M. E. Moya-Mendez1, D. Schaps1, K. N. Penvose1, D. Chang1, J. Migaly1 1Duke University Medical Center, Department Of Surgery, Durham, NC, USA
Introduction: Patients undergoing major pelvic or abdominal oncologic surgery should undergo chemical thromboprophylaxis to reduce risk of venous thromboembolism (VTE) – the most common cause of preventable death following these operations. Most literature evaluates prescription filling to determine adherence to low-molecular-weight heparin (LMWH), but this approach fails to discriminate between prescription filling and true compliance. The purpose of this study was to determine the self-reported weekly adherence to LMHW for patients who underwent major colorectal surgery for cancer.
Methods: Patients undergoing major colorectal surgery for colorectal cancer from 7/29/2022-2/28/2023 and being discharged with 4-weeks of LMWH injections were approached for consent. If the patient participated, demographic information was collected, and they were contacted weekly by phone to answer the Voils Domains of Subjective Extent of Nonadherence survey.
Results: Of 95 patients, 42 (44%) agreed to participate. Of these patients, 3 (7%) were lost to follow-up. Of these 39 patients, 59% were female, 28% were Black/African-American, 5% were Hispanic, 13% had received LMWH shots previously, 28% reported being “moderately” or “very” fearful of needles, 36% had utilized injected medications, and 3% previously had VTE. The average post-operative Caprini VTE Score was 7.6 which is deemed as “High Risk” and necessitates VTE prophylaxis. LMWH injection adherence was 97% during week one, 77% in week two, 87% in week three, and 85% in week four. Overall, 62% of patients were adherent through the four-week period. Most common reasons for nonadherence were feeling out of routine (93%), forgetting (47%), and remembering too late in the day (40%).
Conclusion: We found that adherence to thromboprophylaxis with injected LMWH after colorectal surgery for cancer was poor. Given that the most commonly selected reasons for missing LMWH dosages were related to patients forgetting, being out of their normal routine, and lacking appropriate supplies, this suggests that programs should be constructed to focus on opportunities for patient behavioral modifications to promote adherence. More research is needed to determine optimal intervention techniques to increase adherence.
