Plain English Summary
Background and study aims
Venous thromboembolism (VTE) is a condition in which a blood clot forms most often in the deep veins of the leg, groin or arm (known as deep vein thrombosis, DVT) and travels in the circulation, lodging in the lungs (known as pulmonary embolism, PE). Together, DVT and PE are known as VTE - a dangerous, potentially deadly medical condition. VTE is a serious complication with a high incidence during and after hospitalization, and it is also an important factor in deaths before and after surgery and unexpected deaths in hospitals. In patients who undergo hip fracture surgery, it is recommended that the duration of drug prevention be at least 10 days and extendable to 11–35 days. Several studies have shown that extended prophylaxis substantially reduces the risk of VTE and recommend a longer prophylaxis duration in all patients undergoing hip fracture surgery. This study compares the use of aspirin and rivaroxaban for the prevention of blood clots following hip surgery.
Who can participate?
Patients with hip fracture who require surgery.
What does the study involve?
All patients were given enoxaparin after the operation and returned to a routine dose the next day until postoperative day five. The patients in the aspirin group received an additional 16 days of thromboprophylaxis with 100 mg of aspirin once daily. The rivaroxaban group was assigned to receive an additional 16 days of thromboprophylaxis with 10 mg of oral rivaroxaban once daily.
What are the possible benefits and risks of participating?
Where is the study run from?
Chengdu Fifth People’s Hospital, Chengdu, China
When is the study starting and how long is it expected to run for?
November 2011 to March 2018
Who is funding the study?
Who is the main contact?
Dr Qiang Huang
Comparison of the efficacy and safety of aspirin and rivaroxaban following enoxaparin treatment for prevention of VTE after hip fracture surgery
Aspirin may have equal efficiency and safety with the direct oral anticoagulant rivaroxaban for the prevention of venous thromboembolism after hip fracture surgery
Approved 16/09/2011, Medical Ethics Committee of Chengdu Fifth People’s Hospital (No. 56 Wanchun East Road, Wenjiang District, Chengdu, Sichuan Province, China; 028-82783867; firstname.lastname@example.org), ref: 2019075101
Interventional pseudorandomised trial
Primary study design
Secondary study design
Cluster randomised trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet.
Prevention of venous thromboembolism after hip fracture surgery
The patients were divided into the aspirin group and rivaroxaban group according to odd or even number of the end of the registration number. All patients were given enoxaparin subcutaneous injection after the operation and returned to a routine dose the next day until postoperative day 5. The patients in the aspirin group received an additional 16 days of thromboprophylaxis with 100 mg of aspirin once daily. The rivaroxaban group was assigned to receive an additional 16 days of thromboprophylaxis with 10 mg of oral rivaroxaban once daily.
Primary outcome measure
1. Adjudicated venous thromboembolism, which was defined as deep vein thrombosis involving the inferior vena cava to popliteal vein or pulmonary embolism. Ultrasonography of the lower extremity vein is a routine examination. All patients had to be examined before and after surgery. Pulmonary embolism was confirmed by computed tomographic pulmonary angiography, when the patient's symptoms are suspected to be a pulmonary embolism.
2. The primary safety outcome was bleeding, including major or clinically relevant nonmajor bleeding, according to Anderson’s criteria. Patients were followed for 90 days regarding venous thromboembolism and bleeding complications.
Secondary outcome measures
Incidence of health issues in the 90 days following the intervention:
2. Myocardial infarction
4. Wound infection.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Hip fracture who were diagnosed by X-ray and/or computed tomography.
Target number of participants
Aspirin grounp (n=198 patients); Rivaroxaban group (n=192 patients)
Participant exclusion criteria
1. Lower extremity DVT confirmed by preoperative ultrasonography
2. History of thromboembolic disease and undergoing anticoagulant therapy
3. Presence of hemorrhagic diseases and/or a major bleeding history
4. Severe liver or kidney diseases
5. Coagulation disorders
6. Allergy to enoxaparin, aspirin, or rivaroxaban
7. Platelet count less than 100*10^9 cells/L
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Chengdu Fifth People’s Hospital
No.33 Ma-shi street Wenjiang District Chengdu Sichuan Province
Department of Orthopedic Surgery, West China Hospital, Sichuan University
Investigator initiated and funded
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The intention is to publish the results of this study, in peer-reviewed journals.The results will be made available online, if permitted by journal policies.
IPD sharing statement:
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request
Intention to publish date
Participant level data
Available on request
Basic results (scientific)
The incidence of VTE in the aspirin group and rivaroxaban group was 6.6% (13/198) and 5.7% (11/192), respectively, with no significant difference between the groups (P =0.465). The rate of major bleeding events occurred in 2 (1.0%) patients in the aspirin group and in 1 (0.5%) in the rivaroxaban group without a significant difference (P=0.983). During the 90-day follow-up, a pulmonary embolism developed in 1 patient (0.5%) in the aspirin group and none in the rivaroxaban group, with no significant difference between the two groups (P=0.465).