The cost-effectiveness of myocardial revascularization

The formulation of a rational strategy for containing health care costs requires consideration of the cost-effectiveness of the various therapeutic alternatives available in order to assess the cost-effectiveness of myocardial revascularization in treating ischemic heart disease, the authors retrospectively analysed the costs of hospitalization and the long-term survival of 332 patients who underwent this procedure at the Victoria Hospital, London, Ontario, between 1974 and 1977. On the basis of angiographic findings the patients were divided into two groups: 51 patients who had advanced abnormalities in segmental wall motion of the left ventricle (group 1) and 281 patients who had relative preservation of left ventricular function (group 2). The presence of left ventricular dysfunction did not significantly increase the operative risk (operative mortality for group 1 v. group 2, 2.0% v. 1.8%), but showed a significant (P less than 0.01) effect on long-term survival (5-year actuarial survival rate +/- SEM for group 1 v. group 2, 74.7% +/- 9.5% v. 94.7% +/- 1.1%). Analysis of pertinent hospitalization data acquired from the Ontario Ministry of Health showed a highly significant (P less than 0.002) reduction in hospitalization expenses in the first postoperative year that continued throughout the 5-year follow-up period. The favourable effect of myocardial revascularization on long-term hospitalization costs, although evident in both groups of patients, was most marked in group 1 patients with compromised left ventricular function, as shown by the respective amortization times of costs for patients with left ventricular dysfunction, those with preserved function and for the two groups together: 22.3, 38.4 and 35.9 months postoperatively.

Economic assessments of medical practices and technologies

Cost-effectiveness analysis can be useful as an aid to decision makers concerned with the allocation of health care resources. The approach requires an explicit, quantitative measure of the health effectiveness of the intervention under analysis, as well as a measure of its net resource cost. Cost-effectiveness analyses are less useful if the measure of effectiveness is expressed in units that are unique to the intervention or class of interventions being considered than if the measure is comparable across interventions. The life year as a unit offers the advantage of comparability across programs, but its use in cost-effectiveness analysis can be misleading if the effects of the program in question include changes in the quality of life. Cost-effectiveness analyses of estrogen therapy in the menopause, high blood pressure control, and coronary artery bypass surgery are used to illustrate the method of analysis and the sensitivity of conclusions to the manner in which quality-of-life impacts are included explicitly (or excluded entirely). Cost-effectiveness analyses, therefore, should always include sensitivity analyses in which preference weights and parameters are varied over the plausible range. Inability to measure the quality of life and preferences regarding such effects should not be an excuse for failing to include them in a cost-effectiveness analysis.

Coronary artery graft surgery

The last decade has seen significant technical advances in equipment for the procedure of, and the surgeon's operating skill in coronary artery by pass surgery. Such surgery is indicated when, despite medical treatment, angina is disabling; although evidence is increasing that patients whose pain is controlled should be considered for surgery. Late operations are more complex and expensive, and patients are exposed to a higher risk of sudden death in the intervening period. Delay may also allow the disease to progress to an inoperable state. Patients unlikely to benefit from medical treatment should be offered surgery as soon as their disease is identified by angiography. Intensive medical treatment, with its poorer control of symptoms, leads to an increasing dependence on the State of medicine, hospital facilities and sickness benefits. The reputedly expensive coronary artery bypass operation is cheaper both to the State and to the patient tha unoperated invalidism.

Coronary artery bypass graft surgery: clinical decision making and cost-effectiveness analysis

Decision-analytic techniques were used to evaluate the choice between an aortocoronary bypass operation and medical management in a set of hypothetical patients with coronary artery disease. The decision framework incorporates variables believed to have an important bearing on the choice of treatment. Probability estimates were obtained from two cardiologists and one cardiac surgeon. Patient preferences for the trade-off between years of survival and the quality of life as reflected by the severity of angina pectoris were made explicit by assigning utility values to alternative health outcomes. The results are expressed in terms of quality-adjusted years of life expectancy. Decision analysis favored operation for 13 of the 14 hypothetical patients, including patients with one- and two-vessel disease. The one patient for whom medical treatment was preferred had mild angina pectoris, severe left ventricular dysfunction, and a poor prognosis regardless of therapeutic modality. The results are sensitive to changes in the probability of long-term survival, but not to changes in operative mortality rates. In five patients, the physicians' clinical judgments favored medical treatment, whereas their decision-analysis-derived estimates of survival favored operation. Possible explanations for these discrepancies are discussed. A simplified cost-effectiveness analysis for patients in whom surgery was the optimal treatment indicated costs ranging from $1,500 to $250,000 per year of life gained and from $1,500 to $32,000 per quality-adjusted year of life gained.

Selection of patients for coronary artery bypass operations

Bypass operations have proved to be an effective treatment for advanced coronary artery disease. Randomized clinical trials have now shown that compared with medical treatment, bypass operations enhance survival in patients who have three-vessel disease or left main coronary stenosis. The goals of both medical and surgical treatment should be to improve a patient's quality of life, extend survival and reduce medical care costs. Preliminary data suggest that bypass operations may be less costly than medical treatment in patients with severe angina that requires repeated or prolonged stays in hospital.

Employment status after coronary bypass operations and some cost considerations

The occupational consequences and expenses of the bypass operation have been investigated in 100 survivors of 102 consecutive operations for coronary artery bypass grafting. There was one late death 8 months after the operation, and four patients were lost to follow-up, providing a total of 95 patients for survey. Patients were divided into four groups: I, those working before and after the operation (43); II, those working before but not after the operation (18); III, those not working before the operation who returned to work after the operation (8); IV, those not working before or after the operation (26). The four groups were analyzed for age, type of employment, severity of disease, ventricular function, incidence of perioperative infarction, graft patency, postoperative treadmill performance, and exepnses incurred. Profiles of the four groups have emerged which may have predictive value. Group I patients tend to be under age 55, self-employed in higher skill occupations, and with significant left ventricular dysfunction. Group II patients tend to be over age 55, employed in lower skill occupations, but also without significant left ventricular function. Of the 34 patients unemployed for 6 months in 24 months before the operation, 24% (eight) returned to work after the operation. The typical total bill for diagnosis and treatment was $15,000, of which insurance paid $12,000 and the patient paid $3,000.

[Changes in work status in a French-Canadian population after aorto-coronary bypass surgery]

Work status after aortocoronary bypass surgery was evaluated in 1 320 male patients who were less than 60 years old at the time of their operation. The percentage of working patients is maximal two years after surgery (66.5 p. 100) and decreases gradually (53 p. 100) at five years. This percentage remains lower than the 84 p. 100 and 69 p. 100 which were observed twelve and six months before the operation. Multivariate analyses showed that the length of the period of pre-operative inactivity had a preponderant role in predicting work status after surgery. The second best predictor was the type of work in patients aged 45 or more and the educational level in younger patients. All other variables-duration of illness, functional class, other illness, postoperative complications, marital status, annual income, age-had a lesser role. Variables predictive of continued employment (greater than or equal to 2 ans) after surgery were similar. Univariate analyses on postoperative factors showed a negative correlation between recurrence of angina and return to work. A majority of patients who never returned to work after surgery kept a stable income (65.5 p. 100) and 83 p. 100 of them received financial aid from the government.

Return to work after coronary artery bypass operation

A societal cost-benefit argument has been made for the coronary artery bypass graft (CABG) operation. Most patients experience improvement in symptoms and many can return to a productive livelihood. To estimate the rate of return to work and identify the factors influencing that outcome, we analyzed the work status before and after operation in a follow-up of 105 patients undergoing CABG operations in a new teaching hospital. Overall, relief or improvement in angina was accomplished in 92% of patients, and there was a 10% net increase to th work force after operation. Of all variables studied, preoperative work status was found to be the most statistically significant predictor of the postoperative return to work; other factors associated with return to work included symptomatic relief or improvement, age, and educational level. Preoperative and postoperative means of support did not play a major role in determining work outcome.

Research related to surgical treatment of coronary artery disease

In the past 20 years, basic and clinical research have provided new information on coronary artery surgery. For example, several studies have shown that coronary artery bypass grafting is more effective than medical treatment in relieving the symptoms of chronic disabling angina pectoris. However, we still do not have definitive answers to many questions. What factors in the patient, in the operation and in the care after operation determine success in surgical treatment? Does the operation prolong useful life? Is the operation affordable? These questions are difficult. Further research is needed to solve complex problems relating to surgical vs medical treatment of coronary artery disease.

Unstable angina pectoris: a comparison of the costs of medical and surgical treatment

This study compares the inpatient costs of therapy of patients with unstable angina pectoris randomized to surgical or medical therapy at the University of Alabama in Birmingham as part of the National Cooperative Study Group. For 74 patients followed up for 2 years, the mean inpatient charges were $4,728 for 22 medically treated patients, $9,528 for 34 surgically treated patients and $20,215 for 18 patients who crossed over from medical to surgical therapy. Differences among the three groups were statistically significant (P less than 0.001). Stepwise multiple regression analysis of total inpatient charges with medical and procedural factors as explanatory variables showed that a history of congestive heart failure, the number of infarctions during the period of the study, the duration of the longest anginal attack, the type of unstable angina and the type of treatment were significant predictors of total inpatient cost, with an R2 value of 0.829 (P less than 0.001). These variables explain the cost of treatment. One should not infer that they will also predict the appropriate type of treatment for patients with unstable angina. Although the cost of surgical therapy was double the cost of therapy for patients treated only medically, those medically treated patients whose therapy failed and who subsequently required surgery incurred mean costs twice those of the surgically treated patients and four times of patients who received only medical therapy. Reassessment of previous criticism of the high cost of surgical therapy is indicated.