A Retrospective Analysis of Thrombosis and COVID-19 Mortality in Rural Midwestern Population

Background COVID-19 disease has caused a major global impact on health and mortality. This infection may predispose patients to thrombotic disease, caused by excessive inflammation, endothelial dysfunction, platelet activation, and stasis. In this study, we compared mortality rates in patients admitted to the hospital with the diagnosis of COVID-19, who also had the additional diagnosis of thrombosis with those who did not have thrombosis as an additional diagnosis. Methods This retrospective observational study compared mortality rates in patients admitted to the hospital with the diagnosis of COVID-19, with and without thrombosis, as well as those patients admitted to the hospital with the diagnosis of thrombosis who did not have COVID-19. The diagnoses were verified using International Classification of Diseases Tenth Revision (ICD-10) codes, a standard among electronic medical records (EMR). The data were taken from the EMR at Freeman Health System in Joplin and Neosho, Missouri, from April 2020 to December 2021. This patient population is representative of not only Southwest Missouri but also the four-state area, including Oklahoma, Arkansas, and Kansas. The ICD-10 codes were used to separate the patient population into three main groups as follows: patients diagnosed with COVID-19 without thrombosis, patients diagnosed with thrombosis without COVID-19, and patients diagnosed with both COVID-19 and thrombosis. These three categories were then subdivided by age and biological sex. Sample proportions were completed using Wald's method, and the two-sample proportion summary hypothesis test with confidence intervals was used for the proportion difference. Results A total of 3,094 patients were included in the study population. Excluded from the study were patients who were previously admitted to a hospital for COVID-19 and duplicate admissions. The mortality rate was highest (0.4714) in patients concurrently diagnosed with COVID-19 and thrombosis (Population 1 {P1}), followed by patients diagnosed with COVID-19 without thrombosis (Population 2 {P2}, 0.1187). Patients diagnosed with thrombosis without COVID-19 (Population 3 {P3}, 0.1216) had the lowest mortality. Two sample proportion hypothesis tests determined confidence intervals (CI) for mortality risk comparing P3 to P1 (95% CI: 0.2888-0.4108, p<0.0001) and P2 to P1 (95% CI: 0.2919-0.4135, p<0.0001). Discussion In this rural, Midwestern population, patients admitted to the hospital with the diagnosis of COVID-19 and thrombosis had significantly increased mortality rates compared to patients admitted with the diagnosis of COVID-19 or thrombosis alone. Conclusion The data from this study indicated that individuals diagnosed with both COVID-19 and thrombosis had a higher likelihood of mortality compared to those diagnosed with COVID-19 without thrombosis and those diagnosed with thrombosis without COVID-19. This information could assist physicians in determining treatment plans for patients diagnosed with COVID-19 and a secondary complication of thrombosis.