Study participants

Patients were eligible for inclusion in PREVENT CLOT if they: (1) were 18 years of age or older, (2) had a planned operative or non-operative pelvis or acetabular fracture, or any operative extremity fracture proximal to the metatarsals or metacarpals, and (3) were at an increased risk of a blood clot from their orthopaedic injury and would receive a prophylactic blood thinner regimen per standard of care. Patients were excluded if they: (1) presented to the hospital more than 48 hours from injury, (2) had received more than two doses of venous thromboembolism (VTE) prophylaxis, (3) were on long term blood thinners, (4) had a VTE within the last 6 months, (5) had an allergy to the study medications, (6) had an underlying chronic clotting disorder, (7) had end-stage renal disease, (8) were pregnant or lactating, (9) did not speak either English or Spanish, or (10) were a prisoner at the time of screening.

By virtue of the types of injuries studied, often resulting from high energy mechanisms such as motor vehicle crashes, high falls, and blast injuries, some eligible patients were unable to provide consent for the study due to associated traumatic brain injury or intubation status. Including these patients was integral to ensuring the generalisability of the research findings. However, in these situations, the research staff member sought consent from a legally authorised representative.

If the patient met the eligibility criteria, a member of the research staff would approach the eligible participants or their legally authorised representatives to discuss the study and request consent to participate. The research staff endeavoured to answer all questions posed by the eligible study participants and their caregivers to ensure an understanding of the protocol. After introducing the study and reviewing the consent form, the research staff member posed several questions to assess the participant’s (or representative’s) comprehension of the study, the responsibilities of participation, and alternatives to participation.