Predicting severe outcomes in Covid-19 related illness using only patient demographics, comorbidities and symptoms

Ryan, Charles; Minc, Alexa; Caceres, Juan; Balsalobre, Alexandra; Dixit, Achal; Ng, Becky; Schmitzberger, Florian; Syed-Abdul, Shabbir; Fung, Christopher

OBJECTIVE: Development of a risk-stratification model to predict severe Covid-19 related illness, using only presenting symptoms, comorbidities and demographic data. MATERIALS AND METHODS: We performed a case-control study with cases being those with severe disease, defined as ICU admission, mechanical ventilation, death or discharge to hospice, and controls being those with non-severe disease. Predictor variables included patient demographics, symptoms and past medical history. Participants were 556 patients with laboratory confirmed Covid-19 and were included consecutively after presenting to the emergency department at a tertiary care center from March 1, 2020 to April 21, 2020 RESULTS: Most common symptoms included cough (82%), dyspnea (75%), and fever/chills (77%), with 96% reporting at least one of these. Multivariable logistic regression analysis found that increasing age (adjusted odds ratio [OR], 1.05; 95% confidence interval [CI], 1.03–1.06), dyspnea (OR, 2.56; 95% CI: 1.51–4.33), male sex (OR, 1.70; 95% CI: 1.10–2.64), immunocompromised status (OR, 2.22; 95% CI: 1.17–4.16) and CKD (OR, 1.76; 95% CI: 1.01–3.06) were significant predictors of severe Covid-19 infection. Hyperlipidemia was found to be negatively associated with severe disease (OR, 0.54; 95% CI: 0.33–0.90). A predictive equation based on these variables demonstrated fair ability to discriminate severe vs non-severe outcomes using only this historical information (AUC: 0.76). CONCLUSIONS: Severe Covid-19 illness can be predicted using data that could be obtained from a remote screening. With validation, this model could possibly be used for remote triage to prioritize evaluation based on susceptibility to severe disease while avoiding unnecessary waiting room exposure.