Primary Upper Extremity Deep Venous Thrombosis and Comorbidity: A Population-Based Nationwide Study in Sweden

Abstract BackgroundThere have been few studies on primary upper extremity deep vein thrombosis (UEDVT) and the comorbidityis not very well known, in contrast to secondary UEDVT.MethodsWe conducted a nationwide, population-based case control study in Sweden using data from the Swedish National Patient Register (NPR).We examined comorbidityin 25 cases with a confirmed UEDVT with a control group (appendicitis) during the years 2001–2011 in patients over 18 years old. We defined comorbidityas the number of unique ICD codes ( International Statistical Classificationof Diseasesand Related Health Problems) and the total number of healthcare contacts.ResultsThe number of unique ICD codes was similar between cases and controls, although they differed regarding specific diagnoses. Patients with a UEDVT were more likely to later have a diagnosis related to blood-forming organs, the endocrine system, the nervous system, the circulatory system, and to the skin and musculoskeletal systems, compared with the controls.Diagnoses for symptoms from the brachial plexusand diagnoses referring to pain and discomfort of the upper extremity were more frequent in the cases. The major difference occurred in diagnoses involving the circulatory system, which were more frequent in the cases. The most important cases and controls were similar regarding diagnoses of malignancy. The cases had a significantly higher number of healthcare contacts.ConclusionThe type of comorbidityand the number of healthcare contacts differed between patients with a diagnosis of UEDVT, compared with those with appendicitis. There was no difference regarding malignancies, which implies that primary UEDVT is a benign disorder.