Atypical disease presentations are common in older adults with COVID-19. The objective of this study was to determine the prevalence of atypical and typical symptoms in older adults with COVID-19 through progressive pandemic waves and the association of these symptoms with in-hospital mortality. This retrospective cohort study included consecutive adults aged over 65 years with confirmed COVID-19 infection who were admitted to seven hospitals in Toronto, Canada, from 1 March 2020 to 30 June 2021. The median age for the 1786 patients was 78.0 years and 847 (47.5%) were female. Atypical symptoms (as defined by geriatric syndromes) occurred in 1187 patients (66.5%), but rarely occurred in the absence of other symptoms (n = 106; 6.2%). The most common atypical symptoms were anorexia (n = 598; 33.5%), weakness (n = 519; 23.9%), and delirium (n = 449; 25.1%). Dyspnea (adjusted odds ratio [aOR] 2.05; 95% confidence interval [CI] 1.62–2.62), tachycardia (aOR 1.87; 95% CI 1.14–3.04), and delirium (aOR 1.52; 95% CI 1.18–1.96) were independently associated with in-hospital mortality. In a cohort of older adults hospitalized with COVID-19 infection, atypical presentations frequently overlapped with typical symptoms. Further research should be directed at understanding the cause and clinical significance of atypical presentations in older adults.
COVID-19 infection is associated with increased morbidity and mortality in older adults (Guan et al. 2020). Studies early in the pandemic revealed that older adults frequently did not have typical symptoms, such as cough, fever, or shortness of breath (Singhal et al. 2021). Atypical symptoms in older adults include geriatric syndromes, such as delirium, anorexia, or falls (Singhal et al. 2021). These presentations are nonspecific to COVID-19 (Hofman et al. 2017) and can occur with other diagnoses; as such, clinicians needed to increase their level of suspicion of COVID-19 infection in older adults. Atypical presentations in COVID-19 have been variably associated with mortality (Gan et al. 2020). However, the definition of atypical presentation differs by study and it is often mixed with nongeriatric syndromes, such as abdominal pain or headache (Gan et al. 2020). A geriatric-focused approach to the classification of COVID-19 symptoms would help better illustrate the spectrum of presentations.
As recurrent waves of the pandemic occurred across the world, new variants of COVID-19 emerged. Later variants, particularly the beta (B.1.351), gamma (P.1), and delta (B.1617.2) variants, were more virulent (Fisman and Tuite 2021) and presented with different symptoms (ZOE COVID Study 2021). In Ontario, Canada, wave 1 was predominantly caused by wild-type SARS-CoV-2 virus, while wave 2 was predominantly alpha variant (B.1.1.7), and wave 3 had increasing beta and gamma variants (Public Health Ontario 2021). It is unknown whether clinical presentation changed in older adults across these three waves.
Furthermore, despite systematic reviews of early studies of COVID-19 symptoms (Singhal et al. 2021), there is a lack of data looking at the way individuals with different comorbidities, place of residence, and frailty present. In particular, older age has been cited as the primary factor associated with atypical presentations of COVID-19, but it is unclear whether comorbidities and frailty also play a role.
Using a multicentre study of consecutively admitted older adults with COVID-19, the objectives of this study were to determine (i) the prevalence of each symptom and symptom category in older adults with COVID-19, (ii) the association of each symptom with in-hospital mortality, (iii) the change in symptoms with progressive waves of the pandemic, and (iv) whether clinical presentation differs by age, frailty, place of residence, and comorbidity.