CLINICAL CHARACTERISTICS AND RISK FACTORS FOR ADVERSE OUTCOMES IN ELDERLY PATIENTS WITH SEVERE COVID-19.

OBJECTIVE: To identify key clinical, laboratory, and imaging predictors of adverse outcomes in elderly patients aged 60-74 years with COVID-19. MATERIALS AND METHODS: A comprehensive retrospective analysis was conducted among elderly patients diagnosed with COVID-19. The participants were divided into two groups: survivors (n=50) and non-survivors (n=140). The study was conducted from May to October 2021 at the City Clinical Infectious Diseases Hospital No.3 in Astana, Kazakhstan. Statistical analysis was performed using non-parametric methods, including the Mann-Whitney U test. RESULTS: Elderly patients aged 60-74 years accounted for 48% of all in-hospital deaths during the study period (140 of 292 deaths). Adverse outcomes were strongly associated with the development of a systemic inflammatory response. In the non-survivor group, critical median values were identified for C-reactive protein (CRP) - 97.9 mg/L, interleukin-6 (IL-6) - 38.15 pg/mL, and the lung involvement on CT imaging - 45.0% (IQR: 30.0-60.0%). Concomitant chronic bronchopulmonary pathology was also more frequent in the non-survivor group than in the survivor group (31% vs. 8%). Statistically significant differences between non-survivors and survivors were found for CRP levels (p=0.001), IL-6 levels (p=0.024), CT -assessed lung involvement (p=0.032), and chronic bronchopulmonary pathology (p=0.001). CONCLUSION: This study identified critical markers of clinical decompensation in COVID-19 patients aged 60-74 years: lung involvement≥ 45% on CT imaging (CT-2/CT-3), IL-6 >40 pg/mL, and CRP >100 mg/L. Concomitant bronchopulmonary pathology was significantly more frequent among non-survivors than among survivors (31% vs. 8%) and was associated with an adverse outcome. These findings support the need for early targeted therapy when the specified threshold values are reached.