Outcomes
We defined three outcomes for which we deemed that jointly would adequately inform about unfavorable develompents in COVID-19 outpatients. COVID-19-related hospitalization – hospitalization that followed within 45 days since the index COVID-19 diagnosis, with U07.1/U07.2 as the leading discharge diagnosis; or hospitalization that followed within 30 days since the index COVID-19 diagnosis and U07.1/U07.2 is listed among discharge diagnoses. 30-day all-cause hospitalization – hospitalization that follows within 30 days since the index COVID-19 diagnosis. COVID-19-related death – we considered that death was “related to” COVID-19 if meeting any of the following (i) COVID-19 (U07.1/U07.2) is listed as a cause of death; (ii) death occurred within 14 days since the index COVID-19 diagnosis, regardless of the declared cause; (iii) death occurred in hospital, where hospitalization was COVID-19 related hospitalization (as defined above).