Costs, quality-adjusted life years, and value-of-information of different thresholds for the initiation of invasive ventilation in hypoxemic respiratory failure

ObjectiveTo estimate costs, quality-adjusted life-years, and the value of undertaking a future randomized controlled trial for different oxygenation thresholds used to initiate invasive ventilation in hypoxemic respiratory failure. DesignModel-based cost-utility estimation with individual-level simulation and value-of-information analysis. SettingCritical care units. ParticipantsAdults admitted to critical care receiving non-invasive oxygen. InterventionsWe compared four strategies: initiation of invasive ventilation at thresholds of saturation-to-inspired oxygen fraction ratio (SF) < 110, < 98, or < 88, and usual care. Main resultsAn invasive ventilation initiation threshold of SF < 110, compared to usual care, resulted in more predicted invasive ventilation (62% vs 31%), hospital survival (78.4% vs 75.5%), quality-adjusted life years (QALYs) (8.48 vs 8.34), and lifetime costs (86,700 Canadian dollars (CAD) vs 75,600 CAD). Among the four strategies, threshold SF < 110 had the highest expected net monetary benefit (761,000 CAD), but there was significant uncertainty, because all four strategies had similar probability (range: 23.5% to 27.5%) of having the best net monetary benefit. The expected value to society over the next 10 years of a 400-person randomized trial of oxygenation thresholds was 4.27 billion CAD, and remained high (2.64 billion CAD) in a scenario analysis considering a hypothetical threshold that resulted in less invasive ventilation and similar survival compared to usual care. ConclusionThe preferred threshold to initiate invasive ventilation in hypoxemic respiratory failure is uncertain. It would be highly valuable to society to identify thresholds that, in comparison to usual care, either improve survival or reduce invasive ventilation without reducing survival. Key points QuestionWhat are the costs and quality-adjusted life-years associated with different oxygenation thresholds for initiating invasive ventilation, and what is the expected value to society of a randomized controlled trial? FindingsIn this health economic evaluation comparing usual care to three different thresholds for initiating invasive ventilation in hypoxemic respiratory failure based on the saturation-to-inspired oxygen fraction ratio (SF), we found that threshold SF < 110 had the highest expected quality-adjusted life-years and net monetary benefit, despite increased predicted invasive ventilation use. However, there was significant residual uncertainty, and the expected value to society of a 400-person randomized trial to compare thresholds for initiating invasive ventilation was greater than 2.5 billion Canadian dollars. MeaningThe preferred threshold to initiate invasive ventilation in hypoxemic respiratory failure is uncertain and further study would be valuable to society. Social media summaryWhen should we intubate and start invasive ventilation for people with hypoxemic respiratory failure? Our health economic evaluation shows that the preferred threshold is uncertain, but that a clinical trial to determine such a threshold would be immensely valuable to patients and society