Clinical characteristics, risk factors and complications of COVID-19 among critically ill older adults - A case control study

Background: The older population is often disproportionately and adversely affected during humanitarian emergencies, as has also been seen during the COVID-19 pandemic. Data regarding COVID-19 in older adults is usually over-generalized and does not delve into details of the clinical characteristics in them. This study was conducted to analyze clinical and laboratory characteristics, risk factors, and complications of COVID-19 between older adults who survived and those who did not. Methods: We conducted a case-control study among older adults(age> 60 years) admitted to the Intensive Care Unit(ICU) during the COVID-19 pandemic. The non-survivors(cases) were matched with age and sex-matched survivors (control) in a ratio of 1: 3. The data regarding socio-demographics, clinical characteristics, complications, treatment, laboratory data, and outcomes were analyzed. Results: The most common signs and symptoms observed were fever (cases vs controls)(68.92 vs. 68.8%), followed by shortness of breath (62.2% Vs. 52.2%), and cough(47.3% Vs. 60.2%). Our analysis found no association between the presence of any of the comorbidities and mortality. At admission, laboratory markers such as LDH(Lactate Dehydrogenase), WBC(White Blood Count), creatinine, CRP(C-Reactive Protein), D-dimer, ferritin, and IL-6 were found to be significantly higher among the cases than among the controls. Complications such as the development of seizure, bacteremia, acute renal injury, respiratory failure, and septic shock were seen to have a significant association with non-survivors. Conclusions: Hypoxia, tachycardia, and tachypnoea at presentation were associated with higher mortality. The older adults in this study mostly presented with the typical clinical features of COVID-19 pneumonia. The presence of comorbid-illnesses among them did not affect mortality. Higher death was seen among those with higher levels of CRP, LDH, D-dimer, and ferritin; and with lower lymphocyte counts.