Abstract
Background: Safe, effective, and easily implementable treatments that reduce the progression of respiratory failure in COVID-19 are urgently needed. Despite the increased adoption of prone positioning during the pandemic, the effectiveness of this technique on progression of respiratory failure among nonintubated patients is unclear. Research Question: What is the effectiveness of smartphone-guided self-prone positioning recommendations and instructions compared with usual care in reducing progression of respiratory failure among nonintubated patients with COVID-19? Study Design and Methods: Awake Prone Position for Early Hypoxemia in COVID-19 (APPEX-19) is a multicenter randomized clinical trial that randomized nonintubated adults with COVID-19 on < 6 L/min of supplemental oxygen to receive a smartphone-guided self-prone positioning intervention or usual care. The primary outcome was the composite of respiratory deterioration (an increase in supplemental oxygen requirement) or ICU transfer. Using a Bayesian statistical approach, the posterior probability of superiority within each treatment arm (superiority threshold 95%) was calculated. Results: The trial was stopped early for slow enrollment. A total of 293 participants were included in the modified intention-to-treat analysis (159 self-prone positioning intervention and 134 usual care). Among participants who self-reported body positioning (n = 139 [70 intervention, 69 usual care]), 71.4% in the intervention arm and 59.4% in the usual care arm attempted prone positioning. Thirty-one participants (posterior mean, 24.7%; 95% credible interval, 18.6-31.4) receiving usual care and 32 participants (posterior mean, 22.1%; 95% credible interval, 16.6-28.1) receiving the self-prone positioning intervention experienced the primary outcome; the posterior probability of superiority for the self-prone positioning intervention was 72.1%, less than the 95% threshold for superiority. Adverse events occurred in 26.9% of participants in the usual care arm and in 11.9% of participants in the intervention arm. Interpretation: Among nonintubated patients with COVID-19, smartphone-guided self-prone positioning recommendations and instructions did not promote strong adherence to prone positioning. Clinical Trial Registration: ClinicalTrials.gov; No.: NCT04344587; URL: www.clinicaltrials.gov.