Clinical Characteristics and In-hospital Death of a Chilean COVID-19 Prospective Cohort

This is a prospective cohort study of adult inpatients at University of Chile Clinical Hospital, located in Santiago, Chile. We enrolled all patients aged over 18 years detected with COVID-19 admitted to the emergency department between March 1-June 11, 2020 through prospective identification using daily admission records. Briefly, COVID-19 diagnosis was made when patients had clinical findings of acute respiratory illness together with i) a positive result on reverse transcriptase chain reaction polymerase (RT-PCR) assay performed on a nasopharyngeal swab; and/or ii) chest computed tomography (CT) with typical findings of COVID-19 and absence of an alternative diagnosis. We intended to include all admitted patients during the first 100 days of the pandemic; therefore, no sample size calculation was performed. We excluded patients with length of stay less than 24 hours, nosocomial SARS-CoV-2 infection, and asymptomatic patients admitted for causes unrelated to SARS-CoV-2 infection regardless of their admission RT-PCR result.

All data were prospectively recorded for each included patient at admission and then daily until the end of the follow-up. Records were consulted by trained physicians, using a standardized data collection form, and then checked by a team of four physicians. Data discrepancy was agreed between the same clinicians.

Recorded data included demographic characteristics, comorbidities, disease onset time, associated symptoms, vital signs at the emergency department, laboratory test performed within 24 hours after admission, characteristics of the first chest CT, medication and supportive care provided, and length of stay at the hospital.

The use of antibiotics, antiviral therapy, corticosteroids, advanced oxygen delivery techniques, need for invasive mechanical ventilation (IMV), awake and ventilated prone position, use of vasopressor drugs, and need for renal replacement therapy (RRT) were explicitly recorded. Clinical management and use of these therapies were based on national recommendations from scientific societies and local protocols. Outcome collection and assignment are explained below.

Laboratory confirmation of SARS-CoV-2 infection was made using RT-PCR of nasopharyngeal swabs. All laboratory, microbiologic, and radiologic assessments were performed at the discretion of the treating physicians who were encouraged to follow local clinical guidelines. Film-array on the nasopharyngeal swab was performed for viral co-infection assessment, and urinary antigens. (pneumococcal and legionella) and blood cultures were performed for bacterial co-infection assessment. Chest radiographs and CT were also performed for all inpatients by experienced radiologists and classified as COVID-19-unrelated, typical or atypical pattern, and unspecified.

Inclusion criteria

• Patients over 18 years
• Diagnosis of COVID-19 defined by clinical findings of acute respiratory illness (as per WHO guidelines) together with i) a positive result on reverse transcriptase chain reaction polymerase (RT-PCR) assay performed on a nasopharyngeal swab; and/or ii) chest computed tomography (CT) with typical findings of COVID-19 and absence of an alternative diagnosis

Exclusion criteria

• Length of hospital stay less than 24 hours
• Nosocomial SARS-CoV-2 infection
• Asymptomatic patients admitted for causes not related to coronavirus infection regardless their admission RT-PCR result