Perioperative risk factors affecting hospital stay and hospital costs in ...

European Journal of Cardio-thoracic Surgery 11 (1997) 1133 – 1140

Perioperative risk factors affecting hospital stay and hospital costs in open heart surgery for patients] 65 years old1 Javier Fernandez a,b,*, Chao Chen a,b, Gail Anolik a, Otto B. Brdlik a,b, Glenn W. Laub a,b, William A. Anderson a,b, Lynn B. McGrath a,b a

Di6ision of Cardiothoracic Surgery, Department of Surgery, Deborah Heart and Lung Center, 200 Trenton Road, Browns Mills, New Jersey 08015, USA b Uni6ersity of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903, USA Received 9 October 1996; received in revised form 10 February 1997; accepted 18 February 1997

Abstract Objective: Demographic changes, associated with increased demands for open heart surgery in the elderly, place increased burden on financial resources. To evaluate perioperative risk factors affecting incidence of hospital events and estimation of hospital charges, 2577 patients] 65 years (range 65–91), operated on from January 1991 to December 1994, were compared with a concurrent cohort of 2642 younger patients. Methods: Statistical analysis, by surgical procedure, focused on hospital mortality, key postoperative complications affecting length of hospital stay and hospital charges. Results: Overall hospital mortality was 4.7%, 3.5% in younger patients versus 6.1% in the older group (P 0.01). Mortality was significantly lower in patients less than 65 years undergoing coronary artery bypass grafting (3% versus 5%, PB0.01) and valve replacement (4% versus 9%, P =0.01). Significant risk factors for hospital death in the elderly: diabetes (PB0.01), hypertension (P B0.01), myocardial infarction (PB0.01) and congestive heart failure (P B0.01). Significant postoperative events, more common in older patients, included prolonged ventilation (P0.01), congestive heart failure (P 0.01), infection (P 0.01), cerebrovascular accident (P B 0.01), and intra aortic balloon pump (PB0.01). Incremental risk factors for morbidity in the elderly were: higher New York Heart Association class, congestive heart failure, emergent operation, and female gender. Mean length of hospital stay for the B65 group was 15.3 versus \19.5 days for the ]65 group (P 0.01). Length of stay over 18 days positively correlated with increased morbidity in both age groups. For patients ]65 years of age, the average hospital charge for open heart surgery was 172% higher for patients with a length of stay greater than 18 days compared with 165% for patients less than 65 years of age. Conclusions: Higher operative mortality and longer length of stay in elderly patients, resulting in increased health care costs, was associated with more co-morbidities. These results suggest interventions designed to reduce congestive heart failure and other co-morbidities may improve patient’s recovery and reduce costs. © 1997 Elsevier Science B.V. Keywords: Risk factors; Hospital stay; Surgery

1. Introduction In recent years we have witnessed increasing numbers

* Corresponding author. Tel.: +1 609 8936611, ext. 581; fax: +1 609 8930938. 1 Presented at the Tenth Annual Meeting of the European Association for Cardio-thoracic Surgery, Prague, Czech Republic, 6–9 October 1996. 1010-7940/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved. PII S 1 0 1 0 - 7 9 4 0 9 7 ) 0 1 2 1 6 - 5

of elderly patients referred for cardiac surgery, reflecting a general increase in longevity of the population. Increased acceptance of surgical intervention in a population historically managed by non-surgical methods has contributed heavily to the financial burden of providing open heart surgery (OHS) in an aging population. Advances in technology contribute to the increased acceptance of surgical interventions in the elderly. Important contributions include modern surgical strategies yielding improved results, availability of

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Table 1 Population profile Total patientsa

B65 yearsb

]65 yearsc

n (%)d

n (%)d

Age range/mean Males

21.8–91.1/63.8 3563 (68.3)

21.8 – 64.99/55.0 1889 (71.5)

65 – 91.1/72.9 1674 (65.0)

NYHA functional class I II III IV Diabetes Hypertension Liver disorder Morbid obesity COPD CHF Angina Neuro disorder Prior MI

118 1145 3088 676 1346 2860 94 961 608 1547 3899 723 2059

(2.3) (22.1) (59.6) (13.0) (25.9) (55.0) (1.8) (18.5) (11.7) (29.8) (75.0) (13.9) (39.6)

54 558 1606 334 628 1327 51 545 262 713 1950 281 1089

(2.1) (21.2) (61.1) (12.7) (23.8) (50.4) (2.0) (20.7) (10.0) (27.1) (74.0) (10.7) (41.3)

64 587 1482 342 718 1533 43 416 346 834 1949 442 970

(2.5) (23.0) (58.1) (13.4) (28.0) (59.8) (1.7) (16.3) (13.5) (32.6) (76.0) (17.2) (37.9)

3453 128 748 446 62 382

(66.2) (2.4) (14.3) (8.6) (1.2) (7.3)

1808 80 422 130 33 169

(68.4) (3.0) (16.0) (4.9) (1.2) (6.4)

1645 48 326 316 29 213

(63.8) (1.9) (12.6) (12.3) (1.1) (8.3)

P

0.01 NS

0.01 0.01 NS 0.01 0.01 0.01 NS 0.01 0.01 B0.01

Operation CABG Valve repair Valve replace CABG+Valve Repair+Replace Other cardiac Previous cardiac Surgery

1813 (34.8)

837 (31.7)

976 (38.0)

Operation type Elective Urgent Emergency

4662 (95.4) 105 (2.2) 120 (2.5)

2378 (95.2) 46 (1.8) 75 (3.0)

2284 (95.6) 59 (2.5) 45 (1.9)

0.01 0.01

NYHA, New York Heart Association; COPD, chronic obstructive pulmonary disease; CHF, congestive heart failure; MI, myocardial infarction; CABG, coronary artery bypass grafting. a n= 5219. b n=2642. c n= 2577. d Denominator corresponds to number of patients in each age cohort.

additional devices such as implantable defibrillators, and newer cardiac valves offering improved hemodynamics and enhanced durability. Our recent experience with octogenarians [2] demonstrated acceptable early and late results. Other authors have reported similar series [3,6,13]. The purpose of this research was to investigate agerelated differences between preoperative risk factors, hospital events, length of stay (LOS) and hospital charges. It was theorized that for older patients, the management of and recuperation associated with postoperative complications would result in higher charges than for younger patients. It is proposed that better understanding the relationship between age and perioperative factors, and their impact on how resources are utilized, may lead to an improved model to reduce postoperative morbidity and subsequent cost.

2. Materials and methods The study population was comprised of 5219 consecutive patients undergoing open heart surgery at Deborah Heart and Lung Center between January 1991 and December 1994. This population was divided into two age cohorts for comparison: patients ] 65 years of age (n =2577) and patients B 65 years of age (n=2642); ranging in age from 21 to 91 years. The clinical profile, including preoperative risk factors and types of operative procedures performed, is shown in Table 1. There were proportionately more males (P 0.01). Co-morbidity in patients ] 65 years of age was more likely to include diabetes, hypertension, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), and history of neurological The majority of operations were coronary artery bypass graft

J. Fernandez et al. / European Journal of Cardio-thoracic Surgery 11 (1997) 1133–1140

(CABG) procedures for both age groups. Mean bypass and cross-clamp times were 74.3937.3 min and 38.49 21.3 min, respectively. The bypass time (min) was significantly longer in the ]65 year old (78.4 versus 70.4, P 0.01) as was the crossclamp time (min) (40.6 versus 36.3, P 0.01). The mean ejection fraction, similar in both age groups, as determined by surgical assessment of cineangiography, was 46.6 913.4%. Due to missing values, New York Heart Association (NYHA) functional status and urgency of operation do not equal the population total.

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with the type of surgery. For this series, the 18 day criteria was based on an institutional mean admission to operation interval of 4 days and a mean operation to discharge interval of 14 days. Given the large number of tests performed, the conventional criterion for statistical significance (P=0.05) needs to be adjusted by Bonferroni’s inequality, to a smaller P-value. P-values between 0.001–0.01 are presented as PB 0.01. P-values B 0.001 are presented as P 0.01 and considered strong evidence to support statistical significance.

2.1. Statistical analysis Hospital charges were retrieved from our accounting system. All other clinical information, including demographic variables, medical history, admission and discharge dates, operative data and presence of postoperative complications were retrieved from the surgical department’s database. Initial analysis revealed the distribution of most variables were highly skewed. The skewness was particularly obvious in hospital charge and length of hospital stay. This digression from the normal distribution assumed with parametric approach necessitated the use of nonparametric methods. For comparison of continuous variables, Kruskal–Wallis test was used. The association between hospital LOS and hospital charge was analyzed by Spearman’s correlation coefficient. Discrete variables having two levels were analyzed by the Fisher’s exact test. Discrete variables with more than two levels were analyzed by the x 2 method. Hospital death was analyzed using two different approaches. The first approach assessed whether the presence of risk factors affected hospital mortality. This approach compared the mortality rate for all patients with and without perioperative risk factors present. The second approach assessed the effect of age on mortality by comparing mortality rates in the younger and older groups for patients having selected risk factors. Analysis was guided by the assumption that complications affected hospital charge in two interdependent ways. First, complications necessitate costly therapeutic interventions and secondly, complications necessitate additional hospital days. Complications were compared for patients with and without selected preoperative risk factors to identify those increasing the probability of a higher hospital charge. Postoperative complications that were similarly managed and of comparable clinical relevance were grouped together for the purpose of statistical analysis. The composition of groupings are detailed in the morbidity section. The effect of complications on hospital charge was assessed by comparing mean charges incurred by patients with LOS (admission to discharge) 5 18 days with that of LOS \18 days for the two age cohorts and by recording the mean charges

3. Results The overall hospital mortality was 4.7%. Younger patients experienced 93 (3.5%) hospital deaths while in the older group there were 156 (6.1%) deaths, a highly significant difference (P 0.01). Mortality rate was higher in the elderly for most surgical procedures but differences were statistically significant only in patients undergoing isolated coronary bypass (3.1% versus 5%, PB0.01) and isolated valve replacement (4.3% versus 8.9%, P= 0.01). Cardiac causes of death accounted for 74% (n= 69) of deaths in the younger group and 53% (n=83) in the elderly. Acute cardiac failure was the most frequent cause of death for both age groups. Non-cardiac causes of death accounted for 26% (n= 24) of deaths in the younger group and 47% (n =73) in the elderly. Preoperative risk factors for hospital death were compared by univariate analysis between patients with and without these risk factors in each age group. Factors significant for hospital death in the elderly and in the young included female gender (PB 0.01), higher NYHA functional class (PB 0.01), COPD (P=0.02), and CHF (PB 0.01). Risk factors which were significant for hospital death and exclusive to the elderly group were diabetes (P= 0.03) and type of operation (PB0.01): (in descending order) CABG + valve, valve replacement, valve repair, CABG, and valve repair + replacement. Surprisingly, morbid obesity reached significance only in the young (P 0.01). Left ventricular ejection fraction was lower in non-survivors in comparison to survivors in both age groups but the difference did not reach statistical significance. Mortality was also compared for patients with select perioperative risk factors. This analysis identified patients with diabetes (PB 0.01), hypertension (P 0.01), CHF (PB 0.01) and prior myocardial infarction (PB 0.01) as having higher mortality rates in the ] 65 year old group. However, previous cardiac surgery and COPD at the time of operation did not affect hospital mortality.

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Table 2 Hospital morbidity Post-op complications

Ventricular arrhythmia Heart block (requiring permanent pacemaker) Periop myocardial infarction Cardiac arrest Postop intra aortic balloon pump Congestive heart failure (inotropes\24 h) Acute cardiac failure w/assist device Hemodynamic instability (chest closure delay) Cerebrovascular accident Neuropsychiatric General pulmonarya Prolonged ventilation (\48 h) Renal dialysisb Bleedingc Infectiond Vasculare

B65 years

]65 years

n (%)

n (%)

106 27 66 62 102 127 46 77 41 7 303 135 14 111 134 41

120 42 59 63 140 206 29 78 76 17 324 228 22 137 223 31

(4.0) (1.0) (2.5) (2.4) (3.9) (4.8) (1.7) (2.9) (1.6) (.3) (11.5) (5.1) (.5) (4.2) (5.1) (1.6)

(4.6) (1.6) (2.3) (2.4) (5.4) (8.0) (1.1) (3.0) (2.9) (.7) (12.6) (8.8) (.8) (5.3) (8.6) (1.2)

P

NS NS NS NS B0.01 0.01 NS NS 0.01 0.04 NS 0.01 NS NS 0.01 NS

a

Bronch+re-intubation, bronchopleural fistula, diaphragmatic paralysis, pneumothorax, pulmonary emboli, pleural effusion+tap, pneumonia, hemothorax, chylothorax, upper respiratory infection (treated). b Peritoneal dialysis, hemodialysis, continuous arterio-venous hemodialysis, ultrafiltration. c Coagulopathy, cardiac tamponade, bleeding, severe (requiring re-entry). d Genitourinary, leg wound, mediastinitis, native valvular, prosthetic valvular, sepsis, sterile sternal dehiscence, superficial sternal wound, intra aortic balloon pump site, other incision a infection, non-incisional (ulcer, wound). e Dissection, embolism, pseudoaneurysm, thrombosis, deep vein thrombosis, amputation, occlusion of graft or artery.

3.1. Morbidity

3.2. Length of stay and charges

The prevalence and proportion of postoperative morbidities, grouped together by clinical relevance and management, are depicted in Table 2. Significant events, more common in the older patient group, included postoperative intra aortic balloon pump (IABP) for low cardiac output (P B 0.01), CHF treated only with inotropes greater than 24 h. (P 0.01), cerebrovascular accident (P 0.01), neuropsychiatric symptoms (P =0.04), prolonged ventilation greater than 48 h (P  0.01) and infection (P  0.01). Acute cardiac failure treated with an assist device occurred in both age groups but the difference was not significant. Although univariate analysis did not identify a definite correlation between preoperative risk factors and postoperative morbidity, higher NYHA functional class and CHF showed a strong correlation with postoperative complications in the ] 65 year old. In contrast, female gender, diabetes mellitus, and urgency of operation correlated with a smaller number of postoperative events in both age groups. Postoperative infection and prolonged ventilation appeared more commonly in: females, diabetics, higher NYHA functional class III/IV, CHF, patients with previous cardiac surgery, and in emergent operations (Appendix A).

In this series, the average interval from admission to operation was 3.98 days in the B 65 year old group and 4.33 days in the ]65 year old group (P 0.01). This difference was statistically significant but not relevant economically. During this preoperative time interval, catheterization and a variety of medical tests were often performed. The overall LOS was significantly longer in the ] 65 year old: 19.5 versus 15.3 days in the younger group (P 0.01). According to operative procedure, longer LOS in the elderly was significant in isolated CABG (P 0.01), CABG+valve replacement (P 0.01), and valve repair+ replacement (P0.01). Subtracting the interval between admission and operation, the mean postoperative length of stay was 11.3 days for the younger patients and 15.2 days in the older group. Our institutional standard LOS for open heart procedures is approximately 10–14 days. Reimbursement for length of stay varies depending on the contract negotiated between the provider and the third party payer. Most patients were discharged from the hospital by the 18th day after admission leaving 461 (17.5%) of patients B 65 years and 761 (29.6%) of patients ] 65 years old remaining in the hospital past this time. Fig. 1 depicts the length of hospital stay distribution for non-survivors and in each age cohort, represented by coded bars. For non-survivors,

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The economic impact on a longer LOS for both age groups is seen in Table 3 where operative procedures are listed in ascending order of clinical, operative, and medical management resource consumption. The more complex the surgical procedure, the longer the length of hospital stay. This finding correlated with a progressive increase in hospital charges (r= 0.7; P 0.01). While the strength of this correlation is similar overall, the actual charges are higher in the ]65 year old. For both age groups, length of hospital stay greater than 18 days resulted in dramatically higher hospital charges. When LOS was 5 18 days in patients less than 65 years of age, mean hospital charge was $39,404. In contrast, the mean hospital charge was $104,462 for a hospital stay more than 18 days (P0.01) for the same age group. This difference was also observed in the older cohort when, for a LOS 5 18 days, mean hospital charge was $42,636 and $116,154 for hospital stays greater than 18 days (P 0.01). Table 4 shows a pattern of significantly higher charges overall for hospital deaths compared with hospital survivors (PB 0.01). It is noteworthy that there was a dramatic three-fold increase in overall charges for non-survivors.

Fig. 1. Hospital length of stay following open heart procedures. Red and purple bars represent percent of non-surviving patients at each interval (total deaths=250: ]65 =156, B 65 =94). Yellow and blue bars indicate percent of patients discharged alive from the hospital at the indicated intervals (total survivors entered in this calculation = 4964: ] 65= 2416, B 65= 2548). Percentages indicated at top of each bar.

most deaths occurred early or very late in hospitalization. In contrast, survivor discharge followed a smooth descent after the 19th post admission day. The longest hospital stay recorded for non-survivors was 330 days and for survivors was 219 days. Univariate analysis identified 15 of the 16 postoperative complications reviewed as significant for increasing LOS in the elderly group beyond the 18th day after admission (Appendix B). Specifically, heart block, prolonged ventilation, and CVA had the greatest impact on LOS\ 18 days. This data also demonstrated older patients without these complications had a higher percentage of hospitalization greater than 18 days than their younger counterparts. With the exception of perioperative MI, cardiac failure, and hemodynamic instability treated by an assist device, the same morbid events also significantly prolonged hospitalization in the less than 65 year old group but to a lesser degree than in the ] 65 year old. In the younger age group, cerebrovascular accident had the highest impact on LOS\ 18 days.

4. Discussion This investigation disclosed a relationship between selected perioperative risk factors and hospital death, hospital morbidity and hospital length of stay, and their financial impact as reflected in the hospital charge. Several reports have correlated preoperative risk factors with early operative mortality [5], or morbidity with hospitalization, particularly in the elderly since it appears the cost of open heart surgery for this segment of the population is significantly higher than in the young [7–12]. Our study showed that, at the time of surgery, the elderly group was in worse clinical condition when compared with the younger cohort. The elderly popula-

Table 3 Correlation between length of stay and hospital charges by age group and procedure B65 years

CABG Valve repair Valve replace CABG+valve Repair+replace

]65 Years

Mean charge $

LOS

r*

P

Mean charge $

LOS

r*

P

44,122 50,725 60,978 71,641 81,370

14.0 16.9 18.1 19.9 23.6

0.5 0.7 0.5 0.7 0.8

0.01 0.01 0.01 0.01 0.01

55,852 64,557 81,005 84,655 95,832

18.3 22.6 22.8 24.2 28.3

0.7 0.7 0.7 0.7 0.8

0.01 0.01 0.01 0.01 0.01

Overall, mean charge=$56 663, LOS= 17.4 days. LOS, length of stay; CABG, coronary artery bypass grafting. r*=Spearman’s rank correlation coefficient.

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Table 4 Comparison of mean hospital charges between hospital survivors and hospital deaths by procedure and age group B65 years

CABG Valve repair Valve replace CABG+valve Repair+replace

]65 years

Hospital deaths

Hospital survivors

P*

Hospital deaths

Hospital survivors

P*

$102 890 $246 131 $133 702 $124 709 $132 781

$42,195 $42,909 $58,145 $68,520 $76,229

0.01 0.01 0.01 NS NS

$154,045 $160,914 $156,462 $150,822 $445,606

$50,554 $55,797 $71,325 $76,234 $83,340

0.01 B0.01 0.01 0.01 NS

Overall: hospital deaths=$141 770, hospital survivors= $52 068; PB0.01. CABG: coronary artery bypass grafting. * Kruskal – Wallis.

tion had a higher incidence of co-morbid conditions, particularly CHF, diabetes, hypertension, COPD, and previous cardiac surgery, and were more likely to require emergent surgery. New York Heart Association functional class was similar in both groups. These baseline clinical characteristics clearly impacted on hospital mortality and was significantly higher in the older cohort. Overall mortality was, nevertheless, well within the ranges reported for OHS in elderly populations [1 – 3,6,7,13]. The only preoperative risk factors showing a strong correlation with postoperative morbidity were increased NYHA functional class and congestive heart failure. In general, preoperative risk factors diversely affected postoperative events, in varying degrees (as expressed by the magnitudes of individual P values), for both age groups. It appeared, from our findings, that younger as well as older patients affected by morbidity had a common denominator -a significant increase in length of hospitalization, an occurrence which has been pointed out by others [8,9,11]. This finding, in our series, was consistently associated with increased hospital charges, as has been previously described. [12] Although the mean hospital stay of 17.4 days characterized the average population, a smaller portion of patients remained hospitalized beyond this time, an aspect particularly noted in the older population. Presumably this phenomenon in the older population was related to delayed wound healing and prolonged recovery following postoperative complications when compared with the younger cohort which can ambulate and recuperate more readily. This series established a clear relationship between increased hospital LOS, charges, and complexity of operative procedures performed (r = 0.7). Length of stay was extended in complex cases such as CABG+valve replacement, or valve repair + replacement, as were the charges. Hospital charges were progressively higher with more resource consumption. This impacted most dramatically on elderly non-survivors. Based on these findings, one can surmise that imple-

mentation of measures to decrease postoperative morbidity in both age populations (with emphasis on the older group) would decrease the duration of hospitalization thereby reducing costs incurred in caring for cardiac surgery patients. Our results do not extend to answer the question ‘‘which patients should be excluded from operation due to higher risk?’’ but does emphasizes that the therapeutic approach in patients with the specific risk factors mentioned should be planned and managed with extreme care preoperatively. As Engelman et al. [4] suggests, newer strategies to hasten patient recovery in the immediate postoperative period, for the young and old, may be promising. At this institution, implementation of strategies to decrease length of stay, including ‘fast track’ protocols, same day surgery, and early extubation are underway. Furthermore, advances in linking financial and clinical databases promise to afford greater ability for building prediction models to identify the effect of specific co-morbidities on hospital events and charges. In conclusion, the operative mortality in patients ] 65 years old was significantly higher than in the younger cohort and was consistent with other published reports. Increased length of stay and hospital charges in the elderly population, strongly related to postoperative complications, could be theoretically (and practically) reduced by judicious patient selection and careful planning of operative procedures.

Acknowledgements The authors wish to thank Marcia Graybeal for the typing and meticulous revision of the manuscript, Ray Ellis for figure preparation, William Perkins for extensive literature review, Lynn Wang for database organization, Kimberly Dillon for data entry, Gabriela Lane for programming assistance, and Catherine Stemmer for assisting table preparation. Special thanks to Dr. Frank Lumia for his valuable assistance in reviewing the manuscript.

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Appendix A. Perioperative factors and postoperative morbidity*

NYHA class (III/IV) Congestive Heart failure Urgency of Operation Female Diabetes Prior open Heart surgery Hypertension Prior MI

B65 ]65 B65 ]65 B65 ]65 B65 ]65 B65 ]65 B65 ]65 B65 ]65 B65 ]65

Infection P

Prolonged ventilation P

Bleeding P

Cardiac IABP Neuro CVA P P

Renal dialysis P

NS 0.04 0.01 0.03 NS B0.01 0.01 B0.01 0.03 0.01 0.02 NS 0.03 B0.01 NS NS

NS B0.01 0.01 0.01 B0.01 B0.01 B0.01 0.01 NS B0.01 B0.01 NS B0.01 NS NS NS

NS B0.01 NS B0.01 B0.01 B0.01 NS NS NS NS B0.01 0.01 NS NS NS B0.01

NS B0.01 NS 0.01 NS NS B0.01 NS NS NS B0.01 NS B0.01 NS NS NS

NS B0.01 0.03 NS NS NS NS NS NS 0.01 0.02 NS NS NS NS NS

NS B0.01 0.02 0.02 NS NS 0.01 NS NS NS NS NS NS NS NS NS

NYHA, New York Heart Association; MI, myocardial infarction. NS, P]0.05. * For explanation of morbidity, see Section 2.

Appendix B. Effect of morbidity on hospital LOS\ 18 days B65 years Complication absent % Ventricular arrhythmia 16.6 Heart block 16.6 Perioperative myocardial16.8 infarction Cardiac arrest 16.7 Postop IABP 16.5 Congestive heart failurea 15.7 Acute cardiac failureb 17.1 Hemodynamic instability16.8 Cerebrovascular acci16.3 dent Neuropsychiatric 16.9 Pulmonary, general 15.3 Prolonged ventilation 14.8 Renal dialysis 16.9 Bleeding 16.3 Infection 14.9 Vascular 16.5 a b

Inotropes greater than 24 h. With assist device.

]65 years Complication present %

P value

Complication absent %

Complication present %

P value

26.4 55.6 25.8

0.01 0.01 NS

27.9 28.2 28.6

50.0 76.2 45.8

0.01 0.01 B0.01

29.0 30.4 44.1 15.2 24.7 63.4

0.02 0.01 0.01 NS NS 0.01

28.7 27.9 26.8 29.2 28.5 27.6

39.7 47.9 53.4 10.3 42.3 72.4

NS 0.01 0.01 0.02 0.01 0.01

57.1 30.7 58.5 50.0 33.3 57.5 51.2

0.02 0.01 0.01 B0.01 0.01 0.01 0.01

28.7 26.2 24.7 28.7 27.5 25.3 28.5

58.8 48.2 72.8 54.6 54.0 67.7 67.7

0.01 0.01 0.01 0.02 0.01 0.01 0.01

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References [1] Antunes MJ. Valve replacement in the elderly: Is the mechanical valve a good alternative? J Thorac Cardiovasc Surg 1989;98:485 – 491. [2] Cane ME, Chen C, Bailey BM, Fernandez J, Laub GW, Anderson WA, McGrath LB. CABG in Octogenarians: early and late events and actuarial survival in comparison with a matched population. Ann Thorac Surg 1995;60:1033–1037. [3] Deviri E, Merin G, Medalion B, Borman JB. Open heart surgery in Octogenarians: A review. Am J Geriatric Cardiol 1995;4:8, 14 – 16, 41. [4] Engleman RM. Mechanisms to reduce hospital stays. Ann Thorac Surg 1996;61:S26–29. [5] Holmes L, Loughead K, Treasure T, Gallivan S. Which patients will not benefit from further intensive care after cardiac surgery? Lancet 1994;344:1200–1202. [6] Horvath KA, DiSesa VJ, Peigh PS, Couper GS, Collins JJ, Cohn LH. Favorable results of coronary artery bypass grafting in patients older than 75 years. J Thorac Cardiovasc Surg 1990;99:92 – 96. [7] Katz NM, Ahmed SW, Clark BK, Wallace RB. Predictors of length of hospitalization after cardiac surgery. Ann Thorac Surg 1988;45:656 – 660. [8] Katz NM, Hannan RL, Hopkins RA, Wallace RB. Cardiac operations in patients aged 70 years and over: mortality, length of stay and hospital charge. Ann Thorac Surg 1995;60:96 – 101. [9] Lahey SJ, Borlase BC, Lavin PT, Levitsky S. Preoperative risk factors that predict hospital length of stay in coronary artery bypass patients \ 60 years old. Circulation 1992;86(suppl II):II181 – 185. [10] Mark DB. Implications of cost in treatment selection for patients with coronary heart disease. Ann Thorac Surg 1996;61:S12 – 15. [11] Peigh PS, Swartz MT, Vaca KJ, Lohmann DP, Naumheim KS. Effect of advancing age on cost and outcome of coronary artery bypass grafting. Ann Thorac Surg 1994;58:1362–1367. [12] Taylor GJ, Mikell FL, Moses W, Dove JT, Katholi RE, Malik SA, Markwell SJ, Korsmeyer C, Schneider JA, Wellons HA. Determinants of hospital charges for coronary artery bypass surgery: The economic consequences of postoperative complications. Am J Cardiol 1990;65:309–313. [13] Tsai T-P, Nessim S, Kass RM, Chaux A, Gray RJ, Khan SS,

Blanche C, Utley C, Matloff JM. Morbidity and mortality after coronary artery bypass in Octogenarians. Ann Thorac Surg 1991;51:983 – 986.

Appendix C. Conference discussion Dr W. Mohl (Vienna, Austria) : Do you think, that the age is the ultimate cause of this length of stay or did you do a stepwise logistic regression, finding out whether co-morbidity would be the most import ant factor in older patients because they are more ill, more sick than the others? Dr J. Fernandez: We did not do the regression equation. We did univariate and multivariate analysis, and the strongest correlation was the morbidity with the length of stay. The more morbidity, the greater the number of postoperative complications and correlated increase in length of stay. After 18 days post admission, defined as length of stay, the cost skyrocketed. Practically, the longer the patient stayed the more the cost. Dr S. Schueler (Dresden, Germany) : Do these data affect your reimbursement system? The reason I am asking is, that in Germany, we have kind of a fixed rate system where we get reimbursed by fixed rates for each individual procedure regardless of the risk factors of the patient. So could you tell me if there is a different negotiation practice to the health insurance companies in your country? Dr J. Fernandez: Definitely. Patients over 65 years old are reimbursed by the government, and you can see that half of the patients are over 65 years of age. Those that are under 65 years of age are reimbursed by the insurance companies. These companies are putting pressure on the institutions to decrease costs. There is a widespread sense at the present time in the US to achieve cost containment. The restrictions are coming from the third party payers, particularly the insurance companies but also the government. Does that answer your question? Dr S. Schueler: But how can you get along with a reimbursement for these patients? Dr J. Fernandez: In our institution, as opposed to other institutions in the United States, traditionally it is subsidized by contributions; 20% of the cost is carried out by donations. In a way it is a charity hospital that does not bill the patients. But in general I would say that many of the institutions do have a big problem in this respect.

.

.