Determinants of 1-Year Adverse Event Requiring Re-Hospitalization in COVID-19 Oldest Old Survivors.

The incidence of "Long COVID" syndrome appears to be increasing, particularly in the geriatric population. At present, there are few data regarding the relationship between long COVID and the risk of re-hospitalization in the oldest old survivors. Patients older than 80 years consecutively hospitalized for COVID-19 in our tertiary care hospital were enrolled and followed after discharge in a 12-month ambulatory program. A comprehensive geriatric assessment (CGA), including functional capabilities and physical and cognitive performances, was performed at 6-month follow-up. Frailty degree was assessed using a 30-item frailty index. The re-hospitalization rate was assessed at 12-month follow-up through a computerized archive and phone interviews. Out of 100 patients discharged after hospitalization for COVID-19 (mean [SD] age 85 [4.0] years), 24 reported serious adverse events requiring re-hospitalization within 12 months. The most frequent causes of re-hospitalization were acute heart failure (HF), pneumonia and bone fracture (15.3% each). By multivariate logistic analysis, after adjustment for potential confounders, history of chronic HF [aOR: 3.00 (CI 95%: 1.10-8.16), p = 0.031] or chronic renal failure [aOR: 3.83 (CI 95%: 1.09-13.43), p = 0.036], the burden of comorbidity [(CIRSc) aOR: 1.95 (CI 95%: 1.28-2.97), p = 0.002] and frailty [aOR: 7.77 (CI 95%: 2.13-28.27), p = 0.002] resulted as independent predictors of re-hospitalization. One-fourth of the oldest old patients previously hospitalized for COVID-19 suffered from adverse events requiring re-hospitalization, two-thirds of them within three months after discharge. Frailty, the burden of comorbidity, history of chronic HF or chronic renal failure, but not COVID-19 disease severity, independently predicted re-hospitalization.