The prognostic value of chest X-ray in patients with COVID-19 on admission and when starting CPAP

Abstract

The objective was to explore if chest X-ray severity, assessed using a validated scoring system, predicts patient outcome on admission and when starting continuous positive pressure ventilation (CPAP) for COVID-19. The study was a retrospective case-controlled study. There were 163 patients with COVID-19 deemed candidates for CPAP on admission, including 58 who subsequently required CPAP. On admission, we measured the proportion of patients meeting a composite 'negative' outcome of requiring CPAP, intubation or dying versus successful ward-based care. For those escalated to CPAP, 'negative' outcomes were intubation or death versus successful de-escalation of respiratory support. Our results were stratified into tertiles, those with 'moderate' or 'severe' X-rays on admission had significantly higher odds of negative outcome versus 'mild' (odds ratio (OR) 2.32; 95% confidence interval (CI) 1.121-4.803; p=0.023; and OR 3.600; 95% CI 1.681-7.708; p=0.001, respectively). This could not be demonstrated in those commencing CPAP (OR 0.976; 95% CI 0.754-1.264; p=0.856). We outline a scoring system to stratify X-rays by severity and directly link this to prognosis. However, we were unable to demonstrate this association in the patients commencing CPAP.