REVIEW

Economics and the Intensive Care Unit: A Conflict of Interests?

Kumanan Wilson and Deborah J. Cook

I NTENSIVE CARE UNITS are expensive and may consume close to 1% of GDP and 20% of

total hospital expenditures in the United States.‘J Since their development, their cost and utilization rates have increased dramatically. A combination of factors, including the adoption of expensive new technology as well as the highly skilled personnel they employ, have contributed to this escalation. In the current environment of fiscal restraint, pres- sures are being placed on intensive care units (ICUs) to control these costs. This has forced difficult decisions to be made regarding the type and quantity of care provided and to whom that care should be delivered. Increasingly, the disci- pline of health economics is being relied on to assist in making these decisions. However, eco- nomic recommendations designed to maximize health care for society can potentially be in conflict with the intensivist’s goal of maximizing the health care of the individual patient.

This article reviews some of the principles guiding the use of economic analysis in medicine. The cost of intensive care therapies are examined, and the ethics of using economics to ration care is discussed.

ECONOMIC ANALYSIS IN THE ICU

Economics deals with the problem of scarcity: having unlimited wants in the presence of limited resources. Issues of scarcity frequently arise in the ICU and have a profound effect on decision mak- ing. The decision to admit a patient to the final ICU bed is made with the awareness that another patient may be denied this bed. The decision to adopt a new expensive intervention is made recognizing that there may be less funding for existing interven- tions. The purpose of economic analyses is to determine the cost-to-benefit ratio for each of these decisions. In this way, the combination of decisions that maximize health care returns with given re- sources can be chosen.

Methods of Economic Analysis

Four forms of economic analysis are used in medicine: cost-minimization analysis, cost-effec- tiveness analysis, cost-utility analysis, and cost-

benefit analysis3 Of these, the two most commonly used are cost-effectiveness analysis and cost-utility analysis, both of which attempt to compare the incremental cost and the incremental health effects of two competing programs. In cost-effectiveness analysis, health effects are measured in natural units, such as life years saved or admission to hospital prevented. In cost-utility analysis, health effects are measured in utilities, such as quality adjusted life years (QALYs). Utilities are an at- tempt to measure an individual’s preference for a particular state of health (eg, a year of life on dialysis or a year of life after cerebrovascular accident) and are measured on a scale of 0 to 1.0, with 1 .O representing perfect health and 0 represent- ing death. Although utilities can be difficult to measure, this form of analysis has the advantage over cost-effectiveness analysis of being able to compare programs that produce different outcomes using one metric.

Considerable variability can exist in the way these analyses are performed. To be considered valid they should fulfill certain criteria.4 Good evidence from previous epidemiological studies for the effectiveness of the programs whose costs are being analyzed should be established. All important costs and outcomes should be included. The perspec- tive of the analysis (society, a third-party payer, a specific health care provider, or the patient) should be clearly specified. Costs and outcomes should be discounted over time (a method of correcting for society’s preference for having money and favor- able states of health sooner rather than later). The analyses should be incremental, that is the differ- ence in costs and outcomes of one program com- pared with another should be determined. Sensitiv- ity analyses should be performed for all areas of the analysis where there is potential for uncertainty.

From the Departments of Medicine and Clinical Epidemiol- ogy & Biostatistics, McMaster University, Hamilton, Ontario, Canada.

ReceivedApril 9, 1997. Accepted May 9, 1997. Address reprint requests to Deborah J. Cook, MD, Depart-

ment of Medicine, Division of Critical Care, St. Joseph’s Hospital, 50 Charlton Ave East, Hamilton, Ontario, Canada L8N 4A6.

Copyright 0 1997 by WB. Saunders Company 0883-9441/97/1203-0007$5.00/O

JournalofCriticalCare, Vol 12, No 3 (September), 1997: pp 147-151 147

148 WILSON AND COOK

How Can the Results of Economic Analyses Be Interpreted?

The results of an economic analysis can fall into four categories as demonstrated by Table 1.

An intervention that is determined to be more effective and less expensive than a competing strategy is referred to as being dominant and should be adopted. In contrast, a dominated strategy is one that is shown to be less effective and more expen- sive than another and should not be implemented. Conflicts arise when one intervention is both more effective and more costly than an alternative or when one intervention is less costly but less effective. In such situations, individual clinicians, institutions, or professional organizations may make different decisions depending on other factors, such as availability, access, experience, or preference.

Cost-effectiveness thresholds or league tables ranking cost-effectiveness ratios have been used to assist in making these decisions. One set of recom- mendations using thresholds suggests that strate- gies that cost less than $20,00O/QALY are “reason- able” to adopt, whereas those that cost more than $lOO,OOO/QALY are “unreasonable” to adopt. Cost- effectiveness ratios that lie between $20,000 and $lOO,OOO/QALY are considered to have moderate support for adoption5 It is important to recognize that these thresholds have been arbitrarily decided.

Arguments against the use of both thresholds and league tables to make decisions regarding selection of programs have been made. They include con- cerns about the validity of the long-term benefits and costs used in the studies, regional variability in costs, and uncertainty over the precision of utility calculations. Given the variable methods used in cost analysis, direct comparisons of cost-effective- ness ratios should be made with caution.(j

In the ICU there are particular problems with the use of cost-effectiveness ratios to allocate re- sources. First, the clinical benefits and harms of many ICU interventions have not been evaluated in rigorous studies. Second, the number of useful

Table 1. Results of an Economic Analysis

costs Less Costs More

More effective Dominant strategy ? Cost effectiveness

(should adopt) ratio of competing

interventions

Less effective 7 Cost effectiveness Dominated strategy

ratio of competing (should not adopt) intervention

Table 2. Cost-Effectiveness of ICU Therapies

Thrombolytic therapy with $21,20O/life year saved

streptokinase for suspected (United States)

MI in the elderly6 Thrombolytic therapy with $32,678/1ife year saved

TPA vstreptokinase for (United States)

acute Ml9 Air suspension beds to pre- Dominant strategy (Canada) vent pressure ulcersqO

Mask continuous positive Cost saving of $3899/patient

aitway pressure for severe (Australia)

cardiogenic pulmonary

edema” Protective sleeve pulmo- Cost-saving of $742/100

nary artery catheters’* catheter insertions (United States)

Abbreviations: Ml, myocardial infarction; TPA, tissue plas- minogen activator.

economic evaluations of ICU interventions is few and their methodologic quality has made clinical inferences difficult. This point was illustrated by an examination of 25 studies that evaluated the costs and benefits of adult ICU interventions. Of these, none met all four of the following minimal methodo- logic criteria: (1) described competing interven- tions adequately, (2) provided evidence of clinical efficacy of interventions, (3) used appropriate cost- ing methods, and (4) performed sensitivity analy- ses.’

Table 2 lists the cost-effectiveness ratios of some ICU interventions.

USING ECONOMICS TO RATION CARE

One of the principles of economics is the law of diminishing marginal returns (Fig l), which states that each successive unit of resource devoted towards a purpose yields progressively less benefit. This law is particularly relevant to resource applica- tion in ICU since “flat of the curve”13 medicine is often being practiced with very little benefit being derived from the resources that are invested. At- tempts have been made to identify these instances

“flat of the curve”

marginal improvement in health

resources devoted towards health care

Fig 1. Resources devoted to health care.

ECONOMICS AND CRITICAL CARE MEDICINE

of “low yield” care. Specifically, economic analy- ses have examined the cost-to-benefit ratio of ICU treatment for the elderly, patients with malignancy, patients with severe illness, and low-risk patients.

The aging of our population has prompted a closer examination of the cost of treating the elderly. Cohen et all4 retrospectively examined the costs of 45 patients of age 80 years and older who were admitted to a medical-surgical ICU and required mechanical ventilation for 3 or more days. They determined the cost per year of life saved for these patients to be between $5 1,854 and $75,090.i4 This cost increased dramatically if the patient required prolonged ventilation ($18 1,308/1ife year saved for those patients whose sum of age plus duration of ventilation equaled 100 or greater). However, Chelluri et ali5 compared outcomes in patients between 65 and 74 years old to those older than 75 years admitted nonelectively to a tertiary care ICU and noted no significant difference in mortality, quality of life, or costs between the two groups. The stronger predictor of poor prognosis in these patients was severity of illness as predicted by APACHE score.

ICU Costs of Treating Patients With Malignancy

Admission of patients with cancer to the ICU has also been subject to scrutiny given their compar- atively poor long-term prognoses. The cost of treating patients with solid tumors and hematologi- cal malignancies in the ICU was examined by Schapira et al. l6 The cost/life year gained was estimated to be $82,845 and $189,339, respec- tively.“j However, the costs for year of life gained at home increased to $95,142 for patients with solid tumors and to $449,544 for those with hematologi- cal cancers. In particular, it was noted that patients with hematolological cancers who required me- chanical ventilation had a particularly poor progno- sis with a mortality rate of 70%.

ICU Costs of Treating Patients With Poor Prognoses

It has been well established that a small percent- age of ICU patients contribute disproportionately to overall costs and fair poorly. In a study by Oye and Bellamy17 of 404 consecutive ICU admissions, the high cost 8% of patients consumed 50% of ICU resources and 70% of these high cost patients died. A British study by Ridley et all8 noted that the average daily cost for survivors was 300 pound

sterling less than for nonsurvivors. Costs were especially high for patients with sepsis or renal failure.

Attempts have been made to identify these patients at the time of admission using clinical assessment or predictive indices. Problems with this approach have been encountered. Detsky et ali9 noted that initial prognosis, as determined by housestaff, correlated well with survival but not with overall cost. The highest costs patients were those who were predicted to die who survived and those who were predicted to live who eventually died. This relationship of cost with uncertainty of prognosis has also been observed with the use of predictive indices such as APACHE and MPM scores.17Jo Patients with severe illness who are predicted to die often do so quickly and have short ICU stays as do patients who are predicted to do well. Therefore, the costs in these populations are relatively low. In contrast, the patients with interme- diate degrees of illness often have extended admis- sions and, consequently, high costs of care.

Other limitations of predictive indices for cost- control have been observed. Atkinson et a121 found that an algorithm based on a modified APACHE II score focusing on organ failure had the potential for reducing costs by identifying futile care but at the expense of 1 in 20 patients who would have survived if care had not been discontinued. Civetta et alz2 found that APACHE II scores were not useful for cost containment in a surgical ICU.

Although survival estimates at the time of admis- sion have their problems, the failure of patients to respond to therapy is associated with a poor prognosis and increased expense. Esserman et a123 found that a failure of APACHE score to change from day 1 to 5 was strongly associated with nonsurvival and high costs.

ICU Costs of Treating Low-Risk Patients

A high percentage of patients are admitted to the ICU primarily for monitoring. The potential for reducing costs by admitting some of these patients to less expensive wards has been examined. Zim- merman et alz4 looked at the possibility of admit- ting ICU patients to an intermediate care unit. In a study of 17,440 admissions at 40 US hospitals, they found that 46% of patients were admitted for monitoring and contributed to 15% of total day 1 to 7 costs. Seventy-seven percent of these patients

150 WILSON AND COOK

could be predicted by a prognostic model. The previously mentioned study by Oye and Bellamy17 noted that 45% of patients were admitted to the ICU for monitoring and that these patients had a 99% survival rate. It was estimated that ICU costs could be reduced by 10% if some of these patients were looked after in other wards. Latriano et a125 looked at the non-ICU care of ventilated patients who were hemodynamically stable. Costs were $380/day less in the special ventilation unit than in the ICUz5 with most savings secondary to reduced staffing. It is important to note that none of these studies specifically looked at the possible adverse affects of non-ICU care.

Summary

The use of economic analysis to justify rationing of care is controversial. Given the implications of such decisions, it is particularly important to recog- nize the challenges to interpreting these studies. However, there is evidence suggesting the potential for significant cost reduction by limiting low yield care. The area where it appears that the most cost-reduction could take place is in the subset of patients with prolonged ICU stays that ultimately die. At present, these patients cannot be accurately identified on admission. Dynamic assessments fo- cusing on the failure to respond to therapy may be more useful in this regard. The potential for cost reduction by reducing ICU admissions to low-risk patients primarily requiring monitoring needs to be examined further.

It should be recognized that any implementation of a “rationing” program will likely require exten- sive education of health care providers and the public, more widespread institution of advance directives, and explicit clinical policies imple- mented through practice guidelines. The success of practice guidelines in the critical care setting has been variable.26%27 If implemented, such guidelines should be evaluated for their effects on both costs and clinical outcomes.

ETHICAL CONSIDERATIONS OF THE USE OF ECONOMIC ANALYSES

Several ethical issues arise when economic analy- sis is used to direct practice in the ICU, particularly if it results in denying care. Economic analyses are intended to assist in finding ways to maximize the health care of society and not necessarily an individual patient. Their use to guide patient care is

most consistent with the ethical principal of justice, of which distributive justice (fair distribution of scarce resources) is a subcategory. Their recommen- dations can often conflict with other ethical prin- ciples, especially the principle of beneficence, which is usually considered at the individual pa- tient leve1.28

Intensivists are frequently confronted with the dilemma of how to resolve issues of distributive justice and beneficence when looking after their patients. Those who are primarily guided by the principle of beneficence will provide care to a patient as long as they believe there is some potential for benefit. Those who are guided by the principle of distributive justice will devote re- sources to a patient’s care up to the point that they believe that these resources may provide more assistance to other patients. Traditionally, it has been more the role of society (government, health care policy makers) to attend to issues of distribu- tive justice. However, increasingly intensivists are becoming involved in this area, either as policy makers themselves in hospital leadership positions or as physicians trying to ensure equal access to care for a serviced population.

CONCLUSION

Health economics is playing a more prominent role in critical care today. Properly used, it has the potential to improve the health of society by optimizing intensive care resource utilization. The first step in reducing spiraling ICU costs is to ensure that existing tests and interventions have evidence supporting their effectiveness demon- strated in rigorous clinical studies. Economic analy- sis can then be used to assist decision makers in choosing which of these tests and interventions to implement. This step has not been taken by most ICUs, because a large proportion of our diagnostic tests and interventions have been implemented while their effectiveness is in doubt.29 These deci- sions will always need to be made in light of local availability, access, technical expertise, and particu- lars of different health care settings.

More research and experience is needed to evaluate how best to use health economics in the delivery of intensive care. As health care costs continue to increase, the need for the ICU team to be fiscally responsible while embracing our role as caregivers is of paramount importance.

ECONOMICS AND CRITICAL CARE MEDICINE 151

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