Protocol for assessing and predicting acute respiratory decline in hospitalized patients.

This protocol aids both new and experienced researchers in designing retrospective clinical and translational studies of acute respiratory decline in hospitalized patients. This protocol addresses (1) the basics of respiratory failure and electronic health record research, (2) defining patient cohorts as "mild, progressive, or severe" instead of "ICU versus non-ICU", (3) adapting physiological indices, and (4) using biomarker trends. We apply these approaches to inflammatory biomarkers in COVID-19, but this protocol can be applied to any progressive respiratory failure study. For complete details on the use and execution of this protocol, please refer to Mueller et al. (2020).