Authors' reply to: Comment to better understanding of the study "Clinical characteristics and prognostic factors in COVID-19 patients aged ≥80 years".

Dear Editor,

We are delighted by the interest in our research by Dr. Arumalla and Dr. Patil, and we welcome the opportunity to clarify our work better. In our manuscript, as the former researchers noticed, the term “severe dementia” was not defined in the methods section. Actually, given the wide clinical spectrum of patients with cognitive disorders, we used this comprehensive formula in the paper. The term “severe dementia” in our manuscript referred to patients with a need for continuous assistance for personal care, reduced awareness of their surroundings and clinical conditions, reduced daily‐life physical abilities and eventually swallowing, and reduced capacity to communicate. Dementia diagnosis and severity were assessed by reviewing clinical records and discharge diagnosis, based on the codes defined by “International Classification of Disease, tenth revision” (ICD‐10 CM).

Concerning the relevance of our findings on the relationship between dementia and poor prognosis, we agree that as our sample is very small our study cannot draw irrefutable conclusions. Indeed, we already underlined this concern in the study limitations section of the paper. However, recently published data, as well as the clinical experience gained in the management of patients with COVID‐19, confirmed that medical assistance to patients with COVID‐19 and dementia is very challenging, and the prognosis could be very poor. Cipriani and Fiorino found that up to 12% of all patients that died from COVID‐19 had dementia. Similarly, Yao et al. found that among the 36 patients evaluated with COVID‐19 and dementia, mortality was as high as 62%.

Concerning our findings about increasing age and mortality, our data suggested that considering only patients ≥80 years, the increasing age did not represent by itself a risk factor for poor outcome. This was confirmed by Italian population data, and similar findings were reported by the US Center for Disease Control and Prevention, as the COVID‐19 mortality of patients aged 75–84 years old was almost similar or slightly higher than mortality rate at ≥85 years.

In our analysis, we attempted to correct our conclusions for potential confounders and comorbidities. Indeed, we found that comorbidities were similarly distributed in deceased compared with patients who survived, whereas dementia emerged as independently predictive of poor outcome. Moreover, as previously demonstrated, the multivariate analysis of small cohorts very often yields similar conclusions if repeated in greater populations.

To date, considering the very poor data available for very old patients with COVID‐19, we did our best to contribute to the knowledge about the peculiar aspects of the disease in this frailer population.

Disclosure statement

The authors declare no conflict of interest.