Clinical characteristics and treatment outcomes among the hospitalized elderly patients with COVID-19 during the late pandemic phase in central Taiwan.

Background: There is a lack of information regarding outcomes of elderly patients hospitalized with COVID-19 following the widespread use of COVID-19 vaccines and antiviral agents.

Methods: A retrospective study was conducted between January and August 2022, enrolling patients aged 65 years or older. Patients were categorized into two groups: 'old' (65-79 years) and 'oldest-old' (80 years or more). Multivariate regression was employed to identify independent prognostic factors for in-hospital mortality.

Results: A total of 797 patients were enrolled, including 428 old and 369 oldest-old patients. In each subgroup, 66.6 % and 59.6 % of patients received at least one dose of the COVID-19 vaccine, respectively. Approximately 40 % of the patients received oral antiviral agents either before or upon hospital admission. A greater percentage of the oldest-old patients received remdesivir (53.4 % versus 39.7 %, p < 0.001), dexamethasone (49.3 % versus 36.7 %, p < 0.001), and tocilizumab (10.0 % versus 6.8 %, p < 0.001) than old patients. The mortality rate was comparable between the two age subgroups (14 % versus 15.2 %). Independent predictors of in-hospital mortality included disease severity and comorbidities such as end-stage renal disease (ESRD), cirrhosis, solid tumours, and haematologic malignancies. Ageing was not correlated with increased in-hospital mortality across all comorbidity subgroups.

Conclusions: In the later stages of the pandemic, with widespread vaccination and advancements in COVID-19 treatments, outcomes for hospitalized elderly and oldest-old patients with COVID-19 have improved. The influence of age on in-hospital mortality has diminished, while comorbidities such as ESRD, cirrhosis, solid tumours, and hematologic malignancies have been associated with mortality.