Nonadherence in outpatient thrombosis prophylaxis with low molecular weight heparins after major orthopaedic surgery

Background: According to some current guidelines, extended thromboprophylaxis after hip and knee arthroplasties is recommended. Outpatient prophylaxis with low molecular weight heparins (LMWH) is an important part of this prophylaxis, although the rates of adherence to these regimens is not known. Questions/purposes: We determined (1) the degree of nonadherence (NA) of patients with LMWH outpatient prophylaxis, and (2) whether specific independent factors explain NA. Methods: NA was determined by syringe count and by indirect and direct questions to patients. We defined six different NA indicators. To identify factors explaining LMWH NA, we used three different logistic regression models. R…