Long-term resource use, quality of life, and cost-effectiveness of liberal and conservative fluid strategies in acute lung injury

Introduction

The objective was to estimate differences in long-term outcomes and resource use (RU) and to determine the marginal cost-effectiveness (CE) ratio of care using a liberal (LIB) or conservative (CON) fluid strategy for acute lung injury (ALI) in the NHLBI ARDS Network multicenter Fluid and Catheter Treatment Trial.

Methods

We used data on RU and outcomes from a subset of 655 participating in postdischarge follow-up. We estimated costs using Medicare cost-to-charge ratios and fee schedules. CE ratios and 95% confidence ellipses were generated by Monte-Carlo simulation (Figure 1). We estimated the postdischarge RU and utility up to 1 year from interviews, post-1-year survival from age-matched, sex-matched and race-matched life tables, and post-1-year costs from the Medical Expenditure Survey. We assumed mean utility at 1 year to be constant thereafter. We projected costs to the year 2008 and discounted future costs and outcomes at 3% per annum. Costs are in 2007 US$.

Figure 1

QALY, quality of life years.

Results

Hospital costs were available for 633 subjects and were similar for LIB (n = 310, $97,100) and CON (n = 323, $89,000) (P = not significant). Post discharge to 1 year costs of LIB (n = 208) were similar to those of CON (n = 221) ($53,600 vs $52,600, P = not significant) for those discharged alive, and $41,100 vs $39,000 for all subjects. Post 1 year costs were similar. Mortality increased from 26.9% (LIB) and 24.5% (CON) at 60 days to 35.6% and 32.1% at 1 year (P = 0.31). Home oxygen use was 32.2% and 28.5% for LIB and CON (P = not significant) and 15.4% and 14.0% at 1 year (P = not significant). Admission to a rehabilitation facility (34.1% and 29.4%) and rehospitalization (44.2% and 46.2%) were common in year 1 (P = not significant). Quality of life was low throughout follow-up, but did improve from 60 days (0.50 and 0.48) to 1 year (0.67 and 0.59) (P = not significant between LIB and CON).

Conclusion

Subjects surviving ALI have considerable postdischarge RU and impaired quality of life. No single domain of outcome was significantly affected by the fluid strategy but observed values were generally better with CON. CON had a better CE profile than LIB.