Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

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> 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 is 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 non-invasive measurement, representative of disease severity and provides greater statistical power.

Original publication

DOI

10.1038/s41467-023-42205-6

Type

Journal

Nature Communications

Publication Date

01/12/2023

Volume

14