Purpose: Many patients with acute respiratory failure die despite prolonged and costly treatment. Our objective was to estimate the cost-effectiveness of providing rather than withholding mechanical ventilation and intensive care for patients with acute respiratory failure due to pneumonia or acute respiratory distress syndrome.
Subjects and methods: We studied 1,005 patients enrolled in a five-center study of seriously ill patients (the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments [SUPPORT]) with acute respiratory failure (pneumonia or acute respiratory distress syndrome and an Acute Physiology Score > or =10) who required ventilator support. We estimated life expectancy based on long-term follow-up of SUPPORT patients. Utilities were estimated using time-tradeoff questions. Costs (in 1998 dollars) were based on hospital fiscal data and Medicare data.
Results: Of the 963 patients who received ventilator support, 48% survived for at least 6 months. At 6 months, survivors reported a median of 1 dependence in activities of daily living, and 72% rated their quality of life as good, very good, or excellent. Among the 42 patients in whom ventilator support was withheld, the median survival was 3 days. Among patients whose estimated probability of surviving at least 2 months from the time of ventilator support ("prognostic estimate") was 70% or more, the incremental cost per quality-adjusted life-year (QALY) saved by providing rather than withholding ventilator support and aggressive care was $29,000. For medium-risk patients (prognostic estimate 51% to 70%), the incremental cost-effectiveness was $44,000 per QALY, and for high-risk patients (prognostic estimate < or =50%), it was $110,000 per QALY. When assumptions were varied from 50% to 200% of baseline estimates, the results ranged from $19,000 to $48,000 for low-risk patients, from $29,000 to $76, 000 for medium-risk patients, and from $67,000 to $200,000 for high-risk patients.
Conclusions: Ventilator support and intensive care for acute respiratory failure due to pneumonia or acute respiratory distress syndrome are relatively cost-effective for patients with >50% probability of surviving 2 months. However, for patients with an expected 2-month survival < or =50%, the cost per QALY is more than threefold greater at >$100,000.