Assessing the Burden of Thromboembolic Complications in Outpatient COVID-19 Cases: A Focused Study on Patients Followed in Primary Care.

Background: Thromboembolic complications are frequently observed in patients with COVID-19 infection, particularly among those admitted to the intensive care unit (ICU). Moreover, COVID-19 infections today are mostly characterized by mild symptoms and are managed primarily in primary care settings, resulting in limited literature data on thromboembolic complications in this patient group. This study aims to investigate thrombotic event risks and associated factors in the outpatient population. Methods: All outpatient COVID-19 cases managed at two family health centers in Istanbul between June 2020 and December 2021 were retrospectively reviewed. Patients were contacted and informed about the study. Sociodemographic and clinical data were obtained from family health center records, and information on thrombotic events was extracted from hospital discharge summaries. Fisher's exact test and logistic regression were used for analysis. Results: A total of 961 patients were included in the study, of whom, 519 (54%) were female and 442 (46%) were male. The mean age was 41 years (range: 18-97). Thromboembolic events occurred in 4 patients (0.42%) within the first 6 months following COVID-19 infection. Logistic regression analysis identified the use of antacid medications (p=0.01) and the presence of hematological disorders (p=0.03) as significant risk factors. Conclusion: Thromboembolic events may occur even in mild-to-moderate outpatient COVID-19 cases within six months following the infection. Risk assessments focusing on comorbidities and medication use should be performed during outpatient follow-up. Due to the small number of thromboembolic events in this study, the findings should be considered preliminary and interpreted with caution. Trial Registration: ClinicalTrials.gov identifier: NCT06695377.