Patient preferences for venous thromboembolism prophylaxis after injury: a discrete choice experiment

OBJECTIVE Limited evidence for the optimal venous thromboembolism (VTE) prophylaxis regimen in orthopaedic trauma leads to variability in regimens. We sought to delineate patient preferences towards cost, complication profile, and administration route (oral tablet vs. subcutaneous injection). DESIGN Discrete choice experiment (DCE). SETTING Level 1 trauma center in Baltimore, USA. PARTICIPANTS 232 adult trauma patients (mean age 47.9 years) with pelvic or acetabular fractures or operative extremity fractures. PRIMARY AND SECONDARY OUTCOME MEASURES Relative preferences and trade-off estimates for a 1% reduction in complications were estimated using multinomial logit modelling. Interaction terms were added to the model to assess heterogeneity in preferences. RESULTS Patients preferred oral tablets over subcutaneous injections (marginal utility, 0.16; 95% CI: 0.11 - 0.21, P<0.0001). Preferences changed in favor of subcutaneous injections with an absolute risk reduction of 6.98% in bleeding, 4.53% in wound complications requiring reoperation, 1.27% in VTE, and 0.07% in death from pulmonary embolism (PE). Patient characteristics (sex, race, type of injury, time since injury) affected patient preferences (P<0.01). CONCLUSIONS Patients preferred oral prophylaxis and were most concerned about risk of death from PE. Furthermore, the findings estimated the trade-offs acceptable to patients and heterogeneity in preferences for VTE prophylaxis.