Early Treatment with Hydroxychloroquine Improves Clinical Outcomes and Reduces Hospital Admissions in COVID-19 Associated Pneumonia

Background: Hydroxychloroquine (HCQ) has been used against SARS-CoV-2, but large non randomized studies failed to show any clinical benefit. However, in these studies the drug was started in the hospital setting, a significant time after the onset of symptoms. Aim of the Study: to verify if HCQ, given early after the onset of symptoms and in the outpatient setting, can reduce hospital admissions and improve clinical outcomes of COVID-19 Methods: We performed a retrospective study on 824 patients with COVID-19 pneumonia in the Bergamo province (Lombardy, Italy). Patients were divided in 2 cohorts: the first included 354 outpatients attended by Primary Care Physicians (PCP), the second included 470 patients admitted to an Emergency Department (ED) during the same period. We compared rate of hospital admission and clinical outcomes in patients treated with HCQ within 6 days from the onset of symptoms, with all other patients. Clinical outcomes were evaluated at a 1-month time-point. Results: Patients who received early treatment with HCQ showed a lower rate of hospital admissions (p<0.0001), mechanical ventilation (p<0.0022) and need for oxygen supplementation at home (p=0.002) in the first cohort and improved survival in the second (p=0.03). Early treatment with HCQ was the only independent variable influencing all predefined outcomes on multivariate analysis. Conclusions: Treatment with HCQ, initiated within 6 days from the onset of COVID-19 may improve both clinical outcome and rate of hospital admissions.