Clinical characteristics and outcome of Covid-19 illness and predictors of in-hospital mortality in Saudi Arabia

Background: Patients' race and ethnicity may play a role in mortality from Covid-19. Studies in China, the US, and Europe have been conducted on the predictors of Covid-19 mortality, yet in the EMR countries, such studies are scarce. Therefore, we aimed to describe the hospitalization rate, ICU-admission, and in-hospital mortality of Covid-19 and predictors of in-hospital mortality in Saudi Arabia. Methods: E-medical records were examined for all Covid-19 patients diagnosed in five tertiary hospitals affiliated with the Saudi-National Guard-Health Affairs during March 21, 2020, and September 12, 2021, based on a positive SARS-CoV-2 RT-PCR test, (n = 35,284). Data were collected on patients' characteristics, comorbidities, laboratory findings, hospitalization, ICU admission, and in-hospital and overall mortality. Logestic regressions were used to identify the independent predictors of in-hospital mortality. The best laboratory parameters cut-off values to predict in-hospital mortality were identified using the area under the receiver operating characteristic curve (AUC). Significance was considered at p < 0.05. Results: Of all 35,284 Covid-19 patients, 81.8% were adults and 21.7% were hospitalized. Compared to non-hospitalized patients, hospitalized patients were more of female gender (52.1% versus 47.3%, p < 0.001) and had higher mean age (p < 0.001), higher mean BMI (p < 0.001), and higher rates of: diabetes (p < 0.001), hypertension (p < 0.001), ischemic heart disease (p < 0.001), cancer (p < 0.001), COPD (p < 0.001) and asthma (p = 0.011). The study showed 3.1% overall case-fatality, 20.3% ICU admission rate, and 9.7% in-hospital mortality. Predictors of in-hospital mortality among adult patients were; patients' age >= 70 years (OR = 6.93, 95% CI 1.94-24.79), ischemic heart disease (OR = 1.80, 95% CI 1.05-3.09), ICU admission (OR = 24.38, 95% CI 15.64-38.01), abnormal C-reactive protein "CRP " (OR = 1.85, 95% CI 1.08-3.16), abnormal D-dimer (OR = 1.96, 95% CI 1.15-3.36), lymphopenia (OR = 2.76, 95% CI 2.03-3.3.76), high neutrophil count (OR = 2.10, 95% CI 1.54-2.87), and abnormal procalcitonin (OR = 3.33, 95% CI 1.88-5.90). The best laboratory parameters cut-off values to predict in-hospital mortality were CRP > 72.25 mg/L (AUC = 0.64), d-dimer > 1125 mu g/L (AUC = 0.75), neutrophils count > 5,745 x 10 boolean AND 9/L (AUC = 0.70), lymphocytic count < 1.10 x 10 boolean AND 9/L (AUC = 0.72), and procalcitonin > 0.18 ng/mL (AUC = 0.76). Conclusions: Rates of hospitalization, ICU-admission, in-hospital mortality and overall case fatality were nearly comparable to the rates in western countries. Early interventions are necessary for high-risk Covid-19 patients, especially elderly patients and those with cardiac diseases.