Association of consciousness impairment and mortality in people with COVID-19

Abstract

Background: To investigate the association between impairment of consciousness and risk of death in people with COVID-19.

Methods: In this multicentre retrospective study, we enrolled people with confirmed COVID-19 from 44 hospitals in Wuhan and Sichuan, China, between 18 January and 30 March 2020. We extracted demographics, clinical, laboratory data and consciousness level (as measured by the Glasgow Coma Scale (GCS) score) from medical records. We used Cox proportional hazards regression, structural equation modelling and survival time analysis to compare people with different progressions of impaired consciousness.

Results: We enrolled 1,143 people (average age 51.3 ± standard deviation 17.1-year-old; 50.3% males), of whom 76 died. Increased mortality risk was identified in people with GCS score between 9 and 14 (hazard ratio (HR) 46.76, p < .001) and below 9 (HR 65.86, p < .001). Pathway analysis suggested a significant direct association between consciousness level and death. Other factors, including age, oxygen saturation level and pH, had indirect associations with death mediated by GCS scores. People who developed impaired consciousness more rapidly either from symptoms onset (<10 days vs. 10-19 days, p = .025, <10 days vs. ≥20 days and 10-19 days vs. ≥20 days, <.001) or deterioration of oxygen saturation (≤2 days vs.>2 days, p = .028) had shorter survival times.

Conclusion: Altered consciousness and its progression had a direct link with death in COVID-19. Interactions with age, oxygen saturation level and pH suggest possible pathophysiology. Further work to confirm these findings explore prevention strategies and interventions to decrease mortality is warranted.

Keywords: Glasgow Coma Scale; death; outcomes; risk factors.