Patient adherence and satisfaction with self-administration of prophylactic Low Molecular Weight Heparin (LMWH) after orthopaedic trauma surgery: a prospective observational cohort study

BACKGROUND: Data on patients' adherence and satisfaction with prophylactic low molecular weight heparin (LMWH) after orthopaedic trauma surgery are lacking. OBJECTIVES: This observational prospective cohort study aimed to investigate adherence and satisfaction with subcutaneous self-administration of LMWH as postoperative thromboprophylaxis in orthopaedic trauma patients. PATIENTS/METHODS: One hundred adult patients who were prescribed ≥4 weeks of prophylactic LMWH after unplanned fracture surgery were included. After completing four weeks of LMWH, all patients received a questionnaire on administration adherence (Morisky Medication Adherence Scale 4-item; MMAS-4) and satisfaction (Anti-Clot Treatment Scale; ACTS) with LMWH, pain medication use and adverse effects of subcutaneous self-administration of LMWH at the injection site. RESULTS: Fifty-four patients reported high adherence with the administration of the prescribed LMWH (MMAS-4 score of 4), 29 patients reported moderate adherence (MMAS-4 score of 2-3) and 17 reported low adherence (MMAS-4 score of 0-1). The 46 patients with moderate/low adherence had a higher risk of adverse events at the injection site than the 54 patients with high adherence (bruising: OR2.81, 95% CI: 0.99-7.93); pain: OR8.27, 95% CI: 3.36-20.39); swelling: OR 3.58, 95% CI:1.32-9.73); minor bleeding: OR 4.27, 95% CI:1.50-12.11) and were less satisfied with their treatment (mean difference ACTS Benefits scale score: 2.0, 95% CI: 0.9-3.2; p < 0.001; mean difference ACTS Burdens scale score: 7.9, 95% CI: 5.3-10.5; p < 0.001). CONCLUSION: Nearly half of the patients reported moderate or low adherence with prophylactic LMWH after orthopaedic trauma surgery. As adherence may influence prophylactic effectiveness and increase postoperative venous thromboembolism risk, further investigations into more user-friendly alternatives are an unmet need.