Mortality and Predictors of Mortality Among COVID-19 Patients in Kiambu County, Kenya

SARS-CoV-2 continues to circulate with new variants of uncertain transmissibility and virulence arising over time and resulting in varying morbidity and mortality between and within countries. This study aimed to identify the predictors of mortality among hospitalized COVID-19 patients across the first five waves of the pandemic. We conducted a retrospective cohort study at Tigoni Level 4 Hospital in Kenya. The study included patients admitted between June 2020 to August 2022 who tested positive for SARS-CoV-2. Sociodemographic and clinical data were abstracted from patient records at the time of admission and throughout their hospital stay. We employed Cox proportional hazard regression analysis to estimate the time to event (discharge or death) and identify predictors of mortality. Both time-varying and non-time-varying covariates were included in the models. A total of 1985 patients were admitted, of whom 557 (28%) died. The median hospital stay was 4 (1.0-8.0) days and 9 (5.0-13.0) days for patients who died and those who were discharged alive, respectively. Compared to patients admitted during wave 1, those admitted during the subsequent waves had high risk of death estimated at adjusted HR: 1.66 (95% CI 1.2, 2.54), 5.17 (95% CI 3.55, 7.53), 2.62 (95% CI 1.87, 3.67), and 2.17 (95% CI 1.51, 3.11) for waves 2, 3, 4, and 5, respectively. A proportion of patients presented with persistent chest pain, cough, and hypoxia and continued oxygen therapy for more than two months. In addition, patients who had persistent fever, hypoxia, cough, and fatigue had a significant mortality risk (adjusted HR: 3.00; 95% CI: 1.81-4.98; HR: 1.97; 95% CI: 1.73-2.26; HR: 1.47; 95% CI: 1.24-1.75; HR: 1.64; 95% CI: 1.05-2.54). Conversely, patients who had low oxygen saturation and received oxygen at admission had a 76% (HR: 0.24; 95% CI: 0.13-0.42) reduction in mortality risk and in addition patients whose treatment was altered had a 49% reduction in mortality risk (HR: 0.51; CI: 0.45-0.58). Our study highlights the benefits of oxygen therapy on the outcome of COVID-19 patients and justifies the need to increase investments in oxygen especially in low-and-middle-income countries. It also confirms the need to analyze the pandemic by the different waves.