BMJ  2004;329:425 (21 August), doi:10.1136/bmj.329.7463.425

Paper

National questionnaire survey on what influences doctors' decisions about admission to intensive care

¹ Pain and Palliative Care Consultation, Division of Clinical Pharmacology and Toxicology, Geneva University Hospitals, CH-1211 Geneva 14, Switzerland, ² Quality of Care Unit, Geneva University Hospitals, ³ Medical Intensive Care Division, Geneva University Hospitals

Abstract

Objectives To determine what influences doctors' decisions about admission of patients to intensive care.

Design National questionnaire survey using eight clinical vignettes involving hypothetical patients.

Setting Switzerland.

Participants 402 Swiss doctors specialising in intensive care.

Main outcome measures Rating of factors influencing decisions on admission and response to eight hypothetical clinical scenarios.

Results Of 381 doctors agreeing to participate, 232 (61%) returned questionnaires. Most rated as important or very important the prognosis of the underlying disease (82%) and of the acute illness (81%) and the patients' wishes (71%). Few considered the important socioeconomic circumstances of the patient (2%), religious beliefs (3%), and emotional state (6%). In the vignettes, underlying disease (cancer versus non-cancerous disease) was not associated with admission to intensive care, but four other factors were: patients' wishes (odds ratio 3.0, 95% confidence interval 2.0 to 4.6), upbeat personality (2.9, 1.9 to 4.4), younger age (1.5, 1.1 to 2.2), and a greater number of beds available in intensive care (1.8, 1.2 to 2.5).

Conclusions Doctors' decisions to admit patients to intensive care are influenced by patients' wishes and ethically problematic non-medical factors such as a patient's personality or availability of beds. Patients with cancer are not discriminated against.

Introduction

Although guidelines have been developed to help doctors decide on who to admit to intensive care, they may be difficult to put into practice.¹ Several characteristics of patients influence admission to intensive care, such as age and severity of illness.^{1 2} Availability of beds has been inconsistently associated with triage decisions.^{2 3} Cognitive factors may also influence decisions, including biases in doctors' processing of information.^{4 5} More specifically, and regardless of prognosis, patients with cancer may have more do not resuscitate orders and receive less cardiopulmonary resuscitation, mechanical ventilation, and intensive care.^6-10 We assessed what influences doctors' decisions to admit patients to intensive care. In particular we sought to determine if there was a bias against patients with cancer.

Methods

We carried out a questionnaire survey of all Swiss doctors who specialised in intensive care. We assessed the importance of potential determinants of admission to intensive care by asking respondents to rate 19 factors associated with patients or the intensive care setting and by asking them to decide on whether to admit to intensive care eight hypothetical patients who had been admitted through the emergency department and described in eight clinical vignettes.

Clinical vignettes
Two scenarios in the vignettes were identical for all respondents. One was designed to elicit admission to intensive care (diabetic patient with myocardial infarction) and the other refusal (acute respiratory failure warranting mechanical ventilation in a patient with relapsing leukaemia). In six vignettes potentially important features of the clinical situation were manipulated. Each scenario tested three dichotomous factors combined in a factorial design resulting in eight versions of each scenario.

The influence of cancer was assessed in all six vignettes by comparing cancer with non-cancerous disease with a similar prognosis. Two scenarios tested the influence of the patient's age and wishes, two evaluated the patient's personality and the availability of intensive care beds, one assessed the patient's financial autonomy, one assessed the patient's social commitment, and two included the family's wishes, either as an explicit request or as a non-verbal attitude.

We balanced the sets of scenarios in terms of risk factor profile. Thus each questionnaire included three vignettes with cancer and three with a non-cancerous disease; if one scenario contained the combination of cancer, younger age, and one intensive care bed, then another presented the opposite combination. Eight versions of the questionnaire were created, and each participant was randomly allocated to one of these.

Statistical analysis
We computed means and standard deviations for continuous variables and distributions for frequency of categorical variables. The rating of factors influencing triage was dichotomised (scores 4-5 1-3).

Each scenario was analysed separately. We built a logistic regression model where the admission was the dependent variable and the three dichotomous factors the independent variables. Adjusted odds ratios for admission were obtained from these models. We then performed a pooled analysis for the factors tested in several vignettes. For factors appearing in two scenarios, such as age, we computed the McNemar matched odds ratios by cross tabulating decisions on admission for each matched pair of scenarios. The number of admissions for patients with cancer and non-cancerous disease was compared for each respondent using a Wilcoxon matched pair test.

Results

Overall, 232 of 381 doctors (61%) returned completed questionnaires (see bmj.com for details of the respondents). Among the factors influencing decisions on admission to intensive care, most doctors rated as important or very important the prognosis of the acute illness and of the underlying disease and the patients' wishes (figure). Half considered availability of beds as important.

View larger version (43K): [in this window] [in a new window]   Doctors' ranking of factors when assessing patients for admission to intensive care

 

Analysis of scenarios
One scenario (myocardial infarction) was designed to elicit an acceptance rate close to 100%; 217 respondents (94%) chose to admit the patient. In another scenario (respiratory failure in the presence of relapse with acute leukaemia) refusal was expected from most doctors yet 190 (82%) admitted the patient.

The six remaining vignettes were answered by 213 (92%) doctors. The mean number of patients admitted to intensive care was 3.3 (SD 1.3) out of six. The overall proportion of admissions across all variations of a given scenario ranged from 46% (fever, dysuria, and renal failure) to 66% (upper gastrointestinal bleeding).

Admission rates varied significantly according to at least one experimentally manipulated factor (table). Having cancer did not influence the probability of admission in five scenarios. A patient with breast cancer presenting with haemolytic uraemic syndrome was, however, three times less likely to be admitted to intensive care than a patient with AIDS with the same condition.

View this table: [in this window] [in a new window]   Influence of factors assessed in hypothetical scenarios on probability of being admitted to intensive care

 

Certain personality traits and the patient's wish to receive maximal treatment were associated with increased odds of admission. Patients described as upbeat and sociable or strong and courageous were more likely to be admitted than patients described as sad and withdrawn or anxious and discouraged. The patient's means of living did not affect the probability of admission, but social involvement did. Younger age was associated with a slightly higher admission rate. Availability of three beds was related to a higher probability of a patient being admitted. An explicit request from the family increased the chances of admission whereas a non-verbal emotional attachment did not.

Discussion

Specific factors influence doctors' decisions to admit patients to intensive care. Some factors, such as consideration for the patient's wishes, agree with current recommendations. Others, such as a patient's personality, are ethically questionable. Moreover, we found a discrepancy between the acknowledged importance of some factors and the importance as shown by the hypothetical clinical scenarios, suggesting that unconscious processes may be at work, leading to biased decisions.

An important finding was the absence of discrimination against patients with cancer. Medical progress in the treatment of cancer and its complications gives the hope of improved survival and better quality of life. Thus doctors' perception of the therapeutic options for malignancies may be changing. Insufficient knowledge rather than bias would account for the difference in admission rates between the patient with AIDS presenting with haemolytic uraemic syndrome and the patient with breast cancer and the same condition.

Most doctors considered of paramount importance the prognosis of the acute illness and of the underlying disease. These two factors belong to the basic principles of triage, and studies have shown that they are associated with admission to intensive care.^1-3

Patients' wishes were considered important by most respondents, and in the experimental part of the study were strongly related to admission. This sharply contrasts with the finding that the patient's personality equally influenced doctors' decisions. The preference to admit patients with a positive attitude was not conscious as respondents rated the patient's emotional state low among the determinants for admission. Similarly, a patient described as socially active was more likely to be admitted. These results raise ethical concerns.

Availability of beds was considered important and was correlated with the decision to admit. As with our study, previous studies have suggested that fewer patients are admitted when beds are scarce.² Doctors also recognised different aspects of rationing such as nursing workload and the optimal use of available beds.¹¹ Age was moderately associated with admission to intensive care.

Doctors' decisions varied according to the family's wishes and attitudes. An explicit request was related to the decision to admit to intensive care but apparent emotional attachment was not. This raises the issues of whether the patient's best interests were the doctor's prime concern in both situations and whether the doctor should actively seek the preferences of the family. Decision making in the presence of an incompetent patient is problematic. The accuracy of proxy judgments is generally poor,¹² but doctors' predictions of the patient's preferences are worse.¹³ Family members can also exert pressure on the doctor,¹⁴ and they often fail to fully understand their relative's state of health and related issues.¹⁵

What is already known on this topic Biases and practical constraints may influence doctors' decisions on admitting patients to intensive care The relative importance of these factors is not well known What this study adds Patients' wishes and ethically questionable factors such as a patient's personality or availability of beds influence doctors' decisions on admission to intensive care Unconcious value judgments may lead to an unfair allocation of intensive care beds

The main limitation of our study is the possible discrepancy between doctors' decisions in practice and their answers to vignettes with hypothetical patients. However, the validity of the decisions is supported by the overall admission rate of about 50% and the respondents' straightforward answers. The high admission rate of the patient with relapsing leukaemia may seem surprising, but the respondents' comments about having little choice because the patient was mechanically ventilated, further indicate that their answers were based on their everyday practice. The response rate of 61% raises the possibility of non-response bias, particularly for descriptive variables such as the rating of factors influencing decisions on admission. Because response rates were similar for the eight versions of the questionnaire, a bias is unlikely in measures of association between the experimentally manipulated factors and the reported decisions.

In conclusion, doctors do not discriminate against patients with cancer when deciding on admission to intensive care. The decision making process is influenced by the patient's wishes and ethically questionable factors such as the patient's personality. The medical community must be aware of the existence of unconscious value judgments leading to possible biased decisions for admissions to intensive care.

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This is the abridged version of the article. The full version appears on bmj.com

Contributors: See bmj.com

Funding: Swiss Society of Intensive Care Medicine.

Competing interests: None declared.

Ethical approval: Clinical ethics committee of the Geneva University Hospitals.

References

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2. Sprung CL, Eidelman LA. Triage decisions for intensive care in terminally ill patients. Intensive Care Med 1997;23: 1011-4.[Medline]
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4. Eisenberg J. Sociologic influences on decision-making by clinicians. Ann Intern Med 1979;90: 957-64.
5. Redelmeier D, Ferris L, Tu J, Hux J, Schull M. Problems for clinical judgement: introducing cognitive psychology as one more basic science. Can Med Assoc J 2001;164: 358-60.[Free Full Text]
6. Lawrence V, Clark G. Cancer and resuscitation. Does the diagnosis affect the decision? Arch Intern Med 1987;147: 1637-40.[Abstract/Free Full Text]
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8. Wachter R, Luce J, Hearst N, Lo B. Decisions about resuscitation: inequities among patients with different diseases but similar prognoses. Ann Intern Med 1989;111: 525-32.
9. Tanvetyanon T, Leighton J. Life-sustaining treatments in patients who died of chronic congestive heart failure compared with metastatic cancer. Crit Care Med 2003;31: 60-4.[CrossRef][Medline]
10. Claessens MT, Lynn J, Zhong Z, Desbiens NA, Phillips RS, Wu AW, et al. Dying with lung cancer or chronic obstructive pulmonary disease: insights from SUPPORT study (Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments). J Am Geriatr Soc 2000;48: S146-53.[Web of Science][Medline]
11. Tarnow-Mordi WO, Hau C, Warden A, Shearer AJ. Hospital mortality in relation to staff workload: a 4-year study in an adult intensive care unit. Lancet 2000;356: 185-9.[CrossRef][Web of Science][Medline]
12. Suhl J, Simons P, Reedy T, Garrick T. Myth of substituted judgment. Surrogate decision making regarding life support is unreliable. Arch Intern Med 1994;154: 90-6.[Abstract/Free Full Text]
13. Coppola KM, Ditto PH, Danks JH, Smucker WD. Accuracy of primary care and hospital-based physicians' predictions of elderly outpatients' treatment preferences with and without advance directives. Arch Intern Med 2001;161: 431-40.[Abstract/Free Full Text]
14. Ely JW, Peters PG Jr, Zweig S, Elder N, Schneider FD. The physician's decision to use tube feedings: the role of the family, the living will, and the Cruzan decision. J Am Geriatr Soc 1992;40: 471-5.[Web of Science][Medline]
15. Azoulay E, Chevret S, Leleu G, Pochard F, Barboteu M, Adrie C, et al. Half the families of intensive care unit patients experience inadequate communication with physicians. Crit Care Med 2000;28: 3044-9.[CrossRef][Web of Science][Medline]

(Accepted 16 June 2004)

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