Cost of cardiac care in the three years after coronary catheterization in a contained care system: critical determinants and implications.

OBJECTIVES: We sought to determine the clinical, angiographic, treatment and outcome correlates of the intermediate-term cost of caring for patients with suspected coronary artery disease (CAD). BACKGROUND: To adequately predict medical costs and to compare different treatment and cost reduction strategies, the determinants of cost must be understood. However, little is known about the correlates of costs of treatment of CAD in heterogeneous patient populations that typify clinical practice. METHODS: From a consecutive series of 781 patients undergoing cardiac catheterization in 1992 to 1994, we analyzed 44 variables as potential correlates of total (direct and indirect) in-hospital, 12- and 36-month cardiac costs. RESULTS: Mean (+/-SD) patient age was 65+/-10 years; 71% were men, and 45% had multiple vessel disease. The initial treatment strategy was medical therapy alone in 47% of patients, percutaneous intervention (PI) in 30% and coronary artery bypass graft surgery (CABG) in 24%. The 36-month survival and event-free (death, infarction, CABG, PI) survival rates were 89.6+/-0.2% and 68.4+/-0.4%, respectively. Median hospital and 36-month costs were $8,301 and $28,054, respectively, but the interquartile ranges for both were wide and skewed. Models for log(e) costs were superior to those for actual costs. The variances accounted for by the all-inclusive models of in-hospital, 12- and 36-month costs were 57%, 60% and 71%, respectively. Baseline cardiac variables accounted for 38% of the explained in-hospital costs, whereas in-hospital treatment and complication variables accounted for 53% of the actual costs. Noncardiac variables accounted for only 9% of the explained costs. Over time, complications (e.g., late hospital admission, PI, CABG) and drug use to prevent complications of heart transplantation became more important, but many baseline cardiac variables retained their importance. CONCLUSIONS: 1) Variables readily available from a comprehensive cardiovascular database explained 57% to 71% of cardiac costs from a hospital perspective over 3 years of care; 2) the initial revascularization strategy was a key determinant of in-hospital costs, but over 3 years, the initial treatment become somewhat less important, and late complications became more important determinants of costs.

In-hospital cost of percutaneous coronary revascularization. Critical determinants and implications.

BACKGROUND: Hospital charges associated with percutaneous transluminal coronary revascularization (PTCR) in the United States exceeded $6 billion in 1994 and are likely to be constrained in some manner in the near future. Despite this high cost to the public, little is known about the major determinants and sources of variability of PTCR. METHODS AND RESULTS: From a consecutive series of 1258 procedures with attempted PTCR at a single tertiary referral center, we analyzed 65 clinical, angiographic, physician, and outcome variables as potential correlates of total (hospital and physician) cost. Direct and indirect costs, both hospital and physician, were determined on the basis of resource utilization using "top-down" methodology and were available for 1237 procedures (1086 patients) (98.3%). Mean (+/- SD) patient age was 62 +/- 11 years, 76% were male, 3% had acute myocardial infarction, 71% had unstable angina, 58% had multivessel disease, left ventricular ejection fraction was 54 +/- 12%, 26% had use of at least one nonballoon revascularization device, and median length of stay was 4.4 days. Procedural success was obtained in 89%, and major complications (death, bypass surgery, or Q-wave myocardial infarction) occurred in 3.8%. The median cost was $9176, but it was asymmetrically distributed, and the interquartile and total ranges were wide ($7333 to $13,845 and $3422 to $193,474, respectively). Analyses of independent correlates of cost and loge(cost) were performed using multivariate linear regression in training and test populations. Modeling found 15 independent preprocedural correlates of loge(cost) (R2 = .37) and 23 overall correlates (R2 = .65), excluding length of stay per se. Additional of length of stay to the model increased the explanatory power of the model to R2 = .82. Preprocedural variables most predictive of loge(cost) included presentation with acute myocardial infarction, decision delay (> 48 hours between admission and diagnostic angiography and/or > 24 hours between angiography and intervention), weekend delay, use of intra-aortic balloon counterpulsation, intention to stent, creatinine > or = 2.0 mg%, and lesion complexity (modified American College of Cardiology/American Heart Association score) (all P < .001). In the model that included postprocedural variables as well, length of stay, noncardiac death, urgent bypass surgery, use of the Rotablator, Q-wave myocardial infarction, rise in creatinine > or = 1.0%, and blood product transfusion were all strong independent correlates of loge(cost) (P < .001). CONCLUSIONS: The range of total hospital costs associated with percutaneous intervention is extraordinarily wide. Baseline patient characteristics account for nearly half of the explained variance, but procedural complications and system delays account for much of the remainder. Quantification of the determinants of cost may promote more economically efficient care in the future.