Search tips
Search criteria 


Logo of bmjThis ArticleThe BMJ
BMJ. 2007 December 1; 335(7630): 1103–1104.
Published online 2007 November 1. doi:  10.1136/bmj.39378.654329.80
PMCID: PMC2099542

Deciding who to admit to a critical care unit

Eddy Fan, instructor and Dale M Needham, assistant professor

Scarce resources may cause doctors to be pessimistic about prognosis and refuse critical care admissions

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. The incidence of COPD is rising, and the World Health Organization estimates that it will be the fourth leading cause of death globally by 2030.1 In this week's BMJ, Wildman and colleagues report the differences between actual survival and survival predicted by a doctor in people with asthma or COPD admitted to intensive care.2 This is an important matter to investigate, because people with asthma and COPD who have acute exacerbations that require admission to intensive care have high short term mortality.3 4

Using data from 832 admissions for asthma or COPD in 95 intensive care units and high dependency units in the United Kingdom, the authors found that predicted survival was lower than actual survival (49% v 62%) 180 days after admission. This “prognostic pessimism” was present in the overall sample and for most subgroups of people. The absolute difference between predicted and actual survival was >30% in people with the lowest predicted survival. The authors suggest that the scarcity of intensive care resources in the UK may contribute to doctors' inaccurate predictions of survival because such prognostic pessimism may stop them feeling that they are denying treatable patients potentially life saving treatment. Is such prognostic pessimism a disease that needs treatment (by improving doctors' prognostic skills) or a symptom of an underlying problem with the healthcare system, such as scarce intensive care resources?

Decisions about the use of life sustaining treatment are complex, imprecise, and need to balance the potential risks and benefits to each critically ill person. Predicting the probability of short term survival is important when assessing the benefits of intensive care. Despite knowledge of important prognostic factors,3 previous studies have also shown significant variability in doctors' estimates of survival for people with an exacerbation of COPD who need mechanical ventilation.5 6

Mortality should not be the only consideration when deciding about admission to intensive care. Providing doctors, patients, and families with more accurate estimates of survival during serious illness did not strongly influence the medical decisions made in a large study from the United States.7 Quality of life after intensive care is an important consideration also,8 especially as—for instance—nearly 90% of seriously ill people would rather die than survive with severe cognitive impairment.9 These factors may have had an effect on doctors' predicted prognosis, but this cannot be determined on the basis of data provided in Wildman and colleagues' study.1 Like predicting patient mortality, the ability of doctors and nurses to predict quality of life after intensive care is unsatisfactory.10

Making decisions about admission to intensive care is even more complex than determining the benefits and risks to an individual patient when resources are scarce. This may be especially relevant in the UK and southern Europe, where intensive care beds are often lacking.11 The authors speculate that in the face of chronically scarce resources, doctors may develop prognostic pessimism, which leads them to refuse seriously ill patients admission to intensive care. A study comparing admission to intensive care in Canada and the US reported that Alberta had 50% fewer intensive care beds per capita than did western Massachusetts. In the Canadian setting, admission to intensive care was more often denied to elderly patients with chronic medical conditions who were thought unlikely to benefit from such care.12 Although this illustrates rationing of intensive care on the basis of the availability of resource in Canada, it is unclear whether prognostic pessimism was a factor in the decision making process. Furthermore, the study found no significant difference in hospital mortality despite rationing of intensive care— hospital mortality was not reported in the study by Wildman and colleagues.1

Future studies of doctors' prognostic accuracy in jurisdictions with fewer limitations in intensive care resources may allow Wildman and colleagues' work to be interpreted within a broader context. This will determine whether prognostic pessimism requires intervention aimed at doctors or at underlying healthcare systems that have inadequate provision of critical care services.


This article was published on on 1 November 2007


Competing interests: None declared.

Provenance and peer review: Commissioned; not externally peer reviewed.


1. World Health Organization. Chronic obstructive pulmonary disease (COPD): burden. 2007.
2. Wildman MJ, Sanderson C, Groves J, Reeves BC, Ayres J, Harrison D, et al. Prognostic pessimism for patients with chronic obstructive pulmonary disease (COPD) or asthma admitted to intensive care in the UK: multicentre observational cohort study. BMJ 2007. doi: 10.1136/bmj.39371.524271.55
3. Connors AF Jr, Dawson NV, Thomas C, Harrell FE Jr, Desbiens N, Fulkerson WJ, et al. Outcomes following acute exacerbations of severe chronic obstructive lung disease. Am J Respir Crit Care Med 1996;154:959-67. [PubMed]
4. Gupta D, Keogh B, Chung KF, Ayres JG, Harrison DA, Goldfrad C, et al. Characteristics and outcome for admissions to adult, general critical care units with acute severe asthma: a secondary analysis of the ICNARC case mix programme database. Crit Care 2004;8:R112-21. [PMC free article] [PubMed]
5. Pearlman RA. Variability in physician estimates of survival for acute respiratory failure in chronic obstructive lung disease. Chest 1987;91:515-21. [PubMed]
6. Wildman M, O'Dea J, Kostopolou O, Tindall M, Walia S, Khan Z. Variation in intubations decisions for patients with chronic obstructive pulmonary disease in one critical care network. Q J Med 2003;96:583-91.
7. The SUPPORT Principal Investigators. A controlled trial to improve care for seriously ill hospitalized patients: the study to understand prognoses and preferences for outcomes and risks of treatments (SUPPORT). JAMA 1995;273;1591-8.
8. Dowdy DW, Eid MP, Sedrakyan A, Mendez-Tellez PA, Pronovost PJ, Herridge MS, et al. Quality of life in adult survivors of critical illness: a systematic review of the literature. Intensive Care Med 2005;31:611-20. [PubMed]
9. Fried TR, Bradley EH, Towle VR, Allore H. Understanding the treatment preferences of seriously ill patients. N Engl J Med 2002;346:1061-6. [PubMed]
10. Frick S, Uehlinger DE, Zuercher Zenklusen RM. Medical futility: predicting outcome of intensive care unit patients by nurses and doctors—a prospective comparative study. Crit Care Med 2003;31:456-61. [PubMed]
11. Vincent JL. Forgoing life support in western European intensive care units: the results of an ethical questionnaire. Crit Care Med 1999;27:1626-33. [PubMed]
12. Rapoport J, Teres D, Barnett R, Jacobs P, Shustack A, Lemeshow S, et al. A comparison of intensive care utilization in Alberta and western Massachusetts. Crit Care Med 1995;23:1336-46. [PubMed]

Articles from The BMJ are provided here courtesy of BMJ Publishing Group