Objective: To estimate the cost effectiveness of aggressive care for patients with nontraumatic coma.
Design: Cost-effectiveness analysis.
Setting: Five academic medical centers.
Patients: Patients with nontraumatic coma enrolled in the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT). Patients with reversible metabolic causes of coma such as diabetic ketoacidosis or uremia were excluded.
Measurements: We calculated the incremental cost effectiveness of continuing aggressive care vs. withholding cardiopulmonary resuscitation and ventilatory support after day 3 of coma. We estimated life expectancy based on up to 4.6 yrs of follow-up. Utilities (quality-of-life weights) were estimated using time-tradeoff questions. Costs were based on hospital fiscal data and Medicare data. Separate analyses were conducted for two prognostic groups based on five risk factors assessed on day 3 of coma: age ≥70 yrs, abnormal brainstem response, absent verbal response, absent withdrawal to pain, and serum creatinine ≥132.6 μmol/L (1.5 mg/dL).
Results: For the 596 patients studied, the median (25th, 75th percentile) age was 67 yrs (range, 55–77), and 52% were female. By 2 months after enrollment, 69% had died, 19% were severely disabled, 7% had survived without severe disability, and 4% had survived with unknown functional status. The incremental cost effectiveness of the more aggressive care strategy was $140,000 (1998 dollars) per quality-adjusted life year (QALY) for high-risk patients (3–5 risk factors, 93% 2-month mortality) and $87,000/QALY for low-risk patients (0–2 risk factors, 49% mortality). In sensitivity analyses, the incremental cost per QALY did not fall below $50,000/QALY, even with wide variation in our baseline estimates.
Conclusions: Continuing aggressive care after day 3 of nontraumatic coma is associated with a high cost per QALY gained, especially for patients at high risk for poor outcomes. Earlier decisions to withhold life-sustaining treatments for patients with very poor prognoses may yield considerable cost savings.