@article{Swets_M-2023_158681,
title = {Evaluation of pragmatic oxygenation measurement as a proxy for Covid-19 severity},
author = {Swets, M. and Kerr, S. and Scott-Brown, J. and Brown, A. and Gupta, R. and Millar, J. and Spata, E. and McCurrach, F. and Bretherick, A. and Docherty, A. and Harrison, D. and Rowan, K. and Young, N. and Groeneveld, G. and Dunning, J. and Nguyen-Van-Tam, J. and Openshaw, P. and Horby, P. and Harrison, E. and Staplin, N. and Semple, M. and Lone, N. and Baillie, J.},
month = {nov},
year = {2023},
abstract = {Choosing optimal outcome measures maximizes statistical power, accelerates discovery and improves reliability in early-phase trials. We devised and evaluated a modification to a pragmatic measure of oxygenation function, the 𝑆/𝐹 ratio. Because of the ceiling effect in oxyhaemoglobin saturation, 𝑆/𝐹 ratio ceases to reflect pulmonary oxygenation function at high 𝑆𝑝𝑂2 values. We found that the correlation of 𝑆/𝐹 with the reference standard (𝑃𝑎𝑂2/𝐹𝐼𝑂2 ratio) improves substantially when excluding 𝑆𝑝𝑂2 &gt; 0.94 and refer to this measure as 𝑆/𝐹94. Using observational data from 39,765 hospitalised COVID-19 patients, we demonstrate that 𝑆/𝐹94 isn predictive of mortality, and compare the sample sizes required for trials using four different outcome measures. We show that a significant difference in outcome could be detected with the smallest sample size using 𝑆/𝐹94. We demonstrate that 𝑆/𝐹94 is an effective intermediate outcome measure in COVID-19. It is a noninvasive measurement, representative of disease severity and provides greater statistical power.},
volume = {14},
journal = {Nature Communications},
publisher = {Springer Nature},
url = {https://doi.org/10.1038/s41467-023-42205-6},
}
