%) and Black patients (9%, OR=1.1, 95% CI=0.9-1.4, p=0.254), and lower among Hispanic patients (6%, OR=0.7, 95% CI=0.6-1.0, p=0.032). Black and Hispanic patients were significantly more likely to be treated in the ICU (White 23%, Hispanic 27%, Black 28%) and to receive mechanical ventilation (White 12%, Hispanic 17%, Black 16%). The groups had similar rates of ACP (White 12%, Hispanic 12%, Black 11%), but Black and Hispanic patients were less likely to have a DNR order (White 13%, Hispanic 8%, Black 7%). Among decedents, there were significant differences in mode of death by race/ethnicity (treatment limitation: White 39%, Hispanic 17% (p=0.001), Black 18% (p<0.0001); treatment withdrawal: White 26%, Hispanic 43% (p=0.002), Black 28% (p=0.542); and maximal life support: White 21%, Hispanic 26% (p=0.308), Black 36% (p<0.0001)). CONCLUSIONS: Hospitalized Black and Hispanic COVID-19 patients received greater treatment intensity than White patients. This may have simultaneously mitigated disparities in in-hospital mortality while increasing burdensome treatment near death.

Readmission Rates and Skilled Nursing Facility Utilization After Major Inpatient Surgery.

BACKGROUND: There is widespread interest in reducing use of postacute care (ie, care after hospital discharge) following major surgery, provided that such reductions do not worsen quality outcomes such as readmission rates. OBJECTIVES: To describe the association between changes in skilled nursing facility (SNF) use and changes in readmission rates after surgery. RESEARCH DESIGN: This was a observational study. SUBJECTS: Fee-for-service Medicare beneficiaries undergoing coronary artery bypass grafting (CABG) or total hip replacement (THR) from 2008 to 2013. MEASURES: Primary exposure was risk-adjusted SNF use initiated 0-2 days after hospital discharge, and the primary outcome was risk-adjusted readmission rates from 3 to 30 days after discharge. RESULTS: Among 176,994 patients who underwent CABG at 804 hospitals and 233,955 patients who underwent THR at 1220 hospitals, hospital-level SNF utilization increased after CABG (16.4%-19.0%, P=0.001) and THR (40.8%-45.5%, P<0.001), from 2008 to 2013. Hospital readmission rates decreased for CABG (14.7%-12.7%, P<0.001) but did not change for THR (4.9%-4.8%, P=0.55), from 2008 to 2013. However, there was wide variation in hospital-level change in readmission rates. After adjusting for hospital characteristics and baseline readmission rates, there was no statistically significant association between change in SNF use and change in readmission rates (0.017 and 0.011 percentage point increase in SNF use for every one percentage point increase in readmission rates for CABG and THR respectively, P=0.58 and 0.32). CONCLUSIONS: Changes in use of postacute care after THR and CABG have not been associated with changes in readmission rates.

Identifying Natural Alignments Between Ambulatory Surgery Centers and Local Health Systems: Building Broader Communities of Surgical Care.

OBJECTIVE: To develop and compare methods for identifying natural alignments between ambulatory surgery centers (ASCs) and hospitals that anchor local health systems. MEASURES: Using all-payer data from Florida's State Ambulatory Surgery and Inpatient Databases (2005-2009), we developed 3 methods for identifying alignments between ASCS and hospitals. The first, a geographic proximity approach, used spatial data to assign an ASC to its nearest hospital neighbor. The second, a predominant affiliation approach, assigned an ASC to the hospital with which it shared a plurality of surgeons. The third, a network community approach, linked an ASC with a larger group of hospitals held together by naturally occurring physician networks. We compared each method in terms of its ability to capture meaningful and stable affiliations and its administrative simplicity. RESULTS: Although the proximity approach was simplest to implement and produced the most durable alignments, ASC surgeon's loyalty to the assigned hospital was low with this method. The predominant affiliation and network community approaches performed better and nearly equivalently on these metrics, capturing more meaningful affiliations between ASCs and hospitals. However, the latter's alignments were least durable, and it was complex to administer. CONCLUSIONS: We describe 3 methods for identifying natural alignments between ASCs and hospitals, each with strengths and weaknesses. These methods will help health system managers identify ASCs with which to partner. Moreover, health services researchers and policy analysts can use them to study broader communities of surgical care.

Surgical skill and complication rates after bariatric surgery.

BACKGROUND: Clinical outcomes after many complex surgical procedures vary widely across hospitals and surgeons. Although it has been assumed that the proficiency of the operating surgeon is an important factor underlying such variation, empirical data are lacking on the relationships between technical skill and postoperative outcomes. METHODS: We conducted a study involving 20 bariatric surgeons in Michigan who participated in a statewide collaborative improvement program. Each surgeon submitted a single representative videotape of himself or herself performing a laparoscopic gastric bypass. Each videotape was rated in various domains of technical skill on a scale of 1 to 5 (with higher scores indicating more advanced skill) by at least 10 peer surgeons who were unaware of the identity of the operating surgeon. We then assessed relationships between these skill ratings and risk-adjusted complication rates, using data from a prospective, externally audited, clinical-outcomes registry involving 10,343 patients. RESULTS: Mean summary ratings of technical skill ranged from 2.6 to 4.8 across the 20 surgeons. The bottom quartile of surgical skill, as compared with the top quartile, was associated with higher complication rates (14.5% vs. 5.2%, P<0.001) and higher mortality (0.26% vs. 0.05%, P=0.01). The lowest quartile of skill was also associated with longer operations (137 minutes vs. 98 minutes, P<0.001) and higher rates of reoperation (3.4% vs. 1.6%, P=0.01) and readmission (6.3% vs. 2.7%) (P<0.001). CONCLUSIONS: The technical skill of practicing bariatric surgeons varied widely, and greater skill was associated with fewer postoperative complications and lower rates of reoperation, readmission, and visits to the emergency department. Although these findings are preliminary, they suggest that peer rating of operative skill may be an effective strategy for assessing a surgeon's proficiency.

Mortality Among Older Adults Before Versus After Hospital Transition to Intensivist Staffing.

BACKGROUND: A large body of research suggests that hospitals with intensive care units staffed by board-certified intensivists have lower mortality rates than those that do not. OBJECTIVE: To determine whether hospitals can reduce their mortality by adopting an intensivist staffing model. DESIGN: Retrospective, longitudinal study using 2003-2010 Medicare data and the Leapfrog Group Hospital surveys. SETTING AND PATIENTS: In total, 2,916,801 Medicare patients at 488 US hospitals. MEASUREMENTS: We studied 30-day and in-hospital mortality among patients with several common medical and surgical conditions. We first compared risk-adjusted mortality rates of 3 groups of hospitals: those that were intensivist staffed throughout this time period, those that were not intensivist staffed, and those that transitioned to intensivist staffing somewhere during the period. We then examined rates of mortality improvement within each of the 3 groups and used difference-in-differences techniques to assess the independent effect of intensivist staffing among the subset of hospitals that transitioned. RESULTS: Hospitals with intensivist staffing at the beginning of our study period had lower mortality rates than those without. However, hospitals that adopted intensivist staffing during the study period did not substantially improve their mortality rates. In our difference-in-differences analysis, there was no significant independent improvement in mortality after transitioning to intensivist staffing either overall [relative risk (RR), 0.96; 95% confidence interval (CI), 0.90-1.02] or in the medical (RR, 0.95; 95% CI, 0.89-1.02) or surgical populations (RR, 0.97; 95% CI, 0.84-1.10). LIMITATIONS: Risk adjustment was based on administrative data. Categorization of exposure was by survey response at the hospital level. CONCLUSIONS: Adoption of an intensivist staffing model was not associated with improved mortality in Medicare beneficiaries. These findings suggest that the lower mortality rates previously observed at hospitals with intensivist staffing may be attributable to other factors.

Impact of Surgical Quality Improvement on Payments in Medicare Patients.

OBJECTIVE: To examine the financial impact of quality improvement using Medicare payment data. BACKGROUND: Demonstrating a business case for quality improvement--that is, that fewer complications translates into lower costs--is essential to justify investment in quality improvement. Prior research is limited to cross-sectional studies showing that patients with complications have higher costs. We designed a study to better evaluate the relationship between payments and complications by using quality improvement itself as a measured outcome. METHODS: We used national Medicare data for patients undergoing general (n = 1,485,667) and vascular (n = 531,951) procedures. We calculated hospitals' rates of serious complications in 2 time periods: 2003-2004 and 2009-2010. We sorted hospitals into quintiles by the change in complication rates across these time periods. Costs were assessed using price-standardized Medicare payments, and regression analyses used to determine the average change in payments over time. RESULTS: There was significant change in serious complication rates across the 2 time periods. The top 20% of hospitals demonstrated a 38% decrease (14.3% vs 11.6%, P < 0.001) in complications; in contrast the bottom 20% demonstrated a 25% increase (11.1% vs 16.5%, P < 0.001). There was a strong relationship between quality improvement and payments. The top hospitals reduced their payments by $1544 per patient (95% confidence interval: $1334-1755), whereas the bottom of hospitals had no significant change (average $67 increase, 95% confidence interval: -$123 to $258). CONCLUSIONS: Hospitals that reduced their complications over time had significant reductions in Medicare payments. This demonstrates that payers are clearly incentivized to invest in quality improvement.

Assessing the reach of health reform to outpatient surgery with social network analysis.

OBJECTIVE: To assess the proportion of outpatient surgery currently delivered in ambulatory surgery centers (ASCs) unconnected to nearby hospitals. BACKGROUND: The ASC as a site for outpatient surgery represents one of the fastest growing sectors in health care. Because most are freestanding, ASCs may have little connection to local health systems, possibly placing them outside health reform's reach. METHODS: Using all-payer data from Florida (2005-2009), we identified all ASCs and hospitals active in the state. Using the tools of social network analysis, we then measured each ASC's strength of connection to nearby hospitals on the basis of the number of surgeons shared between facilities. Finally, we determined the proportion of all procedures and charges accounted for by (1) ASCs that are strongly connected to their local health system, (2) those that are weakly connected, and (3) those that are unconnected. RESULTS: Of the 1.4 million procedures performed in Florida ASCs each year, fewer than 250,000 occur at unconnected and weakly connected ASCs. Put differently, 83% of the $4.3 billion in charges for ASC-based care originate from facilities that have substantial integration with their local health system. Although weakly and strongly connected ASCs are similar from an organizational perspective, unconnected ones tend to focus on a single specialty (P = 0.026) and are staffed by fewer physicians (P = 0.013). Furthermore, there is a trend toward fewer unconnected ASCs over time (P = 0.080). CONCLUSIONS: Most ASCs are strongly connected to their local health system. Thus, efforts to constrain spending should target population-based rates of surgery, not unconnected ASCs.

Time-to-readmission and Mortality After High-risk Surgery.

OBJECTIVES: To determine if mortality varies by time-to-readmission (TTR). BACKGROUND: Although readmissions reduction is a national health care priority, little progress has been made toward understanding why only some readmissions lead to adverse outcomes. METHODS: In this retrospective cross-sectional cohort analysis, we used 2005-2009 Medicare data on beneficiaries undergoing colectomy, lung resection, or coronary artery bypass grafting (n = 1,033,255) to created 5 TTR groups: no 30-day readmission (n = 897,510), less than 6 days (n = 44,361), 6 to 10 days (n = 31,018), 11 to 15 days (n = 20,797), 16 to 20 days (n = 15,483), or more than 21 days (n = 24,086). Our analyses evaluated TTR groups for differences in risk-adjusted mortality (30, 60, and 90 days) and complications during the index admission. RESULTS: Increasing TTR was associated with a stepwise decline in mortality. For example, 90-day mortality rates in patients readmitted between 1 and 5 days, 6 and 10 days, and 11 and 15 days were 12.6%, 11.4%, and 10.4%, respectively (P < 0.001). Compared to nonreadmitted patients, the adjusted odds ratios (and 95% confidence intervals) were 4.88 (4.72-5.05), 4.20 (4.03-4.37), and 3.81 (3.63-3.99), respectively. Similar patterns were observed for 30- and 60-day mortality. There were no sizable differences in complication rates for patients readmitted within 5 days versus after 21 days (24.8% vs 26.2%, P < 0.001). CONCLUSIONS: Surgical readmissions within 10 days of discharge are disproportionately common and associated with increased mortality independent of index complications. These findings suggest 10-day readmissions should be specially targeted by quality improvement efforts.

Variation in hospital mortality rates with inpatient cancer surgery.

OBJECTIVE: To elucidate clinical mechanisms underlying variation in hospital mortality after cancer surgery BACKGROUND: : Thousands of Americans die every year undergoing elective cancer surgery. Wide variation in hospital mortality rates suggest opportunities for improvement, but these efforts are limited by uncertainty about why some hospitals have poorer outcomes than others. METHODS: Using data from the 2006-2007 National Cancer Data Base, we ranked 1279 hospitals according to a composite measure of perioperative mortality after operations for bladder, esophagus, colon, lung, pancreas, and stomach cancers. We then conducted detailed medical record review of 5632 patients at 1 of 19 hospitals with low mortality rates (2.1%) or 30 hospitals with high mortality rates (9.1%). Hierarchical logistic regression analyses were used to compare risk-adjusted complication incidence and case-fatality rates among patients experiencing serious complications. RESULTS: The 7.0% absolute mortality difference between the 2 hospital groups could be attributed to higher mortality from surgical site, pulmonary, thromboembolic, and other complications. The overall incidence of complications was not different between hospital groups [21.2% vs 17.8%; adjusted odds ratio (OR) = 1.34, 95% confidence interval (CI): 0.93-1.94]. In contrast, case-fatality after complications was more than threefold higher at high mortality hospitals than at low mortality hospitals (25.9% vs 13.6%; adjusted OR = 3.23, 95% CI: 1.56-6.69). CONCLUSIONS: Low mortality and high mortality hospitals are distinguished less by their complication rates than by how frequently patients die after a complication. Strategies for ensuring the timely recognition and effective management of postoperative complications will be essential in reducing mortality after cancer surgery.

Differences between physician social networks for cardiac surgery serving communities with high versus low proportions of black residents.

BACKGROUND: Compared with white patients, black patients are more likely to undergo cardiac surgery at low-quality hospitals, even when they live closer to high-quality ones. Opportunities for organizational interventions to alleviate this problem remain elusive. OBJECTIVES: To explore physician isolation in communities with high proportions of black residents as a factor contributing to racial disparities in access to high-quality hospitals for cardiac surgery. RESEARCH DESIGN: Using national Medicare data (2008-2011), we mapped physician social networks at hospitals where coronary artery bypass grafting procedures were performed, measuring their degree of connectedness. We then fitted a series of multivariate regression models to examine for associations between physician connectedness and the proportion of black residents in the hospital service area (HSA) served by each network. MEASURES: Measures of physician connectedness (ie, repeat-tie fraction, clustering, and number of external ties). RESULTS: After accounting for regional differences in healthcare capacity, the social networks of physicians practicing in areas with more black residents varied in many important respects from those of HSAs with fewer black residents. Physicians serving HSAs with many black residents had a smaller number of repeated interactions with each other than those in other HSAs (P<0.001). When these physicians did interact, they tended to assemble in smaller groups of highly interconnected colleagues (P<0.001). They also had fewer interactions with physicians outside their immediate geographic area (P=0.048). CONCLUSIONS: Physicians in HSAs with many black residents are more isolated than those in HSAs with fewer black residents. This isolation may negatively impact on care coordination and information sharing. As such, planned delivery system reforms that encourage minorities to seek care within their established local networks may further exacerbate existing surgical disparities.

Comparing perioperative processes of care in high and low mortality centers performing pancreatic surgery.

BACKGROUND: Pancreatic surgery outcomes vary widely. We hypothesize that by comparing high and low mortality hospitals, we may identify differences in patient care impacting safety. METHODS: We sampled hospitals with very-low and very-high mortality (LMH; HMH) and conducted on-site chart reviews evaluating perioperative care practices for pancreatic operations. RESULTS: HMHs had an 11.6% mortality rate; LMHs 1.5%. Patients in HMHs had worse ASA classification (20.9% ASA Class 4/5 vs. 2.0%, P < 0.001) and comorbidity burden (55.3% with ≥ 1 comorbidity vs. 39.6%, P = 0.037). At HMHs, operations took longer (353.9 min vs. 313.7 min, P = 0.05), had higher blood loss (1,203.7 ml vs. 881.6 ml, P = 0.04), and patients underwent more transfusions (70.2% vs. 41.1%, P < 0.001). There were differences in anesthetic care: less invasive monitoring (76.1% vs. 93.1%, P < 0.001) and epidural pain management (22.5% vs. 62.9%, P < 0.001). Both cohorts had similar rates of VTE prophylaxis and SSI prevention compliance. CONCLUSION: High and low mortality hospitals both have high compliance with common quality measures; however, HMHs performed worse in other areas of perioperative care, indicating possible targets for quality improvement efforts.

Strategies for reducing regional variation in the use of surgery: a systematic review.

OBJECTIVE: To review the literature evaluating the effect of practice guidelines and decision aids on use of surgery and regional variation. BACKGROUND: The use of surgical procedures varies widely across geographic regions. Although practice guidelines and decision aids have been promoted for reducing variation, their true effectiveness is uncertain. METHODS: Studies evaluating the influence of clinical practice guidelines or consensus statements, shared decision making and decision aids, or provider feedback of comparative utilization, on rates of surgical procedures were identified through literature searches of Ovid MEDLINE, EMBASE, and Web of Science. RESULTS: A total of 1946 studies were identified and 27 were included in the final review. Of the 12 studies evaluating implementation of guidelines, 6 reported a significant effect. Those examining overall population-based rates had mixed effects, but all studies evaluating procedure choice described at least a small increase in use of recommended therapy. Three of 5 studies examining the effect of guidelines on regional variation reported a significant reduction after dissemination. Of the 15 studies examining decision aids, 5 revealed significant effects. Many studies of decision aids reported decreases in population-based procedure rates. Nearly all studies evaluating the impact of decision aids on procedure choice reported increases in rates of less invasive procedures. Only one study of decision aids assessed changes in regional variation and found mixed results. CONCLUSIONS: Both practice guidelines and decision aids have been proven effective in many clinical contexts. Expanding the clinical scope of these tools and eliminating barriers to implementation will be essential to further efforts directed toward reducing regional variation in the use of surgery.

Hospital volume and operative mortality in the modern era.

OBJECTIVE: To determine whether the relationship between hospital volume and mortality has changed over time. BACKGROUND: It is generally accepted that hospital volume is associated with mortality in high-risk procedures. However, as surgical safety has improved over the last decade, recent evidence has suggested that the inverse relationship has diminished or been eliminated. METHODS: Using national Medicare claims data from 2000 through 2009, we examined mortality among 3,282,127 patients who underwent 1 of 8 gastrointestinal, cardiac, or vascular procedures. Hospitals were stratified into quintiles of operative volume. Using multivariable logistic regression models to adjust for patient characteristics, we examined the relationship between hospital volume and mortality, and assessed for changes over time. We performed sensitivity analyses using hierarchical logistic regression modeling with hospital-level random effects to confirm our results. RESULTS: Throughout the 10-year period, a significant inverse relationship was observed in all procedures. In 5 of the 8 procedures studied, the strength of the volume-outcome relationship increased over time. In esophagectomy, for example, the adjusted odds ratio of mortality in very low volume hospitals compared to very high volume hospitals increased from 2.25 [95% confidence interval (CI): 1.57-3.23] in 2000-2001 to 3.68 (95% CI: 2.66-5.11) in 2008-2009. Only pancreatectomy showed a notable decrease in strength of the relationship over time, from 5.83 (95% CI: 3.64-9.36) in 2000-2001, to 3.08 (95% CI: 2.07-4.57) in 2008-2009. CONCLUSIONS: For all procedures examined, higher volume hospitals had significantly lower mortality rates than lower volume hospitals. Despite recent improvements in surgical safety, the strong inverse relationship between hospital volume and mortality persists in the modern era.

Does pay-for-performance improve surgical outcomes? An evaluation of phase 2 of the Premier Hospital Quality Incentive Demonstration.

OBJECTIVE: We sought to determine whether the changes in incentive design in phase 2 of Medicare's flagship pay-for-performance program, the Premier Hospital Quality Incentive Demonstration (HQID), reduced surgical mortality or complication rates at participating hospitals. BACKGROUND: The Premier HQID was initiated in 2003 to reward high-performing hospitals. The program redesigned its incentive structure in 2006 to also reward hospitals that achieved significant improvement. The impact of the change in incentive structure on outcomes in surgical populations is unknown. METHODS: We examined discharge data for patients who underwent coronary artery bypass (CABG), hip replacement, and knee replacement at Premier hospitals and non-Premier hospitals in Hospital Compare from 2003 to 2009 in 12 states (n = 861,411). We assessed the impact of incentive structural changes in 2006 on serious complications and 30-day mortality. In these analyses, we adjusted for patient characteristics using multiple logistic regression models. To account for improvement in outcomes over time, we used difference-in-difference techniques that compare trends in Premier versus non-Premier hospitals. We repeated our analyses after stratifying hospitals into quintiles according to risk-adjusted mortality and serious complication rates. RESULTS: After restructuring incentives in 2006 in Premier hospitals, there were lower risk-adjusted mortality and complication rates for both cardiac and orthopedic patients. However, after accounting for temporal trends in non-Premier hospitals, there were no significant improvements in mortality for CABG [odds ratio (OR) = 1.09; 95% confidence interval (CI), 0.92-1.28] or joint replacement (OR = 0.81; 95% CI, 0.58-1.12). Similarly, there were no significant improvements in serious complications for CABG (OR = 1.05; 95% CI, 0.97-1.14) or joint replacement (OR = 1.12; 95% CI, 1.01-1.23). Analysis of the "worst" quintile hospitals that were targeted in the incentive structural changes also did not reveal a change in mortality [(OR = 1.01; 95% CI, 0.78-1.32) for CABG and (OR = 0.96; 95% CI, 0.22-4.26) for joint replacement] or serious complication rates [(OR = 1.08; 95% CI, 0.88-1.34) for CABG and (OR = 0.92; 95% CI, 0.67-1.28) for joint replacement]. CONCLUSIONS: Despite recent enhancements to incentive structures, the Premier HQID did not improve surgical outcomes at participating hospitals. Unless significantly redesigned, pay-for-performance may not be a successful strategy to improve outcomes in surgery.

Understanding of regional variation in the use of surgery.

The use of common surgical procedures varies widely across regions. Differences in illness burden, diagnostic practices, and patient attitudes about medical intervention explain only a small degree of regional variation in surgery rates. Evidence suggests that surgical variation results mainly from differences in physician beliefs about the indications for surgery, and the extent to which patient preferences are incorporated into treatment decisions. These two components of clinical decision making help to explain the so-called surgical signatures of specific procedures, and why some consistently vary more than others. Variation in clinical decision making is, in turn, affected by broad environmental factors, including technology diffusion, supply of specialists, local training frameworks, financial incentives, and regulatory factors, which vary across countries. Better scientific evidence about the comparative effectiveness of surgical and non-surgical interventions could help to mitigate regional variation, but broader dissemination of shared decision aids will be essential to reduce variation in preference-sensitive disorders.

Strategies to reduce variation in the use of surgery.

Provision rates for surgery vary widely in relation to identifiable need, suggesting that reduction of this variation might be appropriate. The definition of unwarranted variation is difficult because the boundaries of acceptable practice are wide, and information about patient preference is lacking. Very little direct research evidence exists on the modification of variations in surgery rates, so inferences must be drawn from research on the alteration of overall rates. The available evidence has large gaps, which suggests that some proposed strategies produce only marginal change. Micro-level interventions target decision making that affects individuals, whereas macro-level interventions target health-care systems with the use of financial, regulatory, or incentivisation strategies. Financial and regulatory changes can have major effects on provision rates, but these effects are often complex and can include unintended adverse effects. The net effects of micro-level strategies (such as improvement of evidence and dissemination of evidence, and support for shared decision making) can be smaller, but better directed. Further research is needed to identify what level of variation in surgery rates is appropriate in a specific context, and how variation can be reduced where desirable.

Trends in hospital volume and operative mortality for high-risk surgery.

BACKGROUND: There were numerous efforts in the United States during the previous decade to concentrate selected surgical procedures in high-volume hospitals. It remains unknown whether referral patterns for high-risk surgery have changed as a result and how operative mortality has been affected. METHODS: We used national Medicare data to study patients undergoing one of eight different cancer and cardiovascular operations from 1999 through 2008. For each procedure, we examined trends in hospital volume and market concentration, defined as the proportion of Medicare patients undergoing surgery in the top decile of hospitals by volume per year. We used regression-based techniques to assess the effects of volume and market concentration on mortality over time, adjusting for case mix. RESULTS: Median hospital volumes of four cancer resections (lung, esophagus, pancreas, and bladder) and of repair of abdominal aortic aneurysm (AAA) rose substantially. Depending on the procedure, higher hospital volumes were attributable to an increasing number of cases nationwide, an increasing market concentration, or both. Hospital volumes rose slightly for aortic-valve replacement but fell for coronary-artery bypass grafting and carotid endarterectomy. Operative mortality declined for all eight procedures, ranging from a relative decline of 8% for carotid endarterectomy (1.3% mortality in 1999 and 1.2% in 2008) to 36% for AAA repair (4.4% in 1999 and 2.8% in 2008). Higher hospital volumes explained a large portion of the decline in mortality for pancreatectomy (67% of the decline), cystectomy (37%), and esophagectomy (32%), but not for the other procedures. CONCLUSIONS: Operative mortality with high-risk surgery fell substantially during the previous decade. Although increased market concentration and hospital volume have contributed to declining mortality with some high-risk cancer operations, declines in mortality with other procedures are largely attributable to other factors. (Funded by the National Institute on Aging.).