Clinical characteristics and predictors of hospitalization among 7,108 ambulatory patients with positive RT-PCR for SARS-CoV-2 during the acute pandemic period

Daniela Simian, Maripaz Martínez, Jorge Dreyse, May Chomali, Marcelo Retamal, Gonzalo Labarca

To describe baseline characteristics of outpatients with a positive RT-PCR for SARS-CoV-2 and to define whether "red flags" (new-onset fever, dyspnea, and chest pain) can predict clinical worsening during the isolation period. This was an epidemiological, observational, descriptive study. Between March and September of 2020, all outpatients who tested positive for SARS-CoV-2 at a tertiary medical center located in Santiago de Chile were included. Demographic variables, comorbidities, red flags, and other symptoms were compiled using follow-up surveys at specific time points. The risk of clinical worsening (hospitalization) and adjusted hazard ratios (HRs) were calculated. A total of 7,108 patients were included. The median age was 38 years (range, 0-101), and 52% were men. At baseline, 77% of the patients reported having characteristic symptoms of SARS-CoV-2 infection. The most prevalent onset symptoms were headache (53%), myalgia (47%), and fever (33%). According to the follow-up surveys, the incidence of symptoms decreased during the isolation period; however, 28% of the patients still presented with symptoms on day 14. The risk of hospitalization for patients with new-onset fever and dyspnea during the follow-up period was HR = 7.43 (95% CI, 3.85-14.3, p<0.01) and HR = 5.27 (95% CI, 1.52-18.30; p < 0.01 for both), respectively. New-onset chest pain showed no association with clinical worsening. In this sample of outpatients with a recent diagnosis of SARS-CoV-2 infection, a survey-based monitoring of symptoms was useful to identify those at risk of clinical worsening. New-onset fever and dyspnea during the isolation period were considered as red flags associated with clinical worsening and warrants prompt medical evaluation.