Preoperative predictors of cost in Medicare-age patients undergoing coronary artery bypass grafting

Variability drivers of treatment costs in hospitals: A systematic review

OBJECTIVES

Studies on variability drivers of treatment costs in hospitals can provide the necessary information for policymakers and healthcare providers seeking to redesign reimbursement schemes and improve the outcomes-over-cost ratio, respectively. This systematic literature review, focusing on the hospital perspective, provides an overview of studies focusing on variability in treatment cost, an outline of their study characteristics and cost drivers, and suggestions on future research methodology.

METHODS

We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Cochrane Handbook for Systematic Reviews of Interventions. We searched PubMED/MEDLINE, Web of Science, EMBASE, Scopus, CINAHL, Science direct, OvidSP and Cochrane library. Two investigators extracted and appraised data for citation until October 2020.

RESULTS

90 eligible articles were included. Patient, treatment and disease characteristics and, to a lesser extent, outcome and institutional characteristics were identified as significant variables explaining cost variability. In one-third of the studies, the costing method was classified as unclear due to the limited explanation provided by the authors.

CONCLUSION

Various patient, treatment and disease characteristics were identified to explain hospital cost variability. The limited transparency on how hospital costs are defined is a remarkable observation for studies wherein cost variability is the main focus. Recommendations relating to variables, costs, and statistical methods to consider when designing and conducting cost variability studies were provided.

Who Will be the Costliest Patients? Using Recent Claims to Predict Expensive Surgical Episodes

INTRODUCTION

Surgery accounts for almost half of inpatient spending, much of which is concentrated in a subset of high-cost patients. To study the effects of surgeon and hospital characteristics on surgical expenditures, a way to adjust for patient characteristics is essential.

DESIGN

Using 100% Medicare claims data, we identified patients aged 66-99 undergoing elective inpatient surgery (coronary artery bypass grafting, colectomy, and total hip/knee replacement) in 2014. We calculated price-standardized Medicare payments for the surgical episode from admission through 30 days after discharge (episode payments). On the basis of predictor variables from 2013, that is, Elixhauser comorbidities, hierarchical condition categories, Medicare's Chronic Conditions Warehouse (CCW), and total spending, we constructed models to predict the costs of surgical episodes in 2014.

RESULTS

All sources of comorbidity data performed well in predicting the costliest cases (Spearman correlation 0.86-0.98). Models on the basis of hierarchical condition categories had slightly superior performance. The costliest quintile of patients as predicted by the model captured 35%-45% of the patients in each procedure's actual costliest quintile. For example, in hip replacement, 44% of the costliest quintile was predicted by the model's costliest quintile.

CONCLUSIONS

A significant proportion of surgical spending can be predicted using patient factors on the basis of readily available claims data. By adjusting for patient factors, this will facilitate future research on unwarranted variation in episode payments driven by surgeons, hospitals, or other market forces.

Morbidity and Mortality in Patients 70 Years of Age and Over Undergoing Isolated Coronary Artery Bypass Surgery

Background and aim: Due to the constantly improving results of surgical revascularization for coronary heart disease even the elderly patients are offered more frequently this type of treatment. Since older age is a harbinger of reduced vital capacity and increased morbidity the results of coronary artery bypass grafting (CABG) in elderly as well as long-term benefit deserve a careful examination. Materials and methods: 1475 isolated CABG procedures performed between 1995 and 1997 in a university hospital cardiac surgery unit, divided in group I (age below 70, n = 1324) and group II (age 70 and over, n=151). A retrospective analysis of pre-operative, peri-operative and post-operative data. Results: Significant differences (lower BMI and BSA, advanced NYHA and CCS stage, higher prevalence of diabetes, renal dysfunction and extracardial atherosclerotic lesions) were found in elderly. CABG was performed in both groups with no differences in technique of procedure (only slightly longer duration of CPB in group II). However, there was markedly higher mortality (2.3 vs. 7.3 %, p < 0.005), incidence of NearMiss+ (18.4 vs. 36.4 %, p < 0.005) and post-operative morbidity (34.6 vs. 56.3 %, p < 0.005) in the older group, which was also expressed in a longer ICU stay and postoperative hospitalization. Conclusion: Coronary revascularization can be performed in elderly with higher but still acceptable risk. Higher mortality and associated morbidity is caused by higher preoperative prevalence of known risk factors as well as generally reduced vital capacity. Surgical procedure should not be denied to elderly population because of the age alone but a careful evaluation of an individual patient is required.

Coronary artery bypass graft surgery—care globalization: The impact of national care on fatal and nonfatal outcome

OBJECTIVE

In an international, prospective, observational study, we contrasted adverse vascular outcomes among four countries and then assessed practice pattern differences that may have contributed to these outcomes.

METHODS

A total of 5065 patients undergoing coronary artery bypass graft surgery were analyzed at 70 international medical centers, and from this pool, 3180 patients from the 4 highest enrolling countries were selected. Fatal and nonfatal postoperative ischemic complications related to the heart, brain, kidney, and gastrointestinal tract were assessed by blinded investigators.

RESULTS

In-hospital mortality was 1.5% (9/619) in the United Kingdom, 2.0% (9/444) in Canada, 2.7% (34/1283) in the United States, and 3.8% (32/834) in Germany (P = .03). The rates of the composite outcome (morbidity and mortality) were 12% in the United Kingdom, 16% in Canada, 18% in the United States, and 24% in Germany (P < .001). After adjustment for difference in case-mix (using the European System for Cardiac Operative Risk Evaluation) and practice, country was not an independent predictor for mortality. However, there was an independent effect of country on composite outcome. The practices that were associated with adverse outcomes were the intraoperative use of aprotinin, intraoperative transfusion of fresh-frozen plasma or platelets, lack of use of early postoperative aspirin, and use of postoperative heparin.

CONCLUSIONS

Significant between-country differences in perioperative outcome exist and appear to be related to hematologic practices, including administration of antifibrinolytics, fresh-frozen plasma, platelets, heparin, and aspirin. Understanding the mechanisms for these observations and selection of practices associated with improved outcomes may result in significant patient benefit.

A cost analysis of nonelective coronary artery bypass graft surgery

BACKGROUND

Previous studies suggest that nonelective coronary artery bypass graft surgery (CABG) is more costly than elective CABG. The goal of this study was to examine why cost differences exist between patients undergoing nonelective and elective CABG.

METHODS

We compared the outcomes and costs of treating 1613 consecutive patients undergoing nonelective (N = 1071) and elective (N = 542) CABG at three U.S. hospitals. Participating centers each used the same cost accounting system to provide patient-level clinical and cost data. Total, direct, and overhead costs were examined as were department-level costs.

RESULTS

Compared to elective patients, nonelective patients were of similar age (66.4 years vs 67.0 years, respectively, p = NS), but were more likely to be female (32.7% vs 24.0%, p = 0.0003). Nonelective patients had longer lengths of stay (LOS) than elective patients (9.7 +/- 0.2 days vs 6.6 +/- 0.3 days, p < 0.0001). The longer LOS among nonelective patients was primarily due to a longer preoperative LOS (2.6 +/- 0.08 days vs 0.4 +/- 0.05 days). Unadjusted in-hospital costs of treatment were 38% higher among nonelective patients ($25,111 +/-$550 vs $18,445 +/-$752, p < 0.0001). After controlling for baseline demographic and clinical differences, the increase in cost among nonelective patients was reduced to 33% (cost ratio = 1.33, 95% confidence interval = 1.27 to 1.39, p < 0.0001). The difference in cost among nonelective patients was further reduced to 16% after controlling for rates of preoperative angiography and percutaneous coronary intervention (PCI), 14% after adjusting for the use of a pacemaker or a balloon pump, and 7% after adjusting for preoperative LOS.

CONCLUSIONS

Patients undergoing nonelective CABG have longer LOS and higher costs than patients undergoing elective CABG. The increased cost among nonelective patients is largely due to differences in rates of preoperative LOS, angiography, and PCI. This differential reflects increased nonsurgical costs among patients undergoing nonelective CABG rather than surgical costs.

Recovering From Cardiac Surgery: What Patients Want You To Know

• Background Care of cardiac surgery patients has changed substantially in the past decade, with an emphasis on streamlined procedures and shortened hospital stays. The few qualitative reports of patients’ perspectives of this experience focus primarily on physical complications and discomforts during the immediate postoperative period.

• Objective To examine patients’ perceptions of the quality of the nursing and medical care they received during their hospital stay after cardiac surgery.

• Methods Data were collected from a consecutive sample of 89 cardiac surgical patients who consented to participate in 2 telephone interviews at 1 week and 6 weeks after hospitalization. Patients responded to a single open-ended question: “What do you want your nurses and doctors to know to help them do a better job?” Thematic extraction analysis of patients’ responses was conducted by using commercially available statistical software. Extracted themes were applied to the structure-process-outcome framework of quality of care.

• Results Four major themes (and 12 subthemes) were identified: (1) being satisfied (having a positive experience, getting information), (2) not being cared for (feeling depersonalized, having expectations that did not match recovery experiences, not being listened to, experiencing unprofessional behavior by care providers, experiencing continued care needs after going home), (3) physical needs unmet (sleep, pain, complications, physical environment), and (4) informational needs unmet (needing more or different information).

• Conclusions Patients want nurses and doctors to provide a smooth transition to home, recognize the patients as individuals, prepare them honestly for their experiences with specific information, and manage pain and sleep.

A cost comparison of heart transplantation versus alternative operations for cardiomyopathy

BACKGROUND

Heart transplantation is an established therapy for cardiomyopathy but is limited by organ shortage and expense. As a result, alternative operations have been proposed including coronary bypass, mitral valve repair, and left ventricular reconstruction. Because it is unknown whether alternative operations are less expensive than replacing the diseased heart, we compared in-hospital costs and early outcome of these operations with elective heart transplantation.

METHODS

We compared clinical and financial data of 268 patients with ejection fraction less than 30% who underwent elective heart transplantation (n = 52, UNOS status 2 only), coronary bypass (n = 176), mitral repair (n = 15), or left ventricular reconstruction (n = 25). Data were evaluated for between-group differences, with p less than 0.05 as significant.

RESULTS

Preoperative ejection fraction, although similar for heart transplantation (21.2% +/- 1.3%), coronary bypass (25.8% +/- 0.4%), mitral repair (22.9% +/- 1.5%), and left ventricular reconstruction (24.2% +/- 2.1%), was significantly different between the former two (p < 0.001). There was no difference in operative mortality: 5.8% (3 of 52), 3.4% (7 of 176), 6.7% (1 of 15), and 4.0% (1 of 25), respectively (p = 0.8). However, total hospital cost of heart transplantation was significantly greater than all others: $75,992 +/- $5,380, $25,008 +/- $1,446, $32,375 +/- $2,379, and $26,584 +/- $4,076, respectively (p < 0.001). Organ procurement expenses alone comprised 39.7% ($30,169) of total transplant cost. Kaplan-Meier survival analysis failed to show any survival difference between the various groups (p = 0.86)

CONCLUSIONS

Compared with heart transplantation, alternative operations yield a comparable early outcome and long-term survival, and are markedly less expensive. The cost of transplantation, which is largely due to procurement expenses, is yet another reason to attempt alternative operations for cardiomyopathy whenever feasible.

Relationship of hospital size, case volume, and cost for coronary artery bypass surgery: analysis of 12,774 patients operated on in Massachusetts during fiscal years 1995 and 1996

OBJECTIVE

This study investigates the relationship between the cost of coronary artery bypass graft surgery and both hospital size and case volume.

METHODS

Retrospective administrative and cost data were obtained for all 12,774 patients who underwent isolated coronary bypass surgery at 12 Massachusetts hospitals during 1995 and 1996. Hospitals were stratified by number of operating beds into 3 groups (group I, <250 beds; group II, 250-450 beds; group III, >450 beds). Total (diagnosis-related groups 106 + 107) annual coronary bypass cases per hospital varied from 271 to 913 (mean 532). Univariate and multivariable analyses were used to study the relationship between the direct and total cost and a number of patient (age, sex, acuity class, payer) and hospital (bed capacity, annual case volume per diagnosis-related group, cardiothoracic residency) predictor variables. For each hospital, we also studied the relationship between changes in coronary bypass case volume and the corresponding changes in average cost from 1995 to 1996.

RESULTS

Scatterplots revealed a broad range of mean direct cost of coronary bypass surgery among hospitals with comparable case volumes. When annual cases were analyzed as continuous variables, there was no linear relationship of case volume with direct or total cost of coronary bypass (r = -0.05 to +0.08) for any diagnosis-related group or year. When hospital bed capacity and case volume were grouped into strata and studied by analysis of variance, there was no evidence of an inverse relationship between these variables and cost. In multivariable analysis, patient acuity class and diagnosis-related group were the most important predictors of cost. Beds and case volume met inclusion criteria for most models but added little to the "explanation" of variability R(2), often less than 1%. Finally, substantial interhospital differences were noted in the magnitude and direction (direct vs inverse) of their 1995 to 1996 change in volume versus change in cost.

CONCLUSIONS

Within the range of hospital size and case volume represented in this study, there is no evidence that either variable is related to the cost of performing coronary bypass surgery. Massachusetts hospitals appear to function on different segments of different average cost curves. It is not possible to predict the relative cost of coronary bypass grafting at a given hospital based primarily on volume.

Preoperative correlates of the cost of coronary artery bypass graft surgery: comparison of results from three hospitals

This article furthers our understanding of the cost of coronary artery bypass graft (CABG) surgery by analyzing the extent to which preoperative correlates of cost differ among hospitals. A total of 2828 patient who underwent bypass surgery at 3 hospitals (2 teaching and 1 nonteaching) were analyzed. The preoperative correlates of direct variable cost (marginal cost) were determined by ordinary least squares regression. Age, urgent/emergent surgical priority, previous CABG, and chronic obstructive pulmonary disease (COPD) were significant contributors (P < .05) to cost in all hospitals, but overall, there were many differences. The major contributor to cost was non-white race (31.3%) at teaching hospital A, previous CABG (30.5%) at teaching hospital B, and preop insertion of intra-aortic balloon pump (IABP) (35.9%) at the nonteaching hospital. The number of significant risk factors also differed. Preoperative characteristics that contribute to cost can be quite different among hospitals and therefore results from one hospital cannot be broadly generalized to others.

Perioperative predictors of ICU and hospital costs in coronary artery bypass graft surgery

STUDY OBJECTIVE

Economic forces have precipitated intense interest in cost-saving practices for patients undergoing coronary artery bypass grafting (CABG). While several preoperative variables have been implicated in higher costs, few studies have included perioperative factors. This study evaluated the predictive power of a preoperative mortality risk measurement (Parsonnet score) and of early extubation (< or = 6 h from ICU admission) in determining ICU and hospital costs.

DESIGN

Multivariate correlational design.

SETTING

University hospital in a large metropolitan area.

PATIENTS

All patients (n = 116) undergoing isolated CABG during a 6-month period were studied after the introduction of a clinical pathway.

MEASUREMENTS AND RESULTS

Clinical data were collected. Costs data were obtained retrospectively from the institutional data system and were derived from individual patient charges by application of department-specific cost-to-charge ratios. In multivariate logistic regression, Parsonnet score (per point odds ratio [OR], 1.09; confidence interval [CI], 1.03 to 1.17), in-hospital coronary angiography (OR, 3.51; CI, 1.23 to 10.01), delayed extubation (OR, 4.59; CI, 1.29 to 16.29), and presence of arrhythmia (OR, 3.50; CI, 1.15 to 10.64) were independent predictors of ICU costs. Only Parsonnet score (OR, 1.09; CI, 1.03 to 1.15) and cardiopulmonary bypass time (OR, 1.01; CI, 1.00 to 1.02) were independent predictors of hospital costs.

CONCLUSIONS

The Parsonnet score is a useful indicator of both ICU and hospital costs. Early extubation is associated with decreased ICU costs, but is not independently predictive of hospital costs.

The STS National Database: current changes and challenges for the new millennium. Committee to Establish a National Database in Cardiothoracic Surgery, The Society of Thoracic Surgeons

BACKGROUND

The Society of Thoracic Surgeons (STS) established the National Database (NDB) for Cardiac Surgery in 1989. Since then it has grown to be the largest database of its kind in medicine. The NDB has been one of the pioneers in the analysis and reporting of risk-adjusted outcomes in cardiothoracic surgery.

METHODS AND RESULTS

This report explains the numerous changes in the NDB and its structure that have occurred over the past 2 years. It highlights the benefits of these changes, both to the individual member participants and to the STS overall. Additionally, the vision changes to the NDB and reporting structure are identified. The individuals who have participated in this effort since 1989 are acknowledged, and the STS owes an enormous debt of gratitude to each of them.

CONCLUSIONS

Because of their collective efforts, the goal to establish the STS NDB as a "gold standard" worldwide for process and outcomes analysis related to cardiothoracic surgery is becoming a reality.

The Society of Thoracic Surgeons National Database: current status and future directions

The Society of Thoracic Surgeons National Database, established seven years ago by thoracic surgeons for self improvement and quality assurance, now has 1,181,464 patients registered, including 897,914 coronary artery bypass operations. Risk-adjusted 30 day mortality for coronary bypass procedures, unadjusted mortality for other cardiothoracic procedures, unadjusted morbidity and length of stay as well as several processes of care are measured. There has been a progressive decrease in operative mortality and length of stay over the past seven years. Deaths, complications, and lengths of stay are stratified according to estimated risk of death. Definitions have been refined in conjunction with the American College of Cardiology. The database is being increasingly utilized for state analyses and is in demand by other organizations and third party carriers. Logistic regression analysis is now utilized for development of the risk models. The database has been useful for health care policy decisions and can be useful for our Professional Affairs Committee in their dealings with government. Other uses include measuring access to care and cost. Data quality improvement measures have been put in place, as well as data manager education. The General Thoracic and Congenital data acquisition packages are being modified and improved, and a goal is to begin collecting longitudinal data to demonstrate the long term efficacy of thoracic procedures. The data elements have been decreased from 500 to 200+ core variables for simplification. With the changing healthcare environment and emphasis on cost cutting, collecting valid data by a national specialty group enhances the monitoring of quality of care, thus protecting our patients from overzealous cutbacks. Data is essential to document the efficacy, quality and cost-effectiveness of the procedures we perform and is a necessary tool for each of us to have to assure the quality and continued success of our practices.