Influence of national centralization of oesophagogastric cancer on management and clinical outcome from emergency upper gastrointestinal conditions.

BACKGROUND: In England in 2001 oesophagogastric cancer surgery was centralized. The aim of this study was to evaluate whether centralization of oesophagogastric cancer to high-volume centres has had an effect on mortality from different emergency upper gastrointestinal conditions. METHODS: The Hospital Episode Statistics database was used to identify patients admitted to hospitals in England (1997-2012). The influence of oesophagogastric high-volume cancer centre status (20 or more resections per year) on 30- and 90-day mortality from oesophageal perforation, paraoesophageal hernia and perforated peptic ulcer was analysed. RESULTS: Over the study interval, 3707, 12 441 and 56 822 patients with oesophageal perforation, paraoesophageal hernia and perforated peptic ulcer respectively were included. There was a passive centralization to high-volume cancer centres for oesophageal perforation (26·9 per cent increase), paraoesophageal hernia (19·5 per cent increase) and perforated peptic ulcer (23·0 per cent increase). Management of oesophageal perforation in high-volume centres was associated with a reduction in 30-day (HR 0·58, 95 per cent c.i. 0·45 to 0·74) and 90-day (HR 0·62, 0·49 to 0·77) mortality. High-volume cancer centre status did not affect mortality from paraoesophageal hernia or perforated peptic ulcer. Annual emergency admission volume thresholds at which mortality improved were observed for oesophageal perforation (5 patients) and paraoesophageal hernia (11). Following centralization, the proportion of patients managed in high-volume cancer centres that reached this volume threshold was 88·0 per cent for oesophageal perforation, but only 30·3 per cent for paraoesophageal hernia. CONCLUSION: Centralization of low incidence conditions such as oesophageal perforation to high-volume cancer centres provides a greater level of expertise and ultimately reduces mortality.

Case mix, quality and high-cost kidney transplant patients.

A better understanding of high-cost kidney transplant patients would be useful for informing value-based purchasing strategies by payers. This retrospective cohort study was based on the Medicare Provider Analysis and Review (MEDPAR) files from 2003 to 2006. The focus of this analysis was high-cost kidney transplant patients (patients that qualified for Medicare outlier payments and 30-day readmission payments). Using regression techniques, we explored relationships between high-cost kidney transplant patients, center-specific case mix, and center quality. Among 43 393 kidney transplants in Medicare recipients, 35.2% were categorized as high-cost patients. These payments represented 20% of total Medicare payments for kidney transplantation and exceeded $200 million over the study period. Case mix was associated with these payments and was an important factor underlying variation in hospital payments high-cost patients. Hospital quality was also a strong determinant of future Medicare payments for high-cost patients. Compared to high-quality centers, low-quality centers cost Medicare an additional $1185 per kidney transplant. Payments for high-cost patients represent a significant proportion of the total costs of kidney transplant surgical care. Quality improvement may be an important strategy for reducing the costs of kidney transplantation.

The effects of donor and recipient practices on transplant center finances.

Over the past several years we have noted a marked decrease in this profitability of our kidney transplant program. Our hypothesis is that this reduction in kidney transplant institutional profitability is related to aggressive donor and recipient practices. The study population included all adults with Medicare insurance who received a kidney transplant at our center between 1999 and 2005. Adopting the hospital perspective, multi-variate linear regression models to determine the independent effects of donor and recipient characteristics and era effects on total reimbursements and total hospital margin. We note statistically significant decreased medical center incremental margins in cases with ECDs (-$5887) and in cases of DGF (-4937). We also note an annual change in the medical center margin is independently associated with year and changes at a rate of -$5278 per year, related to both increasing costs and decreasing Medicare reimbursements. The financial loss associated with patient DGF and the use of ECD kidneys may resonate with other centers, and could hinder efforts to expand kidney transplantation within the United States. The Centers for Medicare and Medicaid Services (CMS) should consider risk-adjusted reimbursement for kidney transplantation.

The epidemiology of diagnosed pulmonary embolism and deep venous thrombosis in the elderly.

BACKGROUND: There are no studies that define the basic epidemiology of pulmonary embolism (PE) and deep venous thrombosis (DVT) in the elderly. This project was undertaken to provide that information. METHODS: We obtained all Medicare claims during the period 1986 through 1989 from a random 5% sample of US Medicare enrollees. By selecting codes used for diagnoses and treatment, we identified 7174 cases of PE and 8923 cases of DVT. These cohorts were analyzed to provide incidence by age, race, sex, and geographic location; frequency of invasive treatment; frequency of PE after treatment for DVT; frequency of recurrence of PE; and survival after diagnosis. RESULTS: Annual incidence rates per 1000 at age 65 to 69 years for PE and DVT were 1.3 and 1.8, respectively. Both rates increased steadily with age to 2.8 and 3.1 by age 85 to 89 years. For PE, women had lower rates than men (adjusted relative risk, 0.86; 95% confidence interval, 0.82 to 0.90), and blacks had higher rates than whites (adjusted relative risk, 1.25; 95% confidence interval, 1.15 to 1.36). For DVT, the associations with gender and race were weaker and in the opposite direction. Pulmonary embolectomy was done in 0.2% of cases of PE; interruption of the vena cava was done in 4.4% of cases of PE and in 2% of cases of DVT. Thrombectomy was done in 0.3% of all cases. Pulmonary embolism occurred in 1.7% of patients with DVT within 1 year of hospital discharge for initial treatment. The 1-year recurrence rate for PE was 8.0%. In-hospital mortality associated with PE and DVT was 21% and 3%, respectively. One-year mortality was 39% and 21%, respectively. CONCLUSIONS: Pulmonary embolism and DVT are common problems in the elderly. Both increase with age, but the effects of race and sex are small. Current treatment patterns appear to be effective in preventing both PE after DVT and recurrence of PE. Both are associated with substantial 1-year mortality, suggesting the need to understand the role of associated conditions as well as the indications for prophylaxis and the methods of treatment.

Cost-effectiveness of head CT in patients with lung cancer without clinical evidence of metastases.

OBJECTIVE: To estimate the cost-effectiveness of CT for detecting brain lesions in patients with lung cancer without clinical evidence of metastases. DESIGN: Decision analysis model comparing two different strategies for detecting brain metastases: brain CT routinely (CT-first) or brain CT only when patients develop neurologic signs and/or symptoms (CT-deferred). PATIENTS: Hypothetical cohort of patients with lung cancer with an unremarkable screening clinical evaluation for metastases. MEASUREMENTS: Net costs are calculated as the difference in costs between the two limbs of the decision tree. Net benefits are expressed as the difference in calculated years of life expectancy between the two strategies. Net costs are divided by net benefits, yielding the marginal cost per quality adjusted year of added life expectancy (C/QALY) for the CT-first strategy. RESULTS: In the baseline analysis, the C/QALY for the CT-first strategy is about $70,000. Improving the clinical evaluation as a screen for detecting brain metastases markedly increases the C/QALY. Increasing the cost of brain CT magnifies this effect. More effective treatment for asymptomatic brain metastases and better accuracy of CT for identifying resectable and unresectable brain metastases lower C/QALY. CONCLUSIONS: Although a threshold cost-effectiveness has not been defined for identifying "cost-effective" diagnostic procedures, the marginal C/QALY of the CT-first strategy is substantially higher than many accepted medical interventions. At current costs, the routine use of brain CT is not warranted in patients with lung cancer who have normal findings on a standardized clinical evaluation for metastases.

Rationing surgery: rules or constraints?

BACKGROUND: As U.S. health care expenditures climb, the need to set limits on surgery is becoming more generally accepted. If limits are necessary, how should they be established and by whom? This article considers two fundamental approaches, rules and constraints. RESULTS: With rules, payers or policymakers ration care by prioritizing and then restricting specific procedures. Although they have the advantage of explicitness, rules based on treatment prioritization are limited by patient heterogeneity and the lack of outcomes data necessary to rank many procedures. Rules are unambiguous and free the surgeon from the obligation to set limits, but they do not accommodate clinical judgment or patient preferences. With constraints, limits are set on surgical resources (e.g., the number and distribution of surgeons), but individual surgeons determine which procedures are provided to which patients. Although constraints are more feasible than rules, it is difficult to establish an "adequate" supply of surgical resources and to ensure that limits set by the individual surgeon are based on treatment efficacy. While preserving clinical autonomy, constraints require the surgeon to assume the responsibility of rationing care. CONCLUSIONS: Surgeons should consider carefully the approach to rationing that best serves their professional interests, their patients, and society.

Cost-effectiveness analysis in surgery.

BACKGROUND: With tighter constraints on health care spending, many recognize the need to identify and restrict clinical interventions that are not cost-effective. As a result, cost-effectiveness analysis is being used increasingly to assess the relative value of surgical interventions. METHODS AND RESULTS: We first present the general concept of cost-effectiveness analysis and review a recent study of carotid endarterectomy to demonstrate the technique. We next consider the classic application of cost-effectiveness analysis to resource-allocation decisions and use the Oregon Medicaid experiment to illustrate some potential problems with this approach. We then present the current role of cost-effectiveness analysis: informing decisions about individual interventions that are new, controversial, or in direct competition with an accepted alternative treatment. Finally, we review several limitations of the methods used to measure costs and benefits and discuss problems with the interpretation of cost-effectiveness studies. CONCLUSIONS: Cost-effectiveness analysis is a systematic approach to assessing the relative value of health care interventions. This technique is being used increasingly to frame clinical policy decisions in surgery. Because of this, surgeons need to understand cost-effectiveness analysis and be prepared to examine these studies critically.

Decision analysis in surgery.

BACKGROUND: The technique of decision analysis is often applied to clinical policy and economic issues in surgery. Because surgeons may be unfamiliar with such work, this article catalogues decision analysis studies in the surgical specialties. METHODS: We reviewed the medical literature (1966 to 1994) to identify surgical decision analysis studies and to assess trends over time. Each article was categorized according to the type of journal (surgical, other clinical, or technical) in which it was published and content, including surgical specialty, clinical topic, article focus (individual patient decision making, clinical policy, or cost-effectiveness), and primary findings. RESULTS: Publication rates of surgical decision analysis have increased dramatically over time. Of the 86 total studies only six were published before 1980. In contrast, 44 studies appeared between 1990 and 1994. Although 77% were published in nonsurgical journals, decision analyses have begun to appear more regularly in surgical forums. Studies addressing all of the surgical specialties were found, although more than one half addressed topics in general surgery (34%) or cardiothoracic surgery (22%). The most frequent topics were gallstones (11 articles), head and neck cancer (five articles), coronary artery disease (four articles), and cerebral arteriovenous malformations (four articles). Articles focusing on clinical policy (i.e., those assessing surgical efficacy for broad groups of patients) now account for large majority of published decision analyses. CONCLUSIONS: The use of decision analysis in surgery is growing steadily. Because decision analysis is being used to influence clinical policy, it is important for surgeons to be aware of these studies and to be able to review them critically.

Volume standards for high-risk surgical procedures: potential benefits of the Leapfrog initiative.

BACKGROUND: As part of a broader effort aimed at improving hospital safety, a large coalition of employers, the Leapfrog Group, will soon require hospitals caring for their employees to meet volume standards for 5 high-risk surgical procedures. We estimated the potential benefits of full nationwide implementation of these volume standards. METHODS. Using data from Nationwide Inpatient Sample and other sources, we first estimated the total number of each of the 5 procedures-coronary-artery bypass graft, abdominal aortic aneurysm repair, coronary angioplasty, esophagectomy, and carotid endarterectomy-performed each year in hospitals in US metropolitan areas. (Leapfrog exempts hospitals in rural areas to avoid access issues.) We then projected the effectiveness of volume standards (in terms of relative risks of mortality) for each procedure using data from a published structured literature review. RESULTS: With full implementation nationwide, the Leapfrog volume standards would save 2581 lives. Of the procedures, volume standards would save the most lives with coronary-artery bypass graft (1486), followed by abdominal aortic-aneurysm repair (464), coronary angioplasty (345), esophagectomy (168), and carotid endarterectomy (118). In our estimates of the number of lives saved, we considered assumptions about how many patients would be affected and the effectiveness of volume standards (ie, strength of underlying volume-outcome relationships with each procedure). CONCLUSIONS: If the Leapfrog volume standards are successfully implemented, employers and health-care purchasers could prevent many surgical deaths by requiring hospital volume standards for high-risk procedures.

Relationship between hospital volume and late survival after pancreaticoduodenectomy.

BACKGROUND: Several studies have reported lower perioperative mortality rates with pancreaticoduodenectomy at high-volume hospitals than at low-volume hospitals. We sought to determine whether volume is also related to survival after hospital discharge. METHODS: Using information from the Medicare claims database, we performed a retrospective cohort study of all 7229 patients over age 65 undergoing pancreaticoduodenectomy in the United States between 1992 and 1995. We divided the study population into approximate quartiles according to their hospital's average annual volume of pancreaticoduodenectomies in Medicare patients: very low (< 1/y), low (1-2/y, medium (2-5/y), and high (5+/y). To adjust for potentially confounding variables, we used a Cox proportional hazards model to examine relationships between hospital volume and mortality, our primary outcome measure. RESULTS: Overall, 3-year survival was higher at high-volume centers (37%) than at medium- (29%), low- (26%), and very low volume hospitals (25%) (log-rank P < .0001). After excluding perioperative deaths and adjusting for case-mix, patients undergoing surgery at high-volume hospitals remained less likely to experience late mortality than patients at very low volume centers (adjusted hazard ratio 0.69, 95% CI 0.62-0.76). Relationships between hospital volume and survival after discharge were not restricted to patients with cancer diagnoses; patients with benign disease had similar improvements in late survival after surgery at high-volume centers. CONCLUSIONS: Hospital volume strongly influences both perioperative risk and long-term survival after pancreaticoduodenectomy. Our data suggest that both patient selection and differences in quality of care may underlie better outcomes at high-volume referral centers.

Variation profiles of common surgical procedures.

BACKGROUND: Rates of many surgical procedures vary widely across both large and small geographic regions. Although variation in health care use has long been described, few studies have systematically compared variation profiles across surgical procedures. The goal of this study was to examine current patterns of regional variation in the rates of common surgical procedures. METHODS: The study population consisted of patients enrolled in Medicare in 1995, excluding those enrolled in risk-bearing health maintenance organizations. Patients ranged in age from 65 to 99 years. Using data from hospital discharge abstracts, we calculated rates of 11 common inpatient procedures for each of 306 US hospital referral regions (HRRs). To assess the relative variability of each procedure, we determined the number of low and high outlier regions (HRRs with rates < 50% or > 150% the national average) and the ratio of highest to lowest HRR rates. RESULTS: Procedures differed markedly in their variability. Rates of hip fracture repair, resection for colorectal cancer, and cholecystectomy varied only 1.9- to 2.9-fold across HRRs (0, 0, and 4 outlier regions, respectively). Coronary artery bypass grafting, transurethral prostatectomy, mastectomy, and total hip replacement had intermediate variation profiles, varying 3.5- to 4.7-fold across regions (8, 10, 16, and 17 outlier regions, respectively). Lower extremity revascularization, carotid endarterectomy, back surgery, and radical prostatectomy had the highest variation profiles, varying 6.5- to 10.1-fold across HRRs (25, 32, 39, and 56 outlier regions, respectively). CONCLUSIONS: Although the use of many surgical procedures varies widely across geographic areas, rates of "discretionary" procedures are most variable. To avoid potential overuse or underuse, efforts to increase consensus in clinical decision making should focus on these high variation procedures.

Effect of hospital volume on in-hospital mortality with pancreaticoduodenectomy.

BACKGROUND: Reports of better results at national referral centers than at low-volume community hospitals have prompted calls for regionalizing pancreaticoduodenectomy (the Whipple procedure). We examined the relationship between hospital volume and mortality with this procedure across all US hospitals. METHODS: Using information from the Medicare claims database, we performed a national cohort study of 7229 Medicare patients more than 65 years old undergoing pancreaticoduodenectomy between 1992 and 1995. We divided the study population into approximate quartiles according to the hospital's average annual volume of pancreaticoduodenectomies in Medicare patients: very low (< 1/y), low (1-2/y), medium (2-5/y), and high (5+/y). Using multivariate logistic regression to account for potentially confounding patient characteristics, we examined the association between institutional volume and in-hospital mortality, our primary outcome measure. RESULTS: More than 50% of Medicare patients a undergoing pancreaticoduodenectomy received care at hospitals performing fewer than 2 such procedures per year. In-hospital mortality rates at these low- and very-low-volume hospitals were 3- to 4-fold higher than at high-volume hospitals (12% and 16%, respectively, vs 4%, P < .001). Within the high-volume quartile, the 10 hospitals with the nation's highest volumes had lower mortality rates than the remaining high-volume centers (2.1% vs 6.2%, P < .01). The strong association between institutional volume and mortality could not be attributed to patient case-mix differences or referral bias. CONCLUSIONS: Although volume-outcome relationships have been reported for many complex surgical procedures, hospital experience is particularly important with pancreaticoduodenectomy. Patients considering this procedure should be given the option of care at a high-volume referral center.

Variation in the use of laparoscopic cholecystectomy for elderly patients with acute cholecystitis.

HYPOTHESIS: There is regional variation in the use of laparoscopic cholecystectomy (LC) for acute cholecystitis in the New England (Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut) Medicare population. DESIGN: Population-based, cross-sectional study. SETTING: Hospital service areas (HSAs), small geographic areas reflecting local hospital markets, in New England. PATIENTS: We identified from the claims database 21 570 Medicare patients undergoing cholecystectomy between 1995 and 1997. Patients with acute calculous cholecystitis but no bile duct stones (n = 6156) were then identified using International Classification of Diseases, Ninth Revision diagnostic codes. To reduce variation by chance, we excluded patients residing in HSAs with fewer than 26 cases, leaving 5014 patients in 77 HSAs. MAIN OUTCOME MEASURES: For each HSA, we assessed the rate of cholecystectomies performed laparoscopically, mortality, and hospital length of stay. RESULTS: Overall, 53.5% of patients with acute cholecystitis underwent LC. There was wide regional variation in the rate of patients undergoing laparoscopic surgery, from 30.3% in the Salem, Mass, HSA to 75.5% in the Hyannis, Mass, HSA. Seventeen HSAs had rates below 40%, while 9 had rates above 70%. The average length of stay (7.6 days) was approximately 1 day shorter in HSAs with high rates of patients undergoing LC than in other HSAs. There was no correlation between regional use of laparoscopic surgery and 30-day mortality (3.1% overall). CONCLUSIONS: The likelihood of elderly patients with acute cholecystitis receiving LC depends strongly on where they live. Efforts to reduce regional variation should focus on disseminating techniques for safe LC in this high-risk population.

Is unplanned return to the operating room a useful quality indicator in general surgery?

HYPOTHESIS: To test our hypothesis that unplanned return to the operating room (OR) is a useful quality indicator, we examined how often and for what reasons patients go back to the OR in a broad-based general surgery practice. DESIGN AND SETTING: Prospective cohort study at a rural tertiary care center. PATIENTS: Consecutive series of 3044 patients undergoing general surgery procedures in the OR between September 1, 1998, and March 31, 2000. Information about all postoperative adverse events occurring before discharge or within 30 days (whichever was longer) was collected prospectively. Unplanned return to the OR was defined as any secondary procedure required for a complication resulting directly or indirectly from the index operation. MAIN OUTCOME MEASURES: Unplanned return to the OR, mortality, and hospital charges. RESULTS: Overall, 107 (3.5%) had an unplanned return to the OR. A relatively small number of inpatient procedures accounted for a disproportionate share of unplanned reoperations, including colon resection (18% of total reoperations), renal transplant (9%), gastric bypass (6%), and pancreatic resection (6%). As expected, hospital charges were markedly higher for patients with unplanned returns to the OR. Reoperation was also associated with higher mortality rates; statistically significant increases were noted for pancreatic resection (33% vs 3.7%; P =.04), esophagogastrectomy (100% vs 4.2%; P =.002), and laparoscopic Nissen fundoplication (50% vs 0%; P =.01). Overall, 91 reoperations (85%) were for complications occurring at the original surgical site, including those related to an anastomosis (n = 16), surgical wound (n = 21), infection (n = 16), bleeding (n = 12), and other (n = 26). CONCLUSIONS: Unplanned returns to the OR occur across a broad spectrum of general surgical procedures and carry significant implications. Because they most often reflect problems related to the procedure itself, reoperation rates may be useful for monitoring quality across hospitals and for identifying opportunities for quality improvement locally.

The effect of peripheral vascular disease on long-term mortality after coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group.

OBJECTIVE: To examine the effect of peripheral vascular disease (PVD) on long-term mortality after successful myocardial revascularization. METHODS: We performed a regional cohort study of 2871 consecutive patients discharged alive after coronary artery bypass graft surgery at five tertiary care centers in Maine, New Hampshire, and Vermont between 1987 and 1989. Data reflecting patient characteristics, heart disease severity, and comorbidity were collected prospectively; the presence of clinical and subclinical indicators of PVD was determined by medical record review; and vital status was determined using the National Death Index (mean follow-up, 4.4 years). RESULTS: Five-year mortality following coronary artery bypass graft surgery was substantially higher in the 755 patients with indicators of PVD (20%; 95% confidence interval [CI], 17% to 23%) than in the 2116 patients without PVD (8%, 95% CI, 7 to 9; P<.001). The crude hazard ratio of long-term mortality associated with PVD was 2.77 (95% CI, 2.19 to 3.50; P<.001). After adjusting for their higher comorbidity scores, more advanced cardiac disease, and age, mortality rates in patients with PVD remained twice as high as those in patients without PVD (adjusted hazard ratio, 2.01; 95% CI, 1.57 to 2.58; P<.001). Long-term mortality was increased in patients with any of the indicators of PVD. Patients with multilevel PVD had especially high late mortality rates (adjusted hazard ratio, 2.46; 95% CI, 1.64 to 3.68; P<.001). CONCLUSIONS: Even after successful myocardial revascularization, patients with PVD remain at substantially increased risk for long-term mortality. The presence of clinical or subclinical PVD is important when predicting both short- and long-term outcomes in patients considering coronary artery bypass graft surgery.

Reexploration for hemorrhage following coronary artery bypass grafting: incidence and risk factors. Northern New England Cardiovascular Disease Study Group.

OBJECTIVE: To assess mortality and risk factors associated with reexploration for hemorrhage in patients undergoing coronary artery bypass grafting (CABG). DESIGN: Regional cohort study. Patient characteristics, treatment variables, and outcome measures were collected prospectively. SETTING: All 5 centers performing cardiac surgery in Maine, New Hampshire, and Vermont. PATIENTS: A consecutive cohort of 8586 patients undergoing isolated CABG between 1992 and 1995. MAIN OUTCOME MEASURES: Postoperative hemorrhage leading to reexploration, in-hospital mortality, and length of stay. RESULTS: A total of 305 patients (3.6%) underwent reexploration for bleeding. In these patients, in-hospital mortality was nearly 3 times higher (9.5% vs 3.3% for patients not requiring reoperation, P<.001) and average length of stay from surgery to discharge was significantly longer (14.5 days vs 8.6 days, P<.001). High rates of reexploration for hemorrhage were observed in patients with prolonged (> 150 minutes) cardiopulmonary bypass (39 [11.1%] of 351) and in those requiring an intra-aortic balloon pump intraoperatively (12 [8%] of 139). In multivariate analysis, older age, smaller body surface area, prolonged cardiopulmonary bypass, and number of distal anastomoses were associated with increased bleeding risks. The use of thrombolytic therapy within 48 hours of surgery was weakly but not significantly associated with the need for reexploration. Factors not significantly associated with reexploration included patient sex, preoperative ejection fraction, surgical priority, history of liver disease, myocardial infarction, prior CABG, renal failure, and diabetes mellitus. CONCLUSIONS: Hemorrhage requiring reexploration after CABG is associated with markedly increased mortality and length of stay. Patients predicted to have increased risks of bleeding may benefit from prophylactic use of aprotinin, aminocaproic acid, or other agents shown to reduce hemorrhage.

Prosthetic valve type for patients undergoing aortic valve replacement: a decision analysis.

BACKGROUND: In two large, randomized, clinical trials long-term survival after aortic valve replacement (AVR) was similar for patients receiving tissue and mechanical aortic heart valve prostheses. Higher bleeding rates among patients with mechanical valves, who must receive permanent oral anticoagulation to prevent thromboembolism, were offset by higher reoperation rates for valve degeneration among patients with tissue valves. Because the average age of patients undergoing AVR and clinical practices have changed considerably since the randomized clinical trials were conducted, we performed a decision analysis to reassess the optimal valve type for patients undergoing AVR. METHODS: We used a Markov state-transition model to simulate the occurrence of valve-related events and life expectancy for patients undergoing AVR. Probabilities of clinical events and mortality were derived from the randomized clinical trials and large follow-up studies. RESULTS: Although the two valve types were associated with similar life expectancy in 60-year-old patients (mean age of patients in the randomized clinical trials), tissue valves were associated with greater life expectancy than mechanical valves (10.7 versus 11.1 years) in 70-year-old patients (currently mean age of AVR patients). For 70-year-old patients, the effects of major bleeding complications (24%) with mechanical valves substantially outweighed those of reoperation for valve failure (12%) with tissue valves at 12 years. Of the clinical practice changes assessed, the recommended valve type was most sensitive to changes in bleeding rates with anticoagulation. However, bleeding rates would have to be 68% lower than those reported in the European randomized clinical trial to affect the recommended valve type for 70-year-old patients. Reoperation rates would have to be five times higher, and mortality rates at reoperation would have to be four times higher to affect the recommended valve type for 70-year-old patients. CONCLUSIONS: Although mechanical valves are preferred for AVR patients less than 60 years old, most patients currently undergoing AVR are elderly and would benefit more from tissue valves.

Changes in patients undergoing coronary artery bypass grafting: 1987-1990. Northern New England Cardiovascular Disease Study Group.

A prospective study of 7,590 consecutive patients undergoing isolated coronary artery bypass grafting at five medical centers in Maine, New Hampshire, and Vermont between July 1987 and December 1990 assessed changes in patient characteristics over time. Variables included age, sex, surgical priority, ejection fraction, left ventricular end-diastolic pressure, and left main coronary artery stenosis of 90% or greater. Trends were assessed for each variable and for predicted mortality using linear regression. The mean age increased significantly, whereas ejection fraction decreased. The percentage of urgent cases increased, whereas the elective cases became less frequent. No changes were observed in the percentages of emergent cases, female patients, or patients with severe left main coronary artery disease. The predicted in-hospital mortality rose significantly from 4.2% to 5.2% (p < 0.001). The increase in urgent surgical intervention was the most substantial contributor. Subgroup analyses did not support a systematic misclassification of elective patients into the urgent group. This study demonstrates that the characteristics of the cohort of patients undergoing coronary artery bypass grafting changed substantially from 1987 to 1990. These changes should be considered when interpreting surgical outcomes.

Cost-effectiveness of preoperative autologous donation in coronary artery bypass grafting.

Concern about the safety of the allogeneic blood supply has made preoperative autologous blood donation (PAD) routine before major noncardiac operations. However, the costs and benefits of PAD in elective coronary artery bypass grafting (CABG) are not well established. We used decision analysis to (1) calculate the cost-effectiveness of PAD in CABG, expressed as cost per year of life saved, and (2) compare the health benefits of reducing allogeneic transfusions with the potential risks of autologous blood donation by patients with coronary artery disease. A prospective study of 18 institutions provided data on transfusion practice and blood product costs in CABG. On average, PAD in CABG costs $508,000 to $909,000 per quality-adjusted year of life saved, depending on the number of units donated. Preoperative autologous blood donation is more cost-effective (as low as $518,000 per year of life saved) when targeted to younger patients undergoing CABG at centers with high transfusion rates. The cost-effectiveness of PAD is strongly dependent on estimates of posttransfusion hepatitis incidence, but less so on plausible estimates of the current risk of human immunodeficiency virus transmission. Although the actual risk of PAD is uncertain, even a small fatality risk (> 1 per 101,000 donations) associated with blood donation by patients awaiting CABG negates all life expectancy benefits of PAD. At current costs, PAD by patients awaiting CABG is not cost-effective, producing small health benefits at high societal cost. For the individual patient, the risk of donating blood before CABG may well outweigh the benefits associated with fewer allogeneic transfusions.