Healthcare costs and impact of medication adherence on outcomes in patients on novel anticoagulant therapy

Objective: The study was designed to evaluate the extent of undertreatment (adherence), and its predictors along with the impact of adherence on clinical outcomes, including ischemic stroke, bleeding, and Deep Vein Thrombosis and Pulmonary Embolism (DVTPE). Furthermore, the analysis helped to estimate the economic burden of NOACs vs. warfarin and identify specific subgroups with high-cost drivers and Healthcare Resource Utilization (HCRU) to achieve optimal benefits and devise strategies for cost-savings. Methods: The research utilized a retrospective cohort study design. Atrial fibrillation patients (ICD-9-CM codes 427.31/32), with ≥2 prescription fills for NOAC or warfarin, CHA2DS2VASC score ≥1, and 6-months pre-index continuous enrollment from the Optum® Clinformatics™ Data Mart (Optum Insight, Eden Prairie, MN) (Jan 1, 2010 and Dec 31, 2012) were included. Results: A total of 5057 (N=1770 NOAC vs. N=3287 warfarin) patients with mean age of 66 years were included in the cohort based on the inclusion and exclusion criteria. For a 12-month follow-up, the proportion of adherent (PDC ?80%) patients were higher among NOACs users (78.42%) compared to warfarin users (61.88%). Using multivariate logistic model controlling for the confounders; Age, CCI and statin use were major predictors of both short (6-month) and long-term (12-month) adherence to NOACs. The CHA2DS2VASC score was significantly associated with the short-term adherence while but not associated with the long-term adherence. Overall, among warfarin users, female patients had higher HCRU, patients from the South had higher medical costs and office visits. Highest cost drivers for drug cost for warfarin users was patients from Northeast. Conversely, highest cost drivers for medical cost were patients less than \u3c65 years and patients with CCI +3. For NOACs, the highest cost driver for the drugs was user who were 65 and above, from Northeast, CHA2DS2VASC \u3e2 (mod-high risk), and independent insurance. Additionally, medical cost was driven by EPO insurance and CCI+3. Although medical costs and HCRU were lower for adherent vs. non-adherent patients taking NOACs, the differences were non-significant. Conclusion: Use of NOACs due to its better adherence compared to warfarin may help prevent inadequate anticoagulation and complications. Determining the factors influencing the adherence such as age, CCI, and stroke risk can help plan targeted approaches and interventions to improve adherence. Our results can help healthcare providers and managed care organizations to recognize the importance of adherence to NOAC medications among patients to prevent clinical risks including stroke, DVTPE and bleeding events. The study provides a valuable estimate of the economic burden in AF patients using NOACs and warfarin. These cost estimates can be further used as inputs in the studies involving cost-effectiveness analysis and indirect treatment comparisons. We found the higher drug costs for NOACs were offset by lower inpatient costs, outpatient costs, and HCRU; which can lead to overall monetary savings to the patient taking NOACs and to the healthcare system. Overall, the conducted research provides comprehensive evidence to help support NOACs as an optimal treatment choice for the AF patients. (Abstract shortened by ProQuest.