Systematic review and meta-analysis of the characteristics and outcomes of readmitted COVID-19 survivors.

The objective of the present study is to investigate the incidence, characteristics and outcomes of patients who were readmitted to hospital emergency departments or required re-hospitalisation following an index hospitalisation with a diagnosis of COVID-19. A systematic review of PubMed, EMBASE and pre-print websites was conducted between 1 January and 31 December 2020. Studies reporting on the incidence, characteristics and outcomes of patients with COVID-19 who represent or require hospital admission were included. Two authors independently performed study selection and data extraction. Study quality was assessed with the Newcastle-Ottawa Scale. Discrepancies were resolved by consensus or through an independent third reviewer. Data were synthesised according to the Preferred Reporting Items for Systematic Reviews guidelines. Six studies reporting on 547 readmitted patients were included. The overall incidence was 4.4%, most common in males (57.2%), and due to respiratory distress or prolonged COVID-19. Readmitted patients had a shorter initial hospital length of stay (LOS) compared with those with a single hospitalisation (8.1 ± 10.6 vs 13.9 ± 10.2 days). The mean time to readmission was 7.6 ± 6.0 days; the mean LOS on re-hospitalisation was 6.3 ± 5.6 days. Hypertension (odds ratio (OR) = 2.08; 95% confidence interval (CI) 1.69-2.55; P < 0.001; I = 0%), diabetes mellitus (OR = 1.77; 95% CI 1.38-2.27; P < 0.001; I = 0%) and chronic renal failure (OR = 2.37; 95% CI 1.09-5.14; P < 0.001; I = 0%) were more common in these patients. Intensive care admission rates were similar between the two groups; 12.8% (22/172) of readmitted patients died. In summary, readmitted patients following an index hospitalisation for COVID-19 were more commonly males with multiple comorbidities. Shorter initial hospital LOS and unresolved primary illness may have contributed to readmission.