Adherence to postoperative thromboprophylactic medication among gynecologic oncology patients: A subanalysis.

INTRODUCTION: Venous thromboembolism (VTE) is a major cause of morbidity and mortality among gynecologic cancer patients, especially in the immediate postoperative period. We sought to identify patterns related with patient non-adherence to postoperative prophylactic anticoagulation. METHODS: Participant data (N = 400) were reviewed from a previously conducted randomized controlled trial comparing the safety and efficacy of prophylactic postoperative anticoagulation with enoxaparin versus apixaban among gynecologic oncology patients. Variables hypothesized to be related to medication adherence were pre-selected by the study authors, and adherence was defined as missing ≤2 days of medication (4 pills or 2 injections) in 28 days postoperatively. For univariate comparisons and multivariate modeling, the threshold for statistical significance was set at p < .05. RESULTS: Non-adherence (N = 64) was associated with lower quality of life (QOL) score, history of anxiety disorder, decreased medication satisfaction, taking more medications at baseline, higher baseline heart rate, fewer total intraoperative procedures, not undergoing radical hysterectomy and/or lymph node dissection, not meeting 2-week postoperative milestones, and 28-day emergency department (ED) visit or readmission. African American race, lower mental QOL, difficulty remembering to take medication, and 28-day ED visit or readmission were predictive of non-adherence in a multivariate model. Patients taking enoxaparin versus apixaban more frequently attributed non-adherence to pain or bruising (25.0% vs. 3.1%, P = .01). CONCLUSION: Our findings provide new insights into factors associated with medication adherence that are particularly relevant to gynecologic oncology patients after surgery. Preoperative interventions to identify patients with these risk factors for more intensive followup of postoperative anticoagulation regimen may help increase medication adherence.

Cost-effectiveness of apixaban for prevention of venous thromboembolic events in patients after gynecologic cancer surgery.

OBJECTIVE: The cost-effectiveness of apixaban was compared with enoxaparin for prevention of postoperative venothromboembolic events (VTE) in gynecologic oncology patients. Current guidelines recommend thromboprophylaxis with low molecular weight heparin for 28 days following gynecologic cancer surgery, but recent trials suggest that oral apixaban may be a safe, patient-preferred alternative. Apixaban was superior to enoxaparin in a Canadian cost-effectiveness analysis using orthopedics trial data. METHODS: Medication costs, adherence rates, event rates, event costs, and utility decrements were estimated using prior clinical trial data and literature review for input into a short-term decision model to simulate outcomes in a hypothetical cohort of 1000 patients. Incremental cost-effectiveness ratios (ICERs) were calculated as net cost difference per quality-adjusted life year (QALY) gained. Input values at which net costs and QALYs were equivalent and ICERs at upper and lower bounds were evaluated. RESULTS: Using aggregated costs, apixaban was less expensive and more effective than enoxaparin, and remained so or had high value in all scenarios on sensitivity analysis. Examining disaggregated ICERs, apixaban was cost-effective for deep venous thrombosis (DVT); of high value for clinically-relevant non-major bleeding (CRNMB) ($411); low value for major bleeding ($183,465), VTE-related death ($2,711,229), and all-cause mortality ($297,522); and not cost-effective for pulmonary embolism prevention. CONCLUSIONS: Apixaban is more cost-effective than enoxaparin for the prevention of postoperative VTE in patients with gynecologic cancer. This appears to be driven largely by DVT and CRNMB prevention.

Safety and Efficacy of Apixaban vs Enoxaparin for Preventing Postoperative Venous Thromboembolism in Women Undergoing Surgery for Gynecologic Malignant Neoplasm: A Randomized Clinical Trial.

Importance: Current guidelines recommend a 28-day course of enoxaparin for thromboprophylaxis after surgery for gynecologic cancer. The high cost of this medication and the low adherence rates observed in prior studies provide an opportunity to benefit patients by demonstrating the safety of a more cost-effective, easier to use thromboprophylactic. Objective: To investigate the safety and efficacy of an oral treatment alternative for thromboprophylaxis in postoperative patients with gynecologic cancer. Design, Setting, and Participants: This was a patient-based, multicenter, open-label, blinded, end point, randomized clinical trial conducted May 2015 to March 2019 in outpatient and inpatient gynecologic oncology settings. Women undergoing surgery for suspected or confirmed gynecologic cancer were approached for recruitment. The trial compared rates of major bleeding and clinically relevant nonmajor bleeding events during a 90-day follow-up period in patients taking apixaban or enoxaparin for postoperative thromboprophylaxis using a modified intent-to-treat analysis. Data analysis was performed from October to December 2019. Interventions: Women were randomized to 28 days of apixaban (2.5 mg orally twice daily) or enoxaparin (40 mg subcutaneously daily). Main Outcomes and Measures: The primary outcome was major bleeding and clinically relevant nonmajor bleeding events. Secondary outcomes included incidence of venous thromboembolic events, adverse events, medication adherence, participant quality of life, and medication satisfaction. Results: Of 500 women recruited for the study, 400 were enrolled and randomized (median age, 58.0 years; range, 18.0-89.0 years); 204 received apixaban and 196 received enoxaparin. Treatment groups did not differ in terms of race/ethnicity, cancer stage, or surgery modality (open vs robotic). There were no statistically significant differences between the apixaban and enoxaparin groups in terms of rates of major bleeding events (1 patient [0.5%] vs 1 patient [0.5%]; odds ratio [OR], 1.04; 95% CI, 0.07-16.76; P > .99), clinically relevant nonmajor bleeding events (12 patients [5.4%] vs 19 patients [9.7%]; OR, 1.88; 95% CI, 0.87-4.1; P = .11), venous thromboembolic events (2 patients [1.0%] vs 3 patients [1.5%]; OR, 1.57; 95% CI, 0.26-9.50; P = .68), adverse events, medication adherence, or quality of life between the groups. Participant satisfaction was significantly greater in the apixaban group with regard to ease of taking the medication (186 patients [98.9%] vs 110 patients [58.8%]; OR, 0.06; 95% CI, 0.01-0.25; P < .001) and pain associated with taking the medication (4 patients [2.1%] vs 92 patients [49.2%]; OR, 9.20; 95% CI, 2.67-31.82; P < .001). Conclusions and Relevance: These findings suggest that oral apixaban is a potentially safe, less painful, and easier-to-take alternative to subcutaneous enoxaparin for thromboprophylaxis after surgery for gynecologic cancer. The efficacy of apixaban to prevent venous thromboembolic events is hypothesized as being equivalent. Trial Registration: ClinicalTrials.gov Identifier: NCT02366871.