An economic evaluation of prolonged mechanical ventilation

Patients who receive prolonged mechanical ventilation have high resource utilization and relatively poor outcomes, especially the elderly, and are increasing in number. The economic implications of prolonged mechanical ventilation provision, however, are uncertain and would be helpful to providers and policymakers. Therefore, we aimed to determine the lifetime societal value of prolonged mechanical ventilation.

Adopting the perspective of a healthcare payor, we developed a Markov model to determine the cost effectiveness of providing mechanical ventilation for at least 21 days to a 65-yr-old critically ill base-case patient compared with the provision of comfort care resulting in withdrawal of ventilation. Input data were derived from the medical literature, Medicare, and a recent large cohort study of ventilated patients.

We determined lifetime costs and survival, quality-adjusted life expectancy, and cost effectiveness as reflected by costs per quality-adjusted life-year gained. Providing prolonged mechanical ventilation to the base-case patient cost "dollars"55,460 per life-year gained and "dollars"82,411 per quality-adjusted life-year gained compared with withdrawal of ventilation. Cost-effectiveness ratios were most sensitive to variation in age, hospital costs, and probability of readmission, although less sensitive to postacute care-facility costs. Specifically, incremental costs per quality-adjusted life-year gained by prolonged mechanical ventilation provision exceeded "dollars"100,000 with age >or=68 and when predicted 1-yr mortality was >50%.

The cost effectiveness of prolonged mechanical ventilation provision varies dramatically based on age and likelihood of poor short- and long-term outcomes. Identifying patients likely to have unfavorable outcomes, lowering intensity of care for appropriate patients, and reducing costly readmissions should be future priorities in improving the value of prolonged mechanical ventilation.