Clinical decision support tool for diagnosis of COVID-19 in hospitals

Abstract

Background: The coronavirus infectious disease 19 (COVID-19) pandemic has resulted in significant morbidities, severe acute respiratory failures and subsequently emergency departments' (EDs) overcrowding in a context of insufficient laboratory testing capacities. The development of decision support tools for real-time clinical diagnosis of COVID-19 is of prime importance to assist patients' triage and allocate resources for patients at risk.

Methods and principal findings: From March 2 to June 15, 2020, clinical patterns of COVID-19 suspected patients at admission to the EDs of Liège University Hospital, consisting in the recording of eleven symptoms (i.e. dyspnoea, chest pain, rhinorrhoea, sore throat, dry cough, wet cough, diarrhoea, headache, myalgia, fever and anosmia) plus age and gender, were investigated during the first COVID-19 pandemic wave. Indeed, 573 SARS-CoV-2 cases confirmed by qRT-PCR before mid-June 2020, and 1579 suspected cases that were subsequently determined to be qRT-PCR negative for the detection of SARS-CoV-2 were enrolled in this study. Using multivariate binary logistic regression, two most relevant symptoms of COVID-19 were identified in addition of the age of the patient, i.e. fever (odds ratio [OR] = 3.66; 95% CI: 2.97-4.50), dry cough (OR = 1.71; 95% CI: 1.39-2.12), and patients older than 56.5 y (OR = 2.07; 95% CI: 1.67-2.58). Two additional symptoms (chest pain and sore throat) appeared significantly less associated to the confirmed COVID-19 cases with the same OR = 0.73 (95% CI: 0.56-0.94). An overall pondered (by OR) score (OPS) was calculated using all significant predictors. A receiver operating characteristic (ROC) curve was generated and the area under the ROC curve was 0.71 (95% CI: 0.68-0.73) rendering the use of the OPS to discriminate COVID-19 confirmed and unconfirmed patients. The main predictors were confirmed using both sensitivity analysis and classification tree analysis. Interestingly, a significant negative correlation was observed between the OPS and the cycle threshold (Ct values) of the qRT-PCR.

Conclusion and main significance: The proposed approach allows for the use of an interactive and adaptive clinical decision support tool. Using the clinical algorithm developed, a web-based user-interface was created to help nurses and clinicians from EDs with the triage of patients during the second COVID-19 wave.

Fig 1. Number of patients suspected to be infected with SARS-CoV-2 directed to the triage centers located close to the emerging departments of the Liège University Hospital (N = 4,489) in function of weeks as well as those that were tested by qRT-PCR and included in the present study (N = 2,152).

Patients suspected to be infected with SARS-CoV-2 (black circles) and patients tested by qRT-PCR and included in the study (white circles).

Fig 2. Receiver operating characteristic curve of the overall pondered score of COVID-19.

Points are the observed values; the solid curve in black and its 95% confidence interval (broken curves in black) was fitted according to a binormal distribution. Area under curve = 0.71 (95% CI: 0.68–0.73) with standard error = 0.012.

Fig 3. The evolving of the Overall Pondered Score (OPS) in function of the period of the first COVID-19 pandemic wave.

Fig 4. Classification decision tree for clinically suspected COVID-19 cases at the Liège University Hospital (N = 2,152).

(1) and (0), presence and absence of the symptom; Class, in blue or red, the number of confirmed or unconfirmed patients to SARS-CoV-2, respectively.