Hospital readmissions of discharged patients with COVID-19

Background. COVID-19 infection has led to an overwhelming effort by health institutions to meet the high demand for hospital admissions. Aim. To analyse the clinical variables associated with readmission of patients who had previously been discharged after admission for COVID-19. Design and methods. We studied a retrospective cohort of patients with laboratory-confirmed SARS-CoV-2 infection who were admitted and subsequently discharged alive. We then conducted a nested case-control study paired (1:1 ratio) by age, sex and period of admission. Results. Out of 1368 patients who were discharged during the study period, 61 patients (4.4%) were readmitted. Immunocompromised patients were at increased risk for readmission. There was also a trend towards a higher probability of readmission in hypertensive patients (p=0.07). Cases had had a shorter hospital stay and a higher prevalence of fever during the 48 hours prior to discharge. There were no significant differences in oxygen levels measured at admission and discharge by pulse oximetry intra-subject or between the groups. Neutrophil/lymphocyte ratio at hospital admission tended to be higher in cases than in controls (p=0.06). The motive for readmission in 10 patients (16.4%), was a thrombotic event in venous or arterial territory (p<0.001). Neither glucocorticoids nor anticoagulants prescribed at hospital discharge were associated with a lower readmission rate. Conclusions. The rate of readmission after discharge from hospital for COVID-19 was low. Immunocompromised patients and those presenting with fever during the 48 hours prior to discharge are at greater risk of readmission to hospital.