Psychosomatics 42:68-73, February 2001
© 2001 The Academy of Psychosomatic Medicine
The Cost of Delirium in the Surgical Patient
Kathleen Franco, M.D.,
David Litaker, M.D., M.Sc.,
Joseph Locala, M.D., and
David Bronson, M.D.
Received January 21, 2000; revised May 5, 2000; accepted July 31, 2000. From the Departments of Psychiatry and General Internal Medicine, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44195. Address correspondence and reprint requests to Dr. Franco, Department of Psychiatry&Psychology, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Desk P57, Cleveland, OH 44195.
|
ABSTRACT
|
The authors identified the added cost attributable to postoperative delirium in patients undergoing elective surgery. The authors evaluated patients (n=500) before their elective surgery, assessing cognitive functioning, medical conditions, medication usage, and other information regarding their health status. Using DSM-IV criteria, the authors assessed patients for delirium on Postoperative Days 1–4. Medical record review provided laboratory, radiological, and pharmaceutical information. The authors analyzed length of stay (LOS), comprehensive cost data collected through the hospital, and a group practice financial database to determine differences among those developing delirium. Of the 500 patients assessed, 57 (11.4%) developed delirium during the study. Delirium is an extremely costly disorder, both to the patient in terms of morbidity and mortality and to the medical facility. A prolonged LOS increases charges to third party payors and reduces return to physicians and hospitals when delirium develops. Careful presurgical screening and targeted postoperative interventions may help contain LOS and costs while affording greater physical, emotional, and cognitive health to patients hospitalized for elective surgery.
Key Words: delirium • costs • surgical patient
|
INTRODUCTION
|
Nearly 20% of general hospital patients suffer from delirium1 during their admission, and even greater percentages occur for some orthopedic procedures, such as bilateral knee surgery (41%) and hip fracture repair (50%).2,3 Recognition of this condition, however, may be missed by medical providers in up to 50% of cases.2,4 Delirium is often associated with multiple complications and serious consequences, such as increased falls, fractures, disruptive behavior, and incontinence leading to bladder catheterization and an increased risk for infections.3–5 Although our understanding of the clinical dimension of this problem has improved, little is known about the financial impact of delirium on hospital costs. In an era when trimming financial waste is essential, understanding the relative impact of selected complications, such as postoperative delirium, on hospital resource utilization is helpful in deciding when screening and proven clinical interventions are warranted.
Most reports to date have focused on the effects on length of stay (LOS) and posthospital events for medical patients who develop delirium.6–8 Others, for instance, have observed that LOS is significantly longer, and the mortality rate and likelihood of being discharged to a nursing home are higher for those experiencing delirium.4,7–11 In addition to longer LOSs, Levkoff et al.12 also report a significantly higher mean of additional hospital charges for patients who develop delirium. When medically ill patients develop delirium and other psychiatric disturbances in general hospitals, higher health care costs result.13
Current efforts at containing the costs of the care for hospitalized patients with delirium have been limited by significant variation in the use of diagnostic criteria and therapeutic interventions. Single psychiatric consultation visits, for example, do not necessarily result in reduced costs.14 Interventions by nurses to reduce companion utilization15 and psychiatric teams to reduce LOS16 have reduced costs, although these studies have included patients with multiple diagnoses (e.g., delirium, depression). Additionally, these researchers report that a systematic approach to detection and intervention in delirium from multiple causes can be less successful than situations in which a single specific etiology can be identified.17 By contrast, Cole18 found psychiatric consultation to be superior to a multidisciplinary geriatric team approach in treating individuals with depression and delirium.
As part of a larger study to validate a previously reported preoperative risk stratification index used to identify patients likely to develop delirium after major elective surgery, we collected data on the LOS and costs of care. We theorized that the impact of this complication would not be uniform among the many forms of services typically provided to a hospitalized patient. Identifying areas of greatest financial impact might then provide better insights into the importance of this complication and the need for more effective, targeted interventions. The purpose of this report, therefore, is to explore the impact and relative contribution of postoperative delirium to costs from various hospital cost centers.
|
METHODS
|
Patient Selection and Study Procedures
During preoperative evaluation in the internal medicine clinic, we screened 563 patients consecutively scheduled for elective, inpatient, noncardiac surgical procedures. All participants signed a written informed consent form after full explanation of this internal reviewboard-approved project. Patients were at least 50 years old at the time of medical assessment for elective noncardiac surgery and were excluded if there was evidence of severe dementia or current delirium based on DSM-IV criteria. All patients had a predicted LOS greater than 2 days and all spoke English.
To replicate a previous report in which an association with the development of delirium was recognized, we collected preoperative electrolyte values including sodium, glucose, and potassium and used these values in our analysis of covariates.7 Data on postoperative laboratory values were not obtained. Patients and family members present at the preoperative assessment were asked about the presence of confusion, disorientation, or hallucinations. We excluded individuals reporting any of these factors within the past 3 months. In addition, we performed an extensive review of the medical history at the preoperative evaluation to determine the number and severity of comorbid conditions. The Charlson Comorbidity Index (CCI), a well-validated instrument, was used to reflect the impact of comorbid illness and also in the economic analyses to adjust results for mortality risk.19
As part of the preoperative physical examination, functional capacity was assessed with the Specific Activity Scale (SAS),20 an index commonly used to accurately quantify physical limitations in medically ill individuals. Among other activities, the SAS assesses an individual's ability to climb stairs, perform routine household chores, and walk, eat, or dress without assistance. In assessing cognitive function, the Confusion Assessment Method (CAM) was chosen.21 This instrument, developed by a panel of experts on delirium, is reported to have extremely high predictive accuracy for all aspects of delirium. To supplement this evaluation and to provide a preoperative baseline, cognitive function was also assessed using the Telephone Interview for Cognitive Status (TICS),22 a validated form of the Mini-Mental State Exam that does not require writing or drawing. The TICS has been described as highly sensitive and specific with high test-retest reliability.22
In addition to performing a chart review, a member of the study team screened each patient on Postoperative Days 1–4 using the CAM. For individuals with an abnormal screen (CAM score>8), a more detailed assessment of cognitive status was made using the TICS. Although, a decrement from preoperative baseline of 3 or more points in the TICS score provided a preliminary diagnosis of delirium, all diagnoses were confirmed using DSM-IV criteria. All evaluations were conducted at the patient's bedside by one of the authors, an internist, or a consultation-liaison fellow in psychiatry.
Data included in this report represent an economic analysis of information collected as part of a larger study aimed at validating a published clinical prediction rule identifying individuals at highest risk for postoperative delirium. To accomplish this goal, the clinical instruments used to assess cognitive function, comorbid illness, and functional status were identical to those used in the original study and were also used in our analyses as covariates.7
Economic Data and Definitions
Costs for patient care services were determined using a cost-allocation accounting system designed by Transition Systems International (TSI) used in our institution and others. This financial database includes professional billing data in addition to costs associated with hospital services and permits tracking for both charges and actual costs. Because the Cleveland Clinic is a fully integrated group practice and hospital, it was possible to include all costs in our analysis.
To distinguish between charges and costs and to permit a better understanding of the relative impact of postoperative delirium on specific aspects of hospital-based services, we briefly reviewed the terminology used in this accounting system. The first step in this process involved the generation of a summary of all service-related charges. Most institutions allow discounts or reductions to charges ultimately paid by the patient's insurance provider, leaving an amount known as "net revenue." From this is subtracted the "direct costs" or costs that are volume-dependent (e.g., expenses for medical and support personnel and consumable supplies). What remains is the "contribution margin" and from this is subtracted the "indirect costs" per patient, or nonvolume related expenses (e.g., utilities, facilities, administrative costs, and debt service). The remainder is known as the "net income."
Direct and indirect costs are divided further into two subcategories: professional (i.e., relating to services provided by physicians) and technical (i.e., remaining, nonphysician services). In addition to these summary categories, costs related to nursing, pharmacy (all medications during admission), pathology (all labs during admission), radiology (all imaging during admission), and physician costs (medical or surgical) can be identified.
Analysis
Data were entered using EPI-INFO (USD Inc., Stone Mountain, GA) and analyzed using SPSS/PC+ (SPSS Inc., Chicago, IL). Mean costs were compared between those developing delirium and those who did not using Student t-test. We used the Mann-Whitney test to assess differences in median LOS. To understand possible factors associated with the development of postoperative delirium, we calculated relative risk and 95% confidence intervals for several preoperative characteristics. To ascertain the effect of delirium on LOS, we used multiple regression analysis to control for the influence of important prognostic preoperative factors including an index of disease burden.
A second, exploratory subgroup analysis was performed to control for the effect of the surgical procedure on hospital costs and LOSs. In this analysis, we compared costs and hospital service utilization for individuals with or without postoperative delirium who had been admitted for major joint replacement of the lower extremity, the most commonly encountered diagnostic-related group (DRG). Finally, to determine if selection bias existed, costs for hospital services for all individuals admitted under the three most commonly represented DRGs in our study [major joint replacement, lower extremity (DRG 209) and back and neck procedures (DRGs 214 and 215)], were compared with those for individuals undergoing these procedures during the study period but not enrolled in our study.
|
RESULTS
|
Of the 563 patients approached to participate in this study, 63 eligible patients (11%) were either lost to follow-up or declined to participate. No differences were noted between participants and nonparticipants in the distribution of age, gender, race, or hospital LOS. Costs and data on LOS were available for all patients.
A total of 57 patients (11.4%) in the study cohort experienced delirium postoperatively. Factors associated with this complication are summarized in Table 1. Generally having had normal levels of sodium, glucose, and potassium before surgery were not found to be significant in predicting postoperative delirium. The mean LOS was 6.0 days for patients with delirium compared with 4.6 days in those who were unaffected (P<0.001). No significant differences in the mean ICU stay (0.68 vs. 0.28 days) were observed, although this was an uncommon occurrence in this sample. Direct and indirect technical costs were significantly increased (Table 2). Routine nursing costs, and those costs for pathology, medication, and total technical care were higher, on average, for patients with delirium (Table 3 and Table 4). Consultation costs (internal medicine, psychiatry and neurology) were higher among those who developed delirium (Table 5).
We created a multiple regression model to determine an association among LOS, mortality risk, and other covariates including age, gender, and functional status. No discernible association between delirium and LOS, total direct costs, or total indirect costs was observed.
Of the 500 in the sample, 148 orthopedic patients were admitted for DRG 209 (major joint replacement, lower extremity). Of these, 20 developed delirium. Although median LOS was noticeably longer among those who developed delirium, these differences did not achieve statistical significance (6 days vs. 5 days, P=0.056). Additionally, net revenue and direct and indirect costs were not significantly different among patients admitted under DRG 209 regardless of development of delirium. However, average medical professional costs (including consultations with internal medicine, psychiatry, neurology, etc.) were higher by an average of $161 (P=0.01) for those with delirium (n=20). Mean nonphysician technical costs ($60, P=0.001) were higher as well. Although ICU nursing costs ($86, P=0.025) were significantly higher for the group that developed delirium, this was because of a 4-day ICU stay for a single individual. Median ICU LOS between those that developed delirium and those that did not was not significantly different.
During this study period, 1,416 patients were admitted by neurosurgery and orthopedics departments under DRG 209 (major joint), DRG 214 (back with complications), or DRG 215 (back without complications) who were not included in our study. We had a total of 176 patients from these three DRG categories in our sample. From a cost perspective, our subgroup (n=176) differed from the larger three DRG populations (N=1,416) in a lower mean professional direct costs ($219, P<0.001) but higher mean nonphysician technical-direct costs ($595, P=0.001). Both mean and median LOS were longer for the 176 patients in the study cohort (P=0.017, P<0.001, respectively) compared with the other 1,416 patients.
|
DISCUSSION
|
Although the current study confirms earlier reports in identifying an increased LOS for patients who develop postoperative delirium, data on the financial toll and the attributable costs of postoperative delirium have not been available until now.4,7,8,10,11 For example, technical (nonphysician) costs may be driven higher in both volume and nonvolume related areas. Professional charges, which rise much less than technical ones, seem to rise primarily in the area of consultation (e.g., internal medicine, psychiatry, neurology, etc.). Increased intervention here may be helpful, according to Cole,18 if delirium exists. Although ward nursing costs increase, other aspects of nursing care are less affected. More research, like that reported by Heyman and Lombardo,15 is needed to reduce the number of cases requiring one-to-one care and to reduce the number of shifts in those that do still need that level of care.
In addition to a comparison of technical and professional costs among those who develop delirium, an analysis of the components of each of the costs may be useful. Specifically, it may be very beneficial to look at detailed costs associated with use of the hospital pharmacy. It may be that selected costs rise when the presence of specific complications are being assessed. A "shotgun" approach to evaluation should be avoided. However, if a specific cause of delirium can be recognized a greater rate of recovery is detected at 2 weeks.17
Higher pharmacy costs may reflect clinicians' efforts to control symptoms, but this is unlikely because only 20% of patients in general hospitals who might need neuroleptic drugs receive them.4 Higher pharmacy costs more likely reflect the well-recognized association between the number of medications prescribed and the incidence of delirium.23 Careful review of medication administration and a further analysis of drug utilization and its relationship with delirium could be valuable.
When restricting the cost analysis of delirium on surgical costs to a single DRG and a single surgical department, we attempted to control for the influence of procedure type on total hospital costs of care. Although most costs were not significantly different, medical professional costs were higher in patients who developed delirium. This may reflect fees of consultants called in to assess and recommend treatment for delirium. We suspect that the number of cases of delirium in this orthopedic subgroup was large enough to identify clinically significant differences with adequate power.
Among the limitations of our study is an unsuccessful attempt to separate the effects of important determinants of hospital costs from the development of postoperative delirium. Although these efforts at multiple regression analysis may have been limited by power rather than the true absence of an effect, further investigation will be necessary to establish this association more definitively. Secondly, the conclusions of our study may not be applicable to hospitals with dissimilar characteristics such as surgical volume, incorporation of care paths into inpatient nursing care, or routine use of preoperative evaluation and medical status optimization. It is important to note that overall costs in a tertiary-care hospital setting were not significantly higher for patients with delirium, although this might not be true for smaller general hospitals offering fewer services or performing fewer procedures. It is possible, for example, that patient volume at our institution may have resulted in a course of treatment that involved fewer costly interventions and greater efficiency.
These limitations notwithstanding, our study supports many others in identifying increased LOS for patients with delirium. Furthermore, we have demonstrated that it is possible to identify where increased costs occur. Recognizing patient characteristics reflecting vulnerability to acute cognitive impairment (such as diminished preoperative functional and cognitive status) and the cautious use of postoperative interventions (such as multiple medications, restraints, or indwelling bladder catheters that may precipitate delirium) may reduce the risk of delirium and its financial impact on selected hospital systems.24 Early psychiatric-psychosocial intervention may also play an especially pivotal role in reducing risk for postoperative delirium.25 Although future interventions directed at modifying risks for delirium may be designed to improve clinical outcomes and lower complication rates, our study suggests they may also result in substantially reduced health care costs as well.
|
REFERENCES
|
-
Trzepacz PT: Delirium: advances in diagnosis, pathophysiology, and treatment. Psychiatr Clin North Am 1996; 19(3):429–448
-
Williams-Russo P, Urquhart BL, Sharrock NE, et al: Postoperative delirium: predictors and prognosis in elderly orthopedic patients. J Am Geriatr Soc 1992; 40:759–767[Medline]
-
Gustafson Y, Brännström B, Berggren D, et al: A geriatric anesthesiologic program to reduce acute confusional states in elderly patients treated for femoral neck fractures. J Am Geriatr Soc 1991; 39:655– 662[Medline]
-
Francis J, Kapoor WN: Delirium in hospitalized elderly. J Gen Int Med 1990; 5:65–79[Medline]
-
van Hemert AM, van der Mast RC, Hengeveld MW, et al: Excess mortality in general hospital patients with delirium: a 5 year follow-up of 519 patients seen in psychiatric consultation. J Psychosomatic Research 1994; 38:339–346[CrossRef][Medline]
-
Schor JD, Levkoff SE, Reilly CH, et al: Risk factors for delirium in the hospitalized elderly. JAMA 1992; 267:827–831[Abstract]
-
Marcantonio ER, Goldman L, Mangione CM, et al: A clinical prediction rule for delirium after elective noncardiac surgery. JAMA 1994; 271:134–139[Abstract]
-
Gustafson Y, Berggren D, Brännström B, et al: Acute confusional states in elderly patients treated for femoral neck fracture. J Am Geriatr Soc 1988; 36:525– 530[Medline]
-
Saravay SM, Lavin M: Psychiatric cormorbidity and LOS in the general hospital: a critical review of outcome studies. Psychosomatics 1994; 35:233–252[Abstract/Free Full Text]
-
Thomas RI, Cameron DJ, Fahs MC: A prospective study of delirium and prolonged hospital stay. Arch Gen Psychiatry 1988; 45:937–940[Abstract]
-
Levkoff SE, Safran C, Cleary PD, et al: Identification of factors associated with the diagnosis of delirium in elderly hospitalized patients. J Am Geriatric Soc 1988; 36:1099–1104
-
Levkoff SE, Evans DA, Liptzin B, et al: Delirium. The occurrence and persistence of symptoms among elderly hospitalized patients. Arch Intern 1992; 152:334–340
-
Saravay SM: Psychiatric interventions in the medically ill: outcome and effectiveness research. Psychiatric Clinic of North America 1996; 19:1–14[CrossRef][Medline]
-
Levenson JL, Hamer RM, Rossiter LF: A randomized controlled study of psychiatric consultation guided by screening in general medical inpatients. Am J Psychiatry 1992; 149:631–637[Abstract/Free Full Text]
-
Heyman EN, Lombardo BA: Managing costs: the confused, agitated, or suicidal patient. Nursing Economics 1995; 13(2):107–118
-
Strain JJ, Lyons JS, Hammer JS, et al: Cost offset from a psychiatric consultation-liaison intervention with elderly hip fracture patients. Am J Psychiatry 1991; 148:1044–1049
-
Cole MG, Primeau FJ, Bailey RF, et al: Systematic intervention for elderly inpatients with delirium: a randomized trial. Can Med Assoc J 1994; 151(7):965–970
-
Cole MG, Fenton FR, Engelsmann F, et al: Effectiveness of geriatric psychiatry consultation in an acute care hospital: a randomized clinical trial. J Am Geriatr Soc 1991; 39:1183–1188
-
Charlson ME, Pompei P, Ales KL, et al: A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987; 40:373–383[CrossRef][Medline]
-
Goldman L, Hashimoto B, Cook EF, et al: Comparative reproducibility and validity of systems for assessing cardiovascular functional class: advantages of a new specific activity scale. Circulation 1981; 64:1227–1233
-
Inouye SK, van Dyck CH, Alessi CA, et al: Clarifying confusion: the Confusion Assessment Method; a new method for detection of delirium. Ann Intern Med. 1990; 113:941–948
-
Brandt J, Spencer M, Folstein M: The Telephone Interview for Cognitive Status. Neuropsychiat, Neuropsychol, Behavioral Neurol. 1988;1:111–117
-
Inouye SK, Charpentier PA: Precipitating factors for delirium in hospitalized elderly persons. JAMA 1996; 275:852–857[Abstract]
-
Muñoz E, Shamask F. Kassan M, et al: The costs and dynamics of surgical morbidity and mortality. Surgery 1986; 100:905–911[Medline]
-
Strain JJ, Hammer JS, Fulop G: AMP Task Force on psychosocial interventions in the general hospital inpatient setting: A review of cost-offset studies. Psychosomatics 1994; 25:253–262[Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
J. L. Rudolph, B. Ramlawi, G. A. Kuchel, J. E. McElhaney, D. Xie, F. W. Sellke, K. Khabbaz, S. E. Levkoff, and E. R. Marcantonio
Chemokines Are Associated With Delirium After Cardiac Surgery
J. Gerontol. A Biol. Sci. Med. Sci.,
February 1, 2008;
63(2):
184 - 189.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. L. Leslie, E. R. Marcantonio, Y. Zhang, L. Leo-Summers, and S. K. Inouye
One-Year Health Care Costs Associated With Delirium in the Elderly Population
Arch Intern Med,
January 14, 2008;
168(1):
27 - 32.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. L. Leslie, Y. Zhang, T. R. Holford, S. T. Bogardus, L. S. Leo-Summers, and S. K. Inouye
Premature Death Associated With Delirium at 1-Year Follow-up
Arch Intern Med,
July 25, 2005;
165(14):
1657 - 1662.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. M. Saravay, M. Kaplowitz, J. Kurek, D. Zeman, S. Pollack, S. Novik, S. Knowlton, M. Brendel, and L. Hoffman
How Do Delirium and Dementia Increase Length of Stay of Elderly General Medical Inpatients?
Psychosomatics,
June 1, 2004;
45(3):
235 - 242.
[Abstract]
[Full Text]
[PDF]
|
|
|
Get information about faster international access.
Privacy Policy
Copyright © 2001
Academy of Psychosomatic Medicine.
All rights reserved.
Home
| Search
| Current Issue
| Past Issues
| Subscribe
| All APPI Journals
| Help
| Contact Us
|
TOP
ABSTRACT
INTRODUCTION
