Conservative versus liberal oxygen therapy in hypoxic ischemic encephalopathy following cardiac arrest: a trial-based cost-effectiveness analysis.

BACKGROUND

The cost-effectiveness of conservative versus liberal oxygen therapy in critically ill adults with post-cardiac arrest hypoxic ischemic encephalopathy is unknown.

METHODS

A cost-effectiveness analysis alongside the LOGICAL trial was conducted from a health system perspective. Conservative oxygen targeted arterial oxygen saturation (SpO2) of 90-95% using the lowest fraction of inspired oxygen (FiO2), while liberal oxygen had no upper SpO2 limit and a minimum FiO2 of 0.3 during invasive ventilation. Patient-level data were analyzed from 53 intensive care units (ICU) in Australia, New Zealand, and Ireland. Costs (2024, US$) included ICU, ward, and inpatient rehabilitation stays. Health outcomes included favorable functional outcome (Glasgow Outcome Scale-Extended score 5-8) and quality-adjusted life years (QALYs) at 180 days derived from EQ-5D-5L. Uncertainty was explored using bootstrapping. Discounting was not applied.

RESULTS

Among 1821 participants (median age 62 years; 28.6% female), 873 were randomized to conservative and 948 to liberal oxygen. Mean per-patient cost was $33,629 ($33,517) in the conservative group, with an incremental cost of -$1392 (95% CI, -$4696 to $1911). Favorable functional outcome occurred in 38.2% with conservative oxygen (risk difference, -1.5 percentage points; 95% CI, -6.1 to 3.2). Incremental QALYs were -0.002 (95% CI, -0.013 to 0.008). Conservative oxygen was associated with cost-savings of $635,151 per QALY forgone with considerable uncertainty (>55% bootstrapped replications). Incremental net monetary benefit was $1173 (95% CI, -$2096 to $4442) at $100,000 per QALY.

CONCLUSIONS

Conservative oxygen was associated with modest cost savings and small differences in health outcomes, with no clear economic advantage over liberal oxygen.

Trial number: ACTRN12621000518864.