DOI: 10.5061/dryad.fqz612jxh
title: Clinical characteristics, risk factors and complications of COVID-19 among critically ill older adults – A case control study

description: 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-generalised and does not delve into details of the clinical
 characteristics in them. This study was conducted to analyse 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 &gt; 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 analysed. 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(Interleukin-6) were found to be significantly higher among the cases
 than among the controls. Complications such as 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.
description: A hospital-based case-control study was undertaken. Data was
 collected from the Intensive Care Unit(ICU) from December 2020 to
 September 2022. The sample size was calculated with a two-sided confidence
 level(1-α) of 95, 80% power, and with a ratio of controls to cases at 3:1.
 A sample size of 260 was calculated consisting of 195 controls and 65
 cases. A Case was defined as a COVID-19-positive individual older than 60
 years who, after being admitted or transferred to the ICU, did not
 survive, i.e., <em>non</em>-<em>survivor</em>. A
 Control was defined as a COVID-19-positive individual with age greater
 than 60 years who was admitted or transferred to the ICU, following which
 the patient recovered(survived) and was discharged alive from the
 hospital, i.e., <em>survivor</em>. Those patients who were
 admitted for post-COVID-19 complications or for COVID-19 unrelated medical
 conditions following discharge after initial treatment for COVID-19
 pneumonia were excluded. The cases (non-survivors) were recruited
 according to the inclusion and exclusion criteria mentioned above and were
 then matched with an age and sex-matched control (survivor) in a ratio of
 1: 3, respectively. The data regarding socio-demographics, clinical
 characteristics, complications, treatment, laboratory data, and outcomes
 were collected using a modified ISARIC form. The patient's identity
 was anonymized by assigning a code. The comorbidities and risk factors
 recorded in the study were chronic cardiac disease(including
 hypertension), chronic pulmonary disease(including asthma), chronic kidney
 disease, obesity, liver disease, asplenia, chronic neurological disorder,
 malignant neoplasm, chronic hematological disease, AIDS/HIV, diabetes
 mellitus, rheumatological disorder, dementia, tuberculosis, malnutrition,
 and smoking. Before the study's launch and data collection, approval
 was acquired from the Institutional Ethics Committee and the medical
 directors of the participating institutions. Data collection was done
 using Microsoft Excel. Data were analysed using the IBM SPSS Statistics
 for Windows, Version 25.0. Armonk, NY: IBM Corp. The
 data were expressed as mean and SD for continuous variables. Based on the
 type of distribution of data, a t-test or Mann-Whitney U test was applied.
 The categorical variables were analysed using Pearson's chi-square or
 Fisher's exact test based on the data distribution. 
description: Microsoft Excel, Word