Biomedical subjects
J D Birkmeyer
Publications and source records attributed to J D Birkmeyer.
The cost-effectiveness of preoperative autologous blood donation for total hip and knee replacement.
Although the frequency of preoperative autologous blood donation is increasing dramatically, the economic implications of its use remain largely unexplored. Decision analysis was used to calculate the cost-effectiveness of autologous blood donation for hip and knee replacement. Cost-effectiveness, expressed as cost per quality-adjusted year of life saved, was based on observed red cell use in 629 patients undergoing surgery at two tertiary-care centers. Autologous blood donation for bilateral and revision joint replacement cost $40,000 per quality-adjusted year of life saved at Center 1 and $241,000 at Center 2. Autologous blood donation for primary unilateral hip replacement cost $373,000 per quality-adjusted year of life saved at Center 1 and $740,000 at Center 2. Autologous blood donation was least cost-effective for primary unilateral knee replacement ($1,147,000/quality-adjusted year of life saved at Center 1 and $1,467,000/year at Center 2). Differences between autologous blood collections and transfusion requirements explained variations among procedures in the cost-effectiveness of autologous blood donation. Higher transfusion rates in autologous blood donors than in nondonors accounted for the poorer cost-effectiveness of autologous blood donation at Center 2 than at Center 1. Autologous blood donation is not as cost-effective as most accepted medical practices. Its cost-effectiveness can be improved substantially by the avoidance of overcollection and overtransfusion of autologous blood.
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.
Should patients with Björk-Shiley valves undergo prophylactic replacement?
About 85,000 patients have undergone replacement of diseased heart valves with prosthetic Björk-Shiley convexo-concave (CC) valves. These valves are prone to fracture of the outlet strut, which leads to acute valve failure that is usually fatal. Should patients with these valves undergo prophylactic replacement to avoid fracture? The incidence of strut fracture varies between 0% and 1.5% per year, depending on valve opening angle (60 degrees or 70 degrees), diameter (less than 29 mm or greater than or equal to 29 mm), and location (aortic or mitral). Other factors include the patient's life expectancy and the expected morbidity and mortality associated with reoperation. We have used decision analysis to identify the patients most likely to benefit from prophylactic reoperation. The incidence of outlet strut fracture was estimated from the data of three large studies on CC valves, and stratified by opening angle, diameter, and location. A Markov decision analysis model was used to estimate life expectancy for patients undergoing prophylactic valve replacement and for those not undergoing reoperation. Prophylactic valve replacement does not benefit patients with CC valves that have low strut fracture risks (60 degrees aortic valves and less than 29 mm, 60 degrees mitral valves). For most patients with CC valves that have high strut fracture risks (greater than or equal to 29 mm, 70 degrees CC), prophylactic valve replacement increases life expectancy. However, elderly patients with such valves benefit from prophylactic reoperation only if the risk of operative mortality is low. Patient age and operative risk are most important in recommendations for patients with CC valves that have intermediate strut fracture risks (less than 29 mm, 70 degrees valves and greater than or equal to 29 mm, 60 degrees mitral valves). For all patients and their doctors facing the difficult decision on whether to replace CC valves, individual estimates of operative mortality risk that take account of both patient-specific and institution-specific factors are essential.
Estimates of risk of posttransfusion hepatitis.
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Variation in carotid endarterectomy mortality in the Medicare population: trial hospitals, volume, and patient characteristics.
CONTEXT: The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Atherosclerosis Study (ACAS) demonstrated the efficacy of carotid endarterectomy (CEA) in reducing the risk of stroke and death in selected patients when surgery was performed in institutions whose participation depended on demonstrated excellence. Thirty-day mortality rates in the trials were very low: 0.6% in NASCET and 0.1% in ACAS. OBJECTIVE: To assess perioperative mortality among Medicare patients undergoing CEA in all nonfederal institutional settings. DESIGN: Retrospective national cohort study. SETTING AND PATIENTS: All 113300 Medicare patients undergoing CEA during 1992 and 1993 in "trial hospitals" (those participating in NASCET and ACAS, n=86) and "nontrial hospitals" (all other nonfederal institutions performing CEAs, n=2613). Nontrial hospitals were stratified into terciles based on volume of CEAs performed. MAIN OUTCOME MEASURES: Crude and adjusted perioperative (30 day) mortality rates. RESULTS: The perioperative mortality rate was 1.4% (95% confidence interval [CI], 1.2%-1.7%) at trial hospitals; mortality in nontrial hospitals was higher: 1.7% (95% CI, 1.6%-1.8%) (high volume); 1.9% (95% CI, 1.7%-2.1 %) (average volume); 2.5% (95% CI, 2.0%-2.9%) (low volume); (P for trend, <.001). In multivariate modeling, patients undergoing their procedures at trial hospitals had a mortality risk reduction of 15% (95% CI, 0%-31%) compared with high-volume nontrial hospitals, 25% (95% CI, 7%-40%) compared with average-volume hospitals, and 43% (95% CI, 25%-56%) compared with low-volume hospitals (P for trend, <.001). CONCLUSION: Medicare patients' perioperative mortality following CEA is substantially higher than that reported in the trials, even in those institutions that participated in the randomized studies. Caution is advised in translating the efficacy of carefully controlled studies of CEA to effectiveness in everyday practice.
Is epsilon-aminocaproic acid as effective as aprotinin in reducing bleeding with cardiac surgery?: a meta-analysis.
BACKGROUND: Although aprotinin is known to be effective in reducing postoperative hemorrhage after cardiac surgery, epsilon-aminocaproic acid, an alternative antifibrinolytic, is considerably less expensive. Because the results of 3 small randomized clinical trials comparing these 2 agents directly were inconclusive, we performed a meta-analysis to compare the relative effectiveness and adverse-effect profile of these 2 agents against placebo. METHODS AND RESULTS: Data from 52 randomized clinical trials published between 1985 and 1998 involving the use of epsilon-aminocaproic acid (n=9) or aprotinin (n=46) in patients undergoing cardiac surgery were abstracted. Our primary outcomes were total blood loss, red blood cell transfusion rates and amounts, reexploration, stroke, myocardial infarction, and mortality. The meta-analysis revealed substantial reductions in total blood loss with epsilon-aminocaproic acid and low-dose aprotinin (each with a 35% reduction versus placebo, P<0.001) and high-dose aprotinin (53% reduction, P<0.001). There were identical reductions in total postoperative transfusions with epsilon-aminocaproic acid (61% reduction versus placebo, P<0. 010) and high-dose aprotinin (62% reduction, P<0.001). The proportion of patients transfused was similarly reduced with epsilon-aminocaproic acid (OR, 0.32; 95% CI, 0.15 to 0.69) and high-dose aprotinin (OR, 0.28; 0.22 to 0.37). Although both drugs reduced rates of reexploration to similar degrees, this effect was statistically significant only with high-dose aprotinin (OR, 0.39; 0. 24 to 0.61). epsilon-Aminocaproic acid and aprotinin had no effect on risks of postoperative myocardial infarction or overall mortality. CONCLUSIONS: Because the 2 antifibrinolytic agents appear to have similar efficacies, the considerably less-expensive epsilon-aminocaproic acid may be preferred over aprotinin for reducing hemorrhage with cardiac surgery.
Efficacy versus effectiveness of carotid endarterectomy.
CONTEXT: Several well-known clinical trials have demonstrated that the value of carotid endarterectomy depends on preoperative symptoms and the degree of carotid artery stenosis. The benefit of surgery also depends on how the results of these clinical trials (defining the efficacy of carotid endarterectomy) are applied to actual clinical practice (the effectiveness of the procedure), where surgical risks are greater. COUNT: The number of carotid endarterectomies needed to prevent one major stroke or death--that is, the number needed to treat (NNT). CALCULATION: Reciprocal of the difference between the 5-year cumulative incidence of major stroke or death with medical therapy and the 5-year cumulative incidence of major stroke or death with carotid endarterectomy. DATA SOURCES: Efficacy was calculated with data from the North American Symptomatic Carotid Endarterectomy Trials and the Asymptomatic Carotid Atherosclerosis Study. In calculating effectiveness, we accounted for increased surgical mortality rates reported in population-based studies. RESULTS: For symptomatic patients, the NNT predicted by the effectiveness model differed little from that estimated by the efficacy model (10 versus 9 for severe carotid stenosis and 29 versus 23 for moderate carotid stenosis). However, the NNT predicted by the effectiveness model was substantially higher than that predicted by the efficacy model for patients with asymptomatic severe stenosis (63 versus 38). CONCLUSIONS: In symptomatic patients, carotid endarterectomy is both efficacious and effective for severe and (to a lesser extent) moderate carotid stenosis. However, in asymptomatic patients, the benefits observed in published trials may overestimate those likely to be achieved in clinical practice.
Trends in the use of radical prostatectomy for treatment of prostate cancer.
CONTEXT: The incidence of prostate cancer and rates of radical prostatectomy increased sharply in the Medicare population (men older than 65 years of age) after the introduction of prostate-specific antigen screening in the late 1980s. PRACTICE PATTERN EXAMINED: Trends in age-specific rates of use of radical prostatectomy in U.S. men between 1989 and 1995. DATA SOURCE: The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program. RESULTS: Overall, rates of radical prostatectomy more than doubled between 1989 and 1992 (from 78 per 100,000 men to 206 per 100,000 men) but decreased by a third between 1992 and 1995 (to 146 per 100,000 men). The pattern in overall radical prostatectomy rates between 1992 and 1995, however, obscures changes that occurred for men in different age groups. Decreases in radical prostatectomy rates were most dramatic in elderly persons, dropping 51% in men 70 to 74 years of age and 71% in men 75 years of age or older. In contrast, rates in younger men continued to increase between 1992 and 1995, rising 42% in men 45 to 49 years of age and 18% in men 50 to 54 years of age. In each age group, trends in surgery rates mirrored trends in cancer detection rates. CONCLUSIONS: Surgical treatment of prostate cancer in older men is decreasing; however, surgery rates are increasing in younger men. These divergent trends reflect the pattern of prostate cancer detection in clinical practice.
Potential benefits of regionalizing major surgery in Medicare patients.
CONTEXT: Given the strong "volume-outcome" relations observed with many surgical procedures, concentrating surgery in high-volume hospitals could substantially reduce the number of surgical deaths. We explored the potential benefits of regionalizing 10 high-risk procedures for the 38 million Americans enrolled in Medicare. COUNT: Number of lives saved in 1 year. CALCULATION: Current number of deaths occurring with each procedure multiplied by the average mortality reductions that plausibly could be achieved with regionalization. DATA SOURCE: The current number of surgical deaths was obtained from the 1995 MEDPAR file of the Medicare claims database. Expected mortality rate reductions with regionalization, estimated from published volume-outcome studies, were tested over a wide range in sensitivity analysis. RESULTS: Of 381,000 Medicare patients undergoing any 1 of the 10 procedures in 1995, approximately 17,000 surgical deaths occurred. The total number of lives saved by regionalization depends on assumptions about the mortality reductions likely to be achieved, varying from 853 (5% reduction) to 4266 (25% reduction). Regionalizing common, intermediate-risk procedures (e.g., cardiovascular procedures) would save far more lives than regionalizing less-common, higher-risk operations (e.g., major cancer resections). CONCLUSIONS: Even with conservative assumptions about reduction in surgical mortality likely to be achieved, the benefits of regionalizing major procedures in Medicare patients could be substantial. Policymakers should focus on common procedures before less-common, high-risk operations.
Potential reduction in mortality rates using an intensivist model to manage intensive care units.
CONTEXT: Because of evidence suggesting that outcomes are better in "intensivist-model" intensive care units (ICUs), the Leapfrog Group's hospital safety standards propose that ICUs be managed by critical care physicians (intensivists) who work exclusively in the ICU. COUNT: Number of lives saved annually in the United States. CALCULATION: Lives saved = (number of ICU admissions x in-hospital mortality rate of ICU patients) x reduction in mortality rates associated with the intensivist model. DATA SOURCE: Reduction in mortality rate associated with intensivist-model ICUs was determined by performing a structured literature review from 1986 to the present using MEDLINE. Other variables were estimated from various data sources. RESULTS: In the nine studies that met our selection criteria, relative reductions in mortality rates associated with intensivist-model ICUs ranged from 15% to 60%. On the basis of the most conservative estimate of effectiveness (15% reduction), full implementation of intensivist-model ICUs would save approximately 53,850 lives each year in the United States. CAUTIONS: Given the large number of ICU patients and their high baseline risks, even modest reductions in mortality rates would save many lives. Because of potential constraints related to the workforce and other resources, the feasibility of fully implementing intensivist-model ICUs nationwide is uncertain.
Operative mortality with elective surgery in older adults.
CONTEXT: For patients considering elective major surgery, information about operative mortality risks is essential for careful decision making. Because available information is often limited to educated guesses or optimistic data from case series, we examined surgical mortality by using nationwide data. PRACTICE PATTERN EXAMINED: Operative mortality in 1.2 million patients in the Medicare system who were hospitalized between 1994 and 1999 for major elective surgery (six cardiovascular procedures and eight major cancer resections). DATA SOURCE: MEDPAR file of the National Medicare claims database for patients 65 years of age and older. OUTCOMES: Operative mortality, defined as death within 30 days of the operation or death before discharge. RESULTS: Overall operative mortality varied widely according to procedure. Procedures associated with relatively low mortality risk included carotid endarterectomy (1.3%) and nephrectomy (2.3%). Overall mortality was greater than 10% for other procedures, such as mitral valve replacement (10.5%), esophagectomy (13.6%), and pneumonectomy (13.7%). In general, mortality risk increased with age. Operative mortality for patients 80 years of age and older was more than twice that for patients 65 to 69 years of age. CONCLUSION: Population-based operative mortality for major surgery varies by procedure and patient age and is considerably higher than that typically reported in case series and trials.
Cardiologists performing peripheral angioplasties: impact on utilization.
CONTEXT: Angioplasty and stent placement for peripheral arterial occlusive disease has traditionally been performed by radiologists and surgeons. However, cardiologists have recently begun to perform these procedures. It is unknown whether this has affected how often the procedure is done. OBJECTIVE: To assess how the proportion of peripheral angioplastics performed by cardiologists in a geographic area relates to population-based angioplasty rates. DESIGN: Cross-sectional analysis of all U.S. Medicare beneficiaries undergoing peripheral arterial (i.e., renal, iliac, or lower extremity) angioplasty in 1996 using Part B (physician) claims for cardiovascular procedures. Physician specialty was obtained from the American Medical Association's masterfile and Medicare. MEASURES: For each of the 306 U.S. hospital referral regions (HRRs), we calculated the proportion of procedures performed by cardiologists and rates of peripheral arterial angioplasty (adjusted for age, sex, and race). RESULTS: More than 37,000 peripheral arterial angioplastics were performed on Medicare beneficiaries in 1996 (50% for lower extremity, 33% iliac, and 17% renal arterial disease). Cardiologists performed 26% of these procedures overall, including 37% of the renal angioplastics. Few (12%) procedures were done as part of a cardiac catheterization; instead, most were done as a separate procedure. Use of peripheral angioplasty varied more than 14-fold across HRRs (median, 12 procedures per 10,000 beneficiaries; 10th to 90th percentile, 4.1 to 57.9). The mean angioplasty rate in HRRs where cardiologists performed 50% or more of the procedures was almost double that of regions where they performed none (21.9 vs. 12.1 procedures per 10,000 beneficiaries; P < 0.001). CONCLUSIONS: Cardiologists are performing a substantial proportion of peripheral angioplasties. Rates of these procedures are highest in regions where cardiologists do most of the angioplasties.