Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia

BACKGROUND

The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial. Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate.

OBJECTIVE

To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S. aureus bacteremia.

DESIGN

Cost-effectiveness analysis.

DATA SOURCES

MEDLINE search of literature; clinical data from patients with S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees.

TARGET POPULATION

Patients with catheter-associated S. aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices.

TIME HORIZON

Patient lifetime.

PERSPECTIVE

Societal.

INTERVENTIONS

Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy.

OUTCOME MEASURES

Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

Compared with empirical short-course therapy, the TEE strategy cost $4938 per quality-adjusted life-year (QALY) gained. The effectiveness of the TEE strategy and the effectiveness of the long-course strategy were sufficiently similar that the additional cost of empirical long-course therapy ($1,667,971 per QALY) was higher than that which society usually considers cost-effective.

RESULTS OF SENSITIVITY ANALYSES

In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155,624 per QALY.

CONCLUSION

Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated S. aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy.

The challenge of health care delivery to the elderly patient with cardiovascular disease. Demographic, epidemiologic, fiscal, and health policy implications

Old age as our society is experiencing it is a new phenomenon. Never before in history have societies of developed countries enjoyed such longevity of life. In the next several decades the United States will face an unparalleled increase in the absolute number of elderly persons in our population. How will health care professionals, policy-makers, and society in general face the mammoth task of providing quality cardiovascular care for the elderly in an environment of limited financial resources? This article discusses the demographic, fiscal, and health policy implications of our aging society with particular emphasis on existing and anticipated impediments to the delivery of cardiovascular care to this rapidly expanding segment of our population.

The effects of New York's bypass surgery provider profiling on access to care and patient outcomes in the elderly

OBJECTIVE

The aim of this study was to examine the effects of provider profiling on bypass surgery access and outcomes in elderly patients in New York.

BACKGROUND

Since 1989, New York (NY) has compiled provider-specific bypass surgery mortality reports. While some have proposed that "provider profiling" has led to lower surgical mortality rates, critics have suggested that such programs lower in-state procedural access (increasing out-of-state transfers) without improving patient outcomes.

METHODS

Using national Medicare data, we examined trends in the percentages of NY residents aged 65 years or older receiving out-of-state bypass surgery between 1987 and 1992 (before and after program initiation). We also examined in-state procedure use among elderly myocardial infarction patients during this period. Finally, we compared trends in surgical outcomes in NY Medicare patients with those for the rest of the nation.

RESULTS

Between 1987 and 1992, the percentage of NY residents receiving bypass out-of-state actually declined (from 12.5% to 11.3%, p < 0.01 for trend). An elderly patient's likelihood for bypass following myocardial infarction in NY increased significantly since the program's initiation. Between 1987 and 1992, unadjusted 30-day mortality rates following bypass declined by 33% in NY Medicare patients compared with a 19% decline nationwide (p < 0.001). As a result of this improvement, NY had the lowest risk-adjusted bypass mortality rate of any state in 1992.

CONCLUSIONS

We found no evidence that NY's provider profiling limited procedure access in NY's elderly or increased out-of-state transfers. Despite an increasing preoperative risk profile, procedural outcomes in NY improved significantly faster than the national average.

Treatment of hyperlipidemia by specialists versus generalists as secondary prevention of coronary artery disease

Patients with known coronary disease and low-density lipoprotein >130 mg/dl who are followed by cardiologists after myocardial infarction are more than twice as likely to receive a cholesterol-lowering agent than patients followed by general internists.

Impact of early discharge after coronary artery bypass graft surgery on rates of hospital readmission and death. The Ischemic Heart Disease (IHD) Patient Outcomes Research Team (PORT) Investigators

OBJECTIVES

This study examined the impact of early hospital discharge on short-term clinical outcomes of elderly patients treated with coronary artery bypass graft surgery (CABG) in the United States in 1992.

BACKGROUND

Protocols that encourage earlier discharge of patients who have had CABG have been implemented across the country. Although delivery of efficient care benefits both patients and providers, premature discharge can adversely affect clinical outcomes, resulting in increased hospital readmissions and higher long-term costs.

METHODS

We examined the prevalence of early discharge (postoperative length of stay < or = 5 days) among 83,347 non-health maintenance organization (HMO) Medicare patients who underwent CABG in the United States in 1992. Using logistic regression models, we identified patient characteristics associated with early discharge and obtained risk-adjusted rates of death and readmission or death for postoperative lengths of stay between 4 and 14 days.

RESULTS

In 1992, 6% of Medicare patients undergoing CABG were discharged within 5 days of the operation. The prevalence of early discharge varied considerably among states, ranging from 1% to 21%. Patients discharged early tended to be younger and male and have fewer comorbid illnesses. Risk-adjusted rates of death and death or cardiovascular readmission were lowest among patients discharged early.

CONCLUSIONS

As of 1992, early discharge of elderly patients treated with CABG in non-HMO settings was not associated with higher 60-day rates of death or readmission. This suggests that physicians were able to identify low risk candidates for early discharge. Variation across the nation in early discharge rates, along with the percentage of patients without major risk factors for adverse outcomes, suggests that higher rates of early discharge might be safely achieved.

Relationship between physician and hospital coronary angioplasty volume and outcome in elderly patients

BACKGROUND

With the expectation that physicians who perform larger numbers of coronary angioplasty procedures will have better outcomes, the American College of Cardiology/ American Heart Association guidelines recommend minimum physician volumes of 75 procedures per year. However, there is little empirical data to support this recommendation.

METHODS AND RESULTS

We examined in-hospital bypass surgery and death after angioplasty according to 1992 physician and hospital Medicare procedure volume. In 1992, 6115 physicians performed angioplasty on 97,478 Medicare patients at 984 hospitals. The median numbers of procedures performed per physician and per hospital were 13 (interquartile range, 5 to 25) and 98 (interquartile range, 40 to 181), respectively. With the assumption that Medicare patients composed one half to one third of all patients undergoing angioplasty, these median values are consistent with an overall physician volume of 26 to 39 cases per year and an overall hospital volume of 196 to 294 cases per year. After adjusting for age, sex, race, acute myocardial infarction, and comorbidity, low-volume physicians were associated with higher rates of bypass surgery (P < .001) and low-volume hospitals were associated with higher rates of bypass surgery and death (P < .001). Improving outcomes were seen up to threshold values of 75 Medicare cases per physician and 200 Medicare cases per hospital.

CONCLUSIONS

More than 50% of physicians and 25% of hospitals performing coronary angioplasty in 1992 were unlikely to have met the minimum volume guidelines first published in 1988, and these patients had worse outcomes. While more recent data are required to determine whether the same relationships persist after the introduction of newer technologies, this study suggests that adherence to minimum volume standards by physicians and hospitals will lead to better outcomes for elderly patients undergoing coronary angioplasty.

Geographic variation in resource use for coronary artery bypass surgery. IHD Port Investigators

OBJECTIVES

The purpose of this study was to examine the national variability in patient-level cost and length of stay for coronary artery bypass grafting (CABG) in Medicare patients.

METHODS

Retrospective multivariate regression analysis was done using Medicare administrative files and American Hospital Association files. Patients in the study had an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure code for CABG, with accompanying 1990 procedure data, in the Medicare Provider Analysis and Review File (n = 92,449).

RESULTS

Outcome measures used were inpatient cost (exclusive of professional fees) and inpatient length of stay associated with bypass admission. The national average cost of bypass surgery was $22,847 (median $18,783), with an accompanying average length of stay of 16 days (median 13 days). Multivariate regression analysis revealed that patient-level cost and length of stay were related to clinical, demographic, hospital, and regional characteristics (R2 = 25% and 16%, respectively). After accounting for these characteristics at the patient level, considerable variation among states persisted in both cost and length of stay. In addition, states with similar adjusted lengths of stay varied widely with respect to adjusted cost. No relation was found at the state level between level of resource use and either procedural mortality or 60-day mortality/readmission rates.

CONCLUSIONS

Considerable variability exists among states in patient-level cost and length of stay for CABG surgery, after adjusting to the extent possible for clinical, demographic, hospital, and regional characteristics. The lack of association at the state level between resource use and rates of mortality and hospital readmission suggests that costs could be reduced in many areas of the United States without compromising quality of care.

Using Medicare claims data to assess provider quality for CABG surgery: does it work well enough?

OBJECTIVES

To assess the relative abilities of clinical and administrative data to predict mortality and to assess hospital quality of care for CABG surgery patients.

DATA SOURCES/STUDY SETTING

1991-1992 data from New York's Cardiac Surgery Reporting System (clinical data) and HCFA's MEDPAR (administrative data). STUDY DESIGN/SETTING/SAMPLE: This is an observational study that identifies significant risk factors for in-hospital mortality and that risk-adjusts hospital mortality rates using these variables. Setting was all 31 hospitals in New York State in which CABG surgery was performed in 1991-1992. A total of 13,577 patients undergoing isolated CABG surgery who could be matched in the two databases made up the sample.

MAIN OUTCOME MEASURES

Hospital risk-adjusted mortality rates, identification of "outlier" hospitals, and discrimination and calibration of statistical models were the main outcome measures.

PRINCIPAL FINDINGS

Part of the discriminatory power of administrative statistical models resulted from the miscoding of postoperative complications as comorbidities. Removal of these complications led to deterioration in the model's C index (from C = .78 to C = .71 and C = .73). Also, provider performance assessments changed considerably when complications of care were distinguished from comorbidities. The addition of a couple of clinical data elements considerably improved the fit of administrative models. Further, a clinical model based on Medicare CABG patients yielded only three outliers, whereas eight were identified using a clinical model for all CABG patients.

CONCLUSIONS

If administrative databases are used in outcomes research, (1) efforts to distinguish complications of care from comorbidities should be undertaken, (2) much more accurate assessments may be obtained by appending a limited number of clinical data elements to administrative data before assessing outcomes, and (3) Medicare data may be misleading because they do not reflect outcomes for all patients.

Assessing the value of newer pharmacologic agents in non-ST elevation patients: a decision support system application

Newer pharmacologic agents have demonstrated significant clinical and economic benefit in high-risk percutaneous transluminal coronary angioplasty (PTCA) patients. However, the higher costs of these agents may prohibit their use in lower-risk coronary artery disease (CAD) populations. We developed a decision support system (DSS) to determine the level of clinical effectiveness these newer agents must exhibit to be either cost-neutral or cost-effective in non-ST elevation patients. Our DSS evaluated six month cumulative costs, increased years of life saved (YOLS), and lifetime cost-effectiveness. We found that these therapies can cost as much as $1500 and be cost-neutral at six months if they reduce the composite endpoint of death, myocardial infarction (MI), or revascularization by 15%, and they may cost as much as $3000 and be cost-effective if they reduce this endpoint by 10%.

Outcome of acute myocardial infarction according to the specialty of the admitting physician

BACKGROUND

In order to limit costs, health care organizations in the United States are shifting medical care from specialists to primary care physicians. Although primary care physicians provide less resource-intensive care, there is little information concerning the effects of this strategy on outcomes.

METHODS

We examined mortality according to the specialty of the admitting physician among 8241 Medicare patients who were hospitalized for acute myocardial infarction in four states during a seven-month period in 1992. Proportional-hazards regression models were used to examine survival up to one year after the myocardial infarction. To determine the generalizability of our findings, we also examined insurance claims and survival data for all 220,535 patients for whom there were Medicare claims for hospital care for acute myocardial infarction in 1992.

RESULTS

After adjustment for characteristics of the patients and hospitals, patients who were admitted to the hospital by a cardiologist were 12 percent less likely to die within one year than those admitted by a primary care physician (P<0.001). Cardiologists also had the highest rate of use of cardiac procedures and medications, including medications (such as thrombolytic agents and beta-blockers) that are associated with improved survival.

CONCLUSIONS

Health care strategies that shift the care of elderly patients with myocardial infarction from cardiologists to primary care physicians lower rates of use of resources (and potentially lower costs), but they may also cause decreased survival. Additional information is needed to elucidate how primary care physicians and specialists should interact in the care of severely ill patients.

Economic assessment of platelet glycoprotein IIb/IIIa inhibition for prevention of ischemic complications of high-risk coronary angioplasty. EPIC Investigators

BACKGROUND

In the EPIC trial, c7E3 Fab, an antiplatelet IIb/ IIIa receptor antibody, reduced 30-day ischemic end points after high-risk coronary angioplasty by 35% and 6-month ischemic events by 23% but increased in-hospital bleeding episodes.

METHODS AND RESULTS

Of the 2099 patients randomized in EPIC, data were collected on 2038 (97%) for prospective hospital cost and major resources. Physician fees were estimated from the Medicare Fee Schedule. Regression analysis was used to examine the economic tradeoff between reduced ischemic events and increased major bleeding during the initial hospitalization. A potential cost savings of $622 per patient during the initial hospitalization from reduced acute ischemic events with c7E3 Fab was offset by an equivalent rise ($521) in costs as the result of an increase in bleeding episodes. Baseline medical costs for the bolus and infusion c7E3 Fab arm averaged $13,577 (exclusive of drug cost) compared with $13,434 for placebo (P = .42). During the 6-month follow-up, c7E3 Fab decreased repeat hospitalization rates by 23% (P = .004) and repeat revascularization by 22% (P = .04), producing a mean $1270 savings per patient (exclusive of drug cost) (P = .018). With a cost of $1407 for the bolus and infusion c7E3 Fab regimen, the cumulative net 6-month cost to switch from standard care to routine c7E3 Fab averaged $293 per patient.

CONCLUSIONS

In high-risk coronary angioplasty, aggressive platelet inhibition with c7E3 Fab, by significantly reducing ischemic events and repeat revascularization, recoups most of the cost of therapy and has the potential to pay for itself.

Impact of an interactive video on decision making of patients with ischemic heart disease

An experimental pilot study using repeated measures to examine the impact of an interactive video program on the decision making of patients with ischemic heart disease was carried on at a tertiary care center and a Veterans Affairs hospital. The patients (n = 80, mean age 61.1 years, 77% male, 75% white, 26.7% with acute myocardial infarction), who had undergone diagnostic cardiac catheterization and were found to have significant coronary artery disease (> or = 75% stenosis in at least one vessel), watched the Shared Decision-Making Program (SDP) for Ischemic Heart Disease (IHD), a novel interactive video system designed to provide information necessary for patients to participate actively in decision making. This program compares medical therapy, angioplasty, and bypass surgery through a physician narrator, patient testimonials, and empirically-based, patient-specific outcome estimates of short-time complications and long-term survival. Before and after viewing the SDP, patients completed surveys containing multiple choice questions and Likert scales. They rated the program as more helpful than all other decision aids except the physician, and after viewing the SDP they expressed increased confidence in their treatment choice and decreased confidence in alternative options (p = .0001). The greatest effects appeared to be concentrated in those patients with less education (p = .04), and the program appeared to increase anxiety in nonwhite patients compared with white patients (p = 0.07).

Outcomes of coronary artery bypass graft surgery in 24,461 patients aged 80 years or older

BACKGROUND

Coronary artery bypass graft surgery is increasingly common in patients of age > or = 80 years. Single-institution reviews have cited a wide range of mortality results after bypass surgery in this age group, in part because of limited sample sizes. Using claims data, we examined recent national trends in the use and outcomes of bypass surgery in the very elderly.

METHODS AND RESULTS

From an examination of Medicare data from 1987 through 1990, we identified 24,461 patients of age > or = 80 years who underwent bypass surgery. We compared surgical outcomes in these patients with those in Medicare patients of age 65 to 70 years. We found that the national use of bypass surgery in patients of age > or = 80 years increased 67% between 1987 and 1990. Compared with patients of age 65 to 70 years, the very elderly had significantly longer postoperative hospital stays (mean, 14.3 versus 10.4 days), higher charges (mean, $48,200 versus $38,000), and greater costs (mean, $27,200 versus $21,700). In-hospital (11.5% versus 4.4%), 1-year (19.3% versus 7.9%), and 3-year mortality rates (28.8% versus 13.1%) after bypass surgery were also significantly higher in patients of age > or = 80 years compared with younger patients. Although their initial surgical risk was high, octogenarians who underwent bypass surgery had a long-term survival rate similar to that of the general US octogenarian population.

CONCLUSIONS

The use of bypass surgery in patients of age > or = 80 years in increasing. These very elderly patients face high surgical risks and accumulate significant hospital expenses. Further research is indicated to determine whether the long-term benefits from bypass surgery in the very elderly outweigh the increased procedural risks.

Changes in mortality after myocardial revascularization in the elderly. The national Medicare experience

OBJECTIVE

To examine secular changes in the use and outcome of percutaneous transluminal coronary angioplasty and cardiac bypass graft surgery in the elderly.

DESIGN

A retrospective cohort study based on a longitudinal database created from the administrative files of Medicare.

SETTING

U.S. hospitals that perform myocardial revascularization procedures covered by Medicare.

PATIENTS

225,915 consecutive patients who had angioplasty and 357,885 consecutive patients who had bypass surgery from 1987 to 1990.

MEASUREMENTS

The rates of angioplasty and bypass surgery use; unadjusted 30-day and 1-year mortality rates after revascularization; and adjusted odds ratios for mortality by year of procedure for 1987 to 1990.

RESULTS

From 1987 to 1990, the rates of angioplasty and bypass surgery done in the elderly increased by 55% and 18%, respectively. During this period, 30-day unadjusted mortality rates after angioplasty and bypass surgery decreased by 25% (95% CI, 22% to 28%) and 12% (CI, 10% to 14%), and 1-year mortality rates decreased by 10% (CI, 8% to 11%) and 8% (CI, 7% to 10%), respectively. After adjustment for changes in patient characteristics, 30-day mortality rates after these procedures decreased by 37% (CI, 32% to 41%) and 18% (CI, 14% to 21%), and 1-year mortality rates decreased by 22% (CI, 18% to 25%) and 19% (CI, 16% to 21%), respectively.

CONCLUSIONS

The use of cardiac revascularization procedures in the elderly has steadily increased. Patients who had revascularization are progressively older, have more coded comorbid conditions, and present with more acute diseases. Although elderly patients have apparently higher risk profiles, mortality rates after angioplasty and bypass surgery in the elderly have decreased, suggesting a national improvement in the outcomes of these interventions. Health policy decisions concerning revascularization procedures in the elderly must consider these trends in improved outcome.

The relation between the volume of coronary angioplasty procedures at hospitals treating Medicare beneficiaries and short-term mortality

BACKGROUND

Previous studies have found that hospitals at which more procedures, such as coronary-artery bypass grafting (CABG) and other vascular surgery, are performed have lower rates of mortality related to these procedures than hospitals where fewer such procedures are performed.

METHODS

We examined the relation between the number of percutaneous transluminal coronary angioplasty (PTCA) procedures performed at hospitals (volume) and short-term mortality in a population of 217,836 Medicare beneficiaries 65 years of age or older who underwent angioplasty in the United States from 1987 through 1990.

RESULTS

The unadjusted in-hospital mortality among patients who underwent PTCA increased from 2.5 percent among the 10 percent of patients treated in hospitals with the highest volume of such procedures to 3.9 percent among the 10 percent of patients treated in hospitals with the lowest volume. The rate of bypass surgery after PTCA also increased, from 2.8 percent among patients in the highest-volume hospitals to 5.3 percent among those in the lowest-volume hospitals. Higher rates of mortality and CABG persisted in all the groups of patients treated in hospitals that performed fewer than 100 angioplasty procedures per year in Medicare beneficiaries; this volume in Medicare beneficiaries can be extrapolated to an overall annual volume of 200 to 400 angioplasty procedures. In a logistic-regression model, the volume of PTCA procedures at a hospital was found to be a highly significant predictor of in-hospital mortality (P < 0.001). These results suggest that if the hospitals with the lowest volume had achieved the experience and technical results of the highest-volume hospitals, 381 fewer patients would have undergone CABG and there would have been 300 fewer in-hospital deaths in the population we studied.

CONCLUSIONS

Hospitals that perform more PTCA procedures have lower short-term mortality rates after the procedure. These data provide evidence in support of the regionalization of angioplasty services.