Perceptions of overlapping surgery in neurosurgery based on practice volume: A multi-institutional survey.

OBJECTIVE: Overlapping surgery, accepted by many as two distinct operations occurring at the same time but without coincident critical portions, has been said to improve patient access to surgical care. With recent controversy, some are opposed to this practice due to concerns regarding its safety. In this manuscript, we sought to investigate the perceptions of overlapping surgery among neurosurgical leadership and the association of these perceptions with neurosurgical case volume. PATIENTS AND METHODS: We conducted a self-administered survey of neurosurgery department chair and residency program directors of institutions participating in the Vizient Clinical Database/Resource (CDB/RM), an administrative database of 117 United States (US) medical centers and their 300 affiliated hospitals. We queried participants regarding yearly departmental case-volume, frequency of overlapping surgery in daily practice and the degree of overlapping they find acceptable. RESULTS: Of the 236 surveys disseminated, a total of 70 responses were received with a response rate of 29.7.%, which is comparable to previously reported response rates among neurosurgeons and other physicians. Our respondents consisted of 43 of 165 chairs (26.1.%) and 27 of 66 program directors (40.0.%) representing 64 unique hospitals/institutions out of 216 (29.6.%). Based on the responses to question involving case volume, we divided our responders into high volume hospitals (HVH) (n = 44; > 2000 cases per year) and low volume hospitals (LVH) (N = 26). More HVH were found to have frequent occurrence of overlapping surgery (50% weekly and 20.9.% daily vs LVH's 26.9.% weekly and 3.8.% daily, p = 0.003) and considered two overlapping surgeries without overlap of critical portion as acceptable (38.6.% vs 26.9.%, p = 0.10). CONCLUSIONS: Our survey results showed that neurosurgical departments with high-volume practices were more likely to practice overlapping surgery on a regular basis and to view it as an acceptable practice. The association between overlapping surgery and the volume-outcome relationship should be further evaluated.

Characterizing the spectrum of body mass index associated with severe postoperative pulmonary complications in children.

PURPOSE: While high body mass index (BMI) is a recognized risk factor for pulmonary complications in adults, its importance as a risk factor for complications following pediatric surgery is poorly described. We evaluated the association between BMI and severe pediatric perioperative pulmonary complications (PPCs). METHODS: In this retrospective cohort study, we evaluated pediatric patients (aged 2-17 years) undergoing elective procedures in the 2015 Pediatric National Surgical Quality Improvement Program (NSQIP-P). Severe PPCs were defined as either pneumonia/reintubation within 3 days of surgery, or pneumonia/reintubation as an index complication within 7 days. Univariate and multivariable logistic regression analyses adjusting for patient factors and surgical case-mix tested associations between BMI class-using the Centers for Disease Control age- and sex-dependent BMI percentiles-and severe PPCs. RESULTS: Among 40,949 patients, BMI class was distributed as follows: 2740 (6.7%) were underweight, 23,630 (57.7%) normal weight, 6161 (15.0%) overweight, and 8418 (20.6%) obese. Overweight BMI class was not associated with PPCs in univariate analyses, but became statistically significant after adjustment [OR 1.84 (95% CI 1.07-3.15), p = 0.03], and persisted across multiple adjustment approaches. Neither underweight [OR 1.01 (95% CI 0.53-1.94), p = 0.97] nor obesity [OR 1.10 (95% CI 0.63-1.94), p = 0.73] were associated with PPCs after adjustment. CONCLUSION: Overweight pediatric patients have an elevated, previously underappreciated risk of severe PPCs. Contrary to prior studies, the present study found no greater risk in obese children, perhaps due to bias, confounding, or practice migration from "availability bias". Findings from the present study, taken with prior work describing pulmonary risks of obesity, suggest that both obese and overweight children may be evaluated for tailored perioperative care to improve outcomes.

Intra-Operative Inspired Fraction of Oxygen and the Risk of Surgical Site Infections in Patients with Type 1 Surgical Incisions.

BACKGROUND: Whether the fraction of inspired oxygen (FIO2) influences the risk of surgical site infection (SSI) is controversial. The World Health Organization and the World Federation of Societies of Anesthesiologists offer conflicting recommendations. In this study, we evaluate simultaneously three different definitions of FIO2 exposure and the risk of SSI in a large surgical population. PATIENTS AND METHODS: Patients with clean (type 1) surgical incisions who developed superficial and deep organ/space SSI within 30 days after surgery from January 2003 through December 2012 in five surgical specialties were matched to specialty-specific controls. Fraction of inspired oxygen exposure was defined as (1) nadir FIO2, (2) percentage of operative time with FIO2 greater than 50%, and (3) cumulative hyperoxia exposure, calculated as the area under the curve (AUC) of FIO2 by time for the duration in which FIO2 greater than 50%. Stratified univariable and multivariable logistic regression models tested associations between FIO2 and SSI. RESULTS: One thousand two hundred fifty cases of SSI were matched to 3,248 controls. Increased oxygen exposure, by any of the three measures, was not associated with the outcome of any SSI in a multivariable logistic regression model. Elevated body mass index (BMI; 35+ vs. <25, odds ratio [OR] 1.78, 95% confidence interval [CI] 1.43-2.24), surgical duration (250+ min vs. <100 min, OR 1.93, 95% CI 1.48-2.52), diabetes mellitus (OR 1.37, 95% CI 1.13-1.65), peripheral vascular disease (OR 1.52, 95% CI 1.10-2.10), and liver cirrhosis (OR 2.48, 95% CI 1.53-4.02) were statistically significantly associated with greater odds of any SSI. Surgical sub-group analyses found higher intra-operative oxygen exposure was associated with higher odds of SSI in the neurosurgical and spine populations. CONCLUSION: Increased intra-operative inspired fraction of oxygen was not associated with a reduction in SSI. These findings do not support the practice of increasing FIO2 for the purpose of SSI reduction in patients with clean surgical incisions.

Same-Day Cancellation in Ambulatory Surgery: A Retrospective Review at a Large Academic Tertiary Referral Center.

Although ambulatory surgery offers patients convenience and reduced costs, same-day cancellation of ambulatory surgery negatively affects patient experiences and operational efficiency. We conducted a retrospective analysis to determine the frequency and reasons for same-day cancellations in an outpatient surgery center at a large academic tertiary referral center. Of 41 389 ambulatory surgical procedures performed, same-day cancellations occurred at a rate of 0.5% and were usually unforeseeable in nature. Focusing on foreseeable cancellations offers opportunities for enhanced patient satisfaction, improved quality of care, and systems-based practice improvements to mitigate cancellations related to areas such as scheduling or patient noncompliance.

Assessing the Safety of Overlapping Surgery at a Children's Hospital.

IMPORTANCE: Media reports have questioned the safety of overlapping surgical procedures, and national scrutiny has underscored the necessity of single-center evaluations of its safety; however, sample sizes are likely small. We compared the safety profiles of overlapping and nonoverlapping pediatric procedures at a single children's hospital and discussed methodological considerations of the evaluation. DATA AND DESIGN: Retrospective analysis of inpatient pediatric surgical procedures (January 2013 to September 2015) at a single pediatric referral center. Overlapping and nonoverlapping procedures were matched in an unbalanced manner (m:n) by procedure. Mixed models adjusting for Vizient-predicted risk, case-mix, and surgeon compared inpatient mortality and length of stay (LOS). RESULTS: Among 315 overlapping procedures, 256 (81.3%) were matched to 645 nonoverlapping procedures. There were 6 deaths in all. The adjusted odds ratio for mortality did not differ significantly between nonoverlapping and overlapping procedures (adjusted odds ratio = 0.94 vs overlapping; 95% CI, 0.02-48.5; P = 0.98). Wide confidence intervals were minimally improved with Bayesian methods (95% CI, 0.07-12.5). Adjusted LOS estimates were not clinically different by overlapping status (0.6% longer for nonoverlapping; 95% CI, 9.7% shorter to 12.2% longer; P = 0.91). Among the 87 overlapping procedures with the greatest overlap (≥60 min or ≥50% of operative duration), there were no deaths. CONCLUSIONS: The safety of overlapping and nonoverlapping surgical procedures did not differ at this children's center. These findings may not extrapolate to other centers. LOS or intraoperative measures may be more appropriate than mortality for safety evaluations due to low event rates for mortality.

Occupational Variation in End-of-Life Care Intensity.

BACKGROUND: End-of-life (EOL) care intensity is known to vary by secular and geographic patterns. US physicians receive less aggressive EOL care than the general population, presumably the result of preferences shaped by work-place experience with EOL care. OBJECTIVE: We investigated occupation as a source of variation in EOL care intensity. METHODS: Across 4 states, we identified 660 599, nonhealth maintenance organization Medicare beneficiaries aged ≥66 years who died between 2004 and 2011. Linking death certificates, we identified beneficiaries with prespecified occupations: nurses, farmers, clergy, mortuary workers, homemakers, first-responders, veterinary workers, teachers, accountants, and the general population. End-of-life care intensity over the last 6 months of life was assessed using 5 validated measures: (1) Medicare expenditures, rates of (2) hospice, (3) surgery, (4) intensive care, and (5) in-hospital death. RESULTS: Occupation was a source of large variation in EOL care intensity across all measures, before and after adjustment for sex, education, age-adjusted Charlson Comorbidity Index, race/ethnicity, and hospital referral region. For example, absolute and relative adjusted differences in expenditures were US$9991 and 42% of population mean expenditure ( P < .001 for both). Compared to the general population on the 5 EOL care intensity measures, teachers (5 of 5), homemakers (4 of 5), farmers (4 of 5), and clergy (3 of 5) demonstrated significantly less aggressive care. Mortuary workers had lower EOL care intensity (4 of 5) but small numbers limited statistical significance. CONCLUSION: Occupations with likely exposure to child development, death/bereavement, and naturalistic influences demonstrated lower EOL care intensity. These findings may inform patients and clinicians navigating choices around individual EOL care preferences.

Safety of Overlapping Surgery at a High-volume Referral Center.

OBJECTIVE: To compare safety profiles of overlapping and nonoverlapping surgical procedures at a large tertiary-referral center where overlapping surgery is performed. BACKGROUND: Surgical procedures are frequently performed as overlapping, wherein one surgeon is responsible for 2 procedures occurring at the same time, but critical portions are not coincident. The safety of this practice has not been characterized. METHODS: Primary analyses included elective, adult, inpatient surgical procedures from January 2013 to September 2015 available through University HealthSystem Consortium. Overlapping and nonoverlapping procedures were matched in an unbalanced manner (m:n) by procedure type. Confirmatory analyses from the American College of Surgeons-National Surgical Quality Improvement Program investigated elective surgical procedures from January 2011 to December 2014. We compared outcomes mortality and length of stay after adjustment for registry-predicted risk, case-mix, and surgeon using mixed models. RESULTS: The University HealthSystem Consortium sample included 10,765 overlapping cases, of which 10,614 (98.6%) were matched to 16,111 nonoverlapping procedures. Adjusted odds ratio for inpatient mortality was greater for nonoverlapping procedures (adjusted odds ratio, OR = 2.14 vs overlapping procedures; 95% confidence interval, CI 1.23-3.73; P = 0.007) and length of stay was no different (+1% for nonoverlapping cases; 95% CI, -1% to +2%; P = 0.50). In confirmatory analyses, 93.7% (3712/3961) of overlapping procedures matched to 5,637 nonoverlapping procedures. The 30-day mortality (adjusted OR = 0.69 nonoverlapping vs overlapping procedures; 95% CI, 0.13-3.57; P = 0.65), morbidity (adjusted OR = 1.11; 95% CI, 0.92-1.35; P = 0.27) and length of stay (-4% for nonoverlapping; 95% CI, -4% to -3%; P < 0.001) were not clinically different. CONCLUSIONS: These findings from administrative and clinical registries support the safety of overlapping surgical procedures at this center but may not extrapolate to other centers.

Hospital Rating Systems and Implications For Patient Travel to Better-rated Hospitals.

Publicly reported hospital ratings aim to encourage transparency, spur quality improvement, and empower patient choice. Travel burdens may limit patient choice, particularly for older adults (aged 65 years and more) who receive most medical care. For 3 major hospital ratings systems, we estimated travel burden as the additional 1-way travel distance to receive care at a better-rated hospital.Distances were estimated from publicly available data from the US Census, US News Top Hospitals, Society of Thoracic Surgeons composite rating for coronary artery bypass grafting (STS-CABG), and Centers for Medicare and Medicaid Services Hospital Consumer Assessment of Healthcare Providers and Services (HCAHPS).Hospitals were rated for HCAHPS (n = 4656), STS-CABG (n = 470), and US News Top Hospitals (n = 15). Older adults were commonly located within 25 miles of their closest HCAHPS hospital (89.6%), but less commonly for STS-CABG (62.9%). To receive care at a better-rated hospital, travel distances commonly exceeded 25 miles: HCAHPS (39.2%), STS-CABG (62.7%), and US News Top Hospital (85.2%). Additional 1-way travel distances exceeded 25 miles commonly: HCAHPS (23.7%), STS-CABG (36.7%), US News Top Hospitals (81.8%).Significant travel burden is common for older adults seeking "better" care and is an important limitation of current hospital ratings for empowering patient choice.

Intraoperative Hypothermia and Surgical Site Infections in Patients with Class I/Clean Wounds: A Case-Control Study.

BACKGROUND: Numerous surgical quality metrics focus on prevention of unintentional perioperative hypothermia due, in part, to the association between hypothermia and surgical site infections (SSI). However, few studies have comprehensively evaluated the relationship between these metrics and SSI. In this study, we evaluated individual components of 1 set of hypothermia metrics to determine their association with SSI. STUDY DESIGN: Patients with clean (class I) wounds who developed an SSI within 30 days after surgery, from January 2003 to December 2012, in 1 of 5 surgical specialties, were matched to specialty-specific controls without SSI. Stratified logistic regression models were used to assess the associations between (1) compliance with the Surgical Care Improvement Project (SCIP) Performance Measure, Surgery Patients with Perioperative Temperature Management (SCIP-Inf-10), overall and its components (maintenance of minimum body temperature and use of an active warming device) and SSI and (2) intraoperative hypothermia. RESULTS: In both univariate and adjusted analyses using adjusted odds ratios (OR), SCIP-Inf-10 compliance was not associated with SSI (composite compliance OR 0.89, 95% CI 0.63 to 1.24; temperature compliance OR 0.92, 95% CI 0.78 to 1.09; forced-air warming device compliance OR 0.95, 95% CI 0.76 to 1.19). Higher intraoperative nadir temperature (OR 1.19, 95% CI 1.05 to 1.35) was associated with SSI. Percent of time exposed to a temperature < 36°C (OR 0.98, 95% CI 0.96 to 1.01), and cumulative hypothermic exposure (°C*h <36°C) (OR 0.98, 95% CI 0.90 to 1.05) were not associated with SSI. CONCLUSIONS: Intraoperative hypothermia was not significantly associated with SSI. These results suggest that development of compliance metrics may not be an effective strategy for SSI reduction in class I surgical wounds.

Risk Prediction Accuracy Differs for Emergency Versus Elective Cases in the ACS-NSQIP.

BACKGROUND: Accurate risk estimation is essential when benchmarking surgical outcomes for reimbursement and engaging in shared decision-making. The greater complexity of emergency surgery patients may bias outcome comparisons between elective and emergency cases. OBJECTIVE: To test whether an established risk modelling tool, the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) predicts mortality comparably for emergency and elective cases. METHODS: From the ACS-NSQIP 2011-2012 patient user files, we selected core emergency surgical cases also common to elective scenarios (gastrointestinal, vascular, and hepato-biliary-pancreatic). After matching strategy for Common Procedure Terminology (CPT) and year, we compared the accuracy of ACS-NSQIP predicted mortality probabilities using the observed-to-expected ratio (O:E), c-statistic, and Brier score. RESULTS: In all, 56,942 emergency and 136,311 elective patients were identified as having a common CPT and year. Using a 1:1 matched sample of 37,154 emergency and elective patients, the O:E ratios generated by ACS-NSQIP models differ significantly between the emergency [O:E = 1.031; 95% confidence interval (CI) = 1.028-1.033] and elective populations (O:E = 0.79; 95% CI = 0.77-0.80, P < 0.0001) and the c-statistics differed significantly (emergency c-statistic = 0.927; 95% CI = 0.921-0.932 and elective c-statistic = 0.887; 95% CI = 0.861-0.912, P = 0.003). The Brier score, tested across a range of mortality rates, did not differ significantly for samples with mortality rates of 6.5% and 9% (eg, emergency Brier score = 0.058; 95% CI = 0.048-0.069 versus elective Brier score = 0.057; 95% CI = 0.044-0.07, P = 0.87, among 2217 patients with 6.5% mortality). When the mortality rate was low (1.7%), Brier scores differed significantly (emergency 0.034; 95% CI = 0.027-0.041 versus elective 0.016; 95% CI = 0.009-0.023, P value for difference 0.0005). CONCLUSION: ACS-NSQIP risk estimates used for benchmarking and shared decision-making appear to differ between emergency and elective populations.

Safety of Noncardiac Surgery in Patients With Hypertrophic Obstructive Cardiomyopathy at a Tertiary Care Center.

OBJECTIVES: This study's purpose was to review non-cardiac surgery (NCS) in patients with hypertrophic obstructive cardiomyopathy (HOCM) to examine perioperative management and quantify postoperative mortality and worsening heart failure. DESIGN: Retrospective review. SETTING: A single tertiary care center. PARTICIPANTS: The study included 57 adult patients with HOCM who underwent NCS from January 1, 1996, through January 31, 2014. INTERVENTIONS: Noncardiac surgery. MEASUREMENTS AND MAIN RESULTS: The authors identified 57 HOCM patients who underwent 96 NCS procedures. Vasoactive medications were administered to the majority of NCS patients. Three patients (3%) died within 30 days of NCS, but causes of death did not appear to be cardiac in nature. Death after NCS was not significantly associated with preoperative left ventricular ejection fraction (p = 0.2727) or peak instantaneous systolic resting gradient (0.8828), but was associated with emergency surgery (p = 0.0002). Three patients experienced worsening heart failure postoperatively, and this was significantly associated with preoperative New York Heart Association Class III-IV symptoms compared with I-II symptoms (p = 0.0008). CONCLUSIONS: HOCM patients safely can undergo NCS at multidisciplinary centers experienced in caring for these patients. The mortality rate in this study was less than that reported in the majority of other studies. Postoperative complications, including increasing heart failure, may occur, especially in patients with more severe preoperative cardiac symptoms.

Frequency and outcomes of severe hyperlactatemia after elective cardiac surgery.

BACKGROUND: Hyperlactatemia is relatively common in the cardiac surgical patient and is usually considered a marker of illness severity. The frequency and impact of severe hyperlactatemia after elective cardiac surgery has not been described, and prognosis may be different compared with that for other surgical or medical critically ill patient populations. METHODS: We conducted a retrospective study to evaluate the hospital course and outcomes of patients who developed severe postoperative hyperlactatemia (SPHL; lactate >10 mmol/L) after elective cardiac surgery, from January 1, 2008 to December 31, 2012, at a large, academic, tertiary referral center. RESULTS: Of 9580 cardiac surgical patients who met inclusion criteria, 121 (1.26%) developed SPHL. The most common cause was cardiogenic shock (53.8%). In-hospital mortality was 40.5% but varied widely based on the cause of the SPHL. All patients with definite mesenteric ischemia (n = 5) or extremity compartment syndrome (n = 6) at the time of SPHL died in the hospital. Forty patients (33.1%) were discharged to home, whereas 32 (26.4%) were discharge to a skilled-care facility. CONCLUSIONS: Severe postoperative hyperlactatemia is rare after elective cardiac surgery. Although this phenomenon continues to be associated with mortality, >50% of patients survived to hospital discharge, a more favorable prognosis, compared with other patient populations based on lactate levels alone. Important exceptions were patients who had extremity compartment syndrome or mesenteric ischemia, which were associated with in-hospital death in all cases. In all other etiologic groups, a substantial proportion of patients were discharged to home.

Hospital-level Variation in Secondary Complications After Surgery.

OBJECTIVES: To assess whether hospital rates of secondary complications could serve as a performance benchmark and examine associations with mortality. BACKGROUND: Failure to rescue (death after postoperative complication) is a challenging target for quality improvement. Secondary complications (complications after a first or "index" complication) are intermediate outcomes in the rescue process that may provide specific improvement targets and give us insight into how rescue fails. METHODS: We used American College of Surgeons' National Surgical Quality Improvement Program data (2008-2012) to define hospital rates of secondary complications after 5 common index complications: pneumonia, surgical site infection (SSI), urinary tract infection, transfusion/bleed events, and acute myocardial infarction (MI). Hospitals were divided into quintiles on the basis of risk- and reliability-adjusted rates of secondary complications, and these rates were compared along with mortality. RESULTS: A total of 524,860 patients were identified undergoing one of the 62 elective, inpatient operations. After index pneumonia, secondary complication rates varied from 57.99% in the highest quintile to 22.93% in the lowest [adjusted odds ratio (OR), 4.64; confidence interval (CI), 3.95-5.45). Wide variation was seen after index SSI (58.98% vs 14.81%; OR, 8.53; CI, 7.41-9.83), urinary tract infection (38.41% vs 8.60%; OR, 7.81; CI, 6.48-9.40), transfusion/bleeding events (27.14% vs 12.88%; OR, 2.54; CI, 2.31-2.81), and acute MI (64.45% vs 23.86%, OR, 6.87; CI, 5.20-9.07). Hospitals in the highest quintile had significantly greater mortality after index pneumonia (10.41% vs 6.20%; OR, 2.17; CI, 1.6-2.94), index MI (18.25% vs 9.65%; OR, 2.67; CI, 1.80-3.94), and index SSI (2.75% vs 0.82%; OR, 3.93; CI, 2.26-6.81). CONCLUSIONS: Hospital-level rates of secondary complications (failure to arrest complications) vary widely, are associated with mortality, and may be useful for quality improvement and benchmarking.

Anesthesia Care Transitions and Risk of Postoperative Complications.

BACKGROUND: A patient undergoing surgery may receive anesthesia care from several anesthesia providers. The safety of anesthesia care transitions has not been evaluated. Using unconditional and conditional multivariable logistic regression models, we tested whether the number of attending anesthesiologists involved in an operation was associated with postoperative complications. METHODS: In a cohort of patients undergoing elective colorectal surgical in an academic tertiary care center with a stable anesthesia care team model participating in the American College of Surgeons National Surgical Quality Improvement Program, using unconditional and conditional multivariable logistic regression models, we tested adjusted associations between numbers of attending anesthesiologists and occurrence of death or a major complication (acute renal failure, bleeding that required a transfusion of 4 units or more of red blood cells within 72 hours after surgery, cardiac arrest requiring cardiopulmonary resuscitation, coma of 24 hours or longer, myocardial infarction, unplanned intubation, ventilator use for 48 hours or more, pneumonia, stroke, wound disruption, deep or organ-space surgical-site infection, superficial surgical-site infection, sepsis, septic shock, systemic inflammatory response syndrome). RESULTS: We identified 927 patients who underwent elective colectomy of comparable surgical intensity. In all, 71 (7.7%) patients had major nonfatal complications or death. One anesthesiologist provided care for 530 (57%) patients, 2 anesthesiologists for 287 (31%), and 3 or more for 110 (12%). The number of attending anesthesiologists was associated with increased odds of postoperative complication (unadjusted odds ratio [OR] = 1.52, 95% confidence interval [CI] 1.18-1.96, P = 0.0013; adjusted OR = 1.44, 95% CI 1.09-1.91, P = 0.0106). In sensitivity analyses, occurrence of a complication was significantly associated with the number of in-room providers, defined as anesthesia residents and nurse anesthetists (adjusted OR = 1.39, 95% CI 1.01-1.92, P = 0.0446) and for all anesthesia providers (adjusted OR = 1.58, 95%CI 1.20-2.08, P = 0.0012). Findings persisted across multiple, alternative adjustments, sensitivity analyses, and conditional logistic regression with matching on operative duration. CONCLUSIONS: In our study, care by additional attending anesthesiologists and in-room providers was independently associated with an increased odds of postoperative complications. These findings challenge the assumption that anesthesia transitions are care neutral and not contributory to surgical outcomes.

Outcomes and Costs for Major Lung Resection in the United States: Which Patients Benefit Most From High-Volume Referral?

BACKGROUND: Accountable care organizations are designed to improve value by decreasing costs and maintaining quality. Strategies to maximize value are needed for high-risk surgery. We wanted to understand whether certain patient groups were differentially associated with better outcomes at high-volume hospitals in terms of quality and cost. METHODS: In all, 37,746 patients underwent elective major lung resection in 1,273 hospitals in the Nationwide Inpatient Sample from 2007 to 2011. Patients were stratified by hospital volume quartile and substratified by preoperative mortality risk, age, and chronic obstructive pulmonary disease status. Mortality was evaluated using clustered multivariable hierarchical logistic regression controlling for patient comorbidity, demographics, and procedure. Adjusted cost was evaluated using generalized linear models fit to a gamma distribution. RESULTS: Patients were grouped into volume quartiles based on cases per year (less than 21, 21 to 40, 40 to 78, and more than 78). Patient characteristics and procedure mix differed across quartiles. Overall, mortality decreased across volume quartiles (lowest 1.9% versus highest 1.1%, p < 0.0001). Patients aged more than 80 years were associated with greater absolute and relative mortality rates than patients less than 60 years old in highest volume versus lowest volume hospitals (age more than 80 years, 4.2% versus 1.3%, p < 0.0001, odds ratio 3.31, 95% confidence interval: 1.89 to 5.80; age less than 60 years, 1.0% versus 0.8%, p = 0.19, odds ratio 1.38, 95% confidence interval: 0.74 to 2.56). Patients with high preoperative risk (more than 75th percentile) were also associated with lower absolute mortality in high-volume hospitals. Adjusted costs were not significantly different across quartiles or patient strata. CONCLUSIONS: Older patients show a significantly stronger volume-outcome relationship than patients less than 60 years of age. Costs were equivalent across volume quartile and patient strata. Selective patient referral may be a strategy to improve outcomes for elderly patients undergoing lung resection.