Association of Out-of-Pocket Pharmacy Costs with Adherence to Varenicline

Abstract

BACKGROUND: Varenicline, a nicotinic acetylcholine receptor partial agonist, is a pharmacotherapy indicated for smoking cessation treatment. To date, no research has examined the relationship between out-of-pocket (OOP) expense and varenicline adherence among Medicare beneficiaries.OBJECTIVES: To (a) characterize medication utilization patterns of varenicline among Medicare members newly initiated on varenicline and (b) examine the relationship between member OOP expense and varenicline medication adherence.METHODS: In this retrospective cohort study, pharmacy claims data were used to identify Medicare Advantage Prescription Drug Plan (MAPD) members newly initiated on varenicline. Demographic and clinical characteristics, varenicline medication utilization patterns, and pharmacy costs (total and varenicline-specific) were determined for members included in the study. Varenicline adherence was measured by calculating the proportion of days covered (PDC) over a period of 84 days (12 weeks) after initiation. Multiple regression analysis was used to examine the relationship between varenicline OOP cost and varenicline medication utilization, while controlling for sociodemographic characteristics, clinical factors, and nonvarenicline pharmacy costs.RESULTS: A total of 15,452 MAPD members were included in the analysis. Mean (SD) subject age was 62.6 (10.0) years; 21.1% (n = 3,256) were dual eligible; and 33.0% (n = 5,106) received a low-income subsidy. Mean (SD) initial varenicline treatment episode duration was 50.8 (37.8) days, with a mean (SD) varenicline days' supply of 47.8 (32.6) obtained by members during the initial treatment episode. Mean (SD) PDC was 0.51 (0.24), and 14.9% (n = 2,302) of members were classified as adherent to treatment (PDC ≥ 0.80). Greater varenicline OOP expense was significantly associated with lower PDC (regression coefficient = -0.058, P < 0.001) and significantly associated with lower odds of receiving a refill for varenicline (odds ratio 0.594, 95% CI: 0.540-0.655, P < 0.001).CONCLUSIONS: Among Medicare beneficiaries newly initiated on varenicline, medication adherence was suboptimal, and greater OOP cost was associated with lower adherence and lower odds of refilling varenicline.

Varenicline for smoking cessation: a narrative review of efficacy, adverse effects, use in at-risk populations, and adherence

“…Better adherence to varenicline improves outcomes but adherence is often suboptimal. 52 Suehs et al 53 retrospectively evaluated pharmacy claims data to examine the relationship between out-of-pocket expenses and varenicline utilization. Adherence was calculated based upon medications dispensed as covered for up to 12 weeks after initial coverage.…”

Medication adherence 1 month after hospital discharge in medical inpatients

“…This is particularly true of treatment for asymptomatic disease, as patients cannot see a tangible benefit of their medication. Similarly, medications with high cost have been shown to be associated with higher rates of non‐adherence . A good physician–patient relationship is also imperative in improving medication adherence, and it is plausible that this is due to better education of patients about the importance of their medications.…”

“…Adherence rates, predictors and barriers to adherence vary between populations, cultural groups, disease types and medication classes . Predictors of non‐adherence include poor health, cognitive impairment, asymptomatic disease, inadequate follow up, side effects, non‐belief in therapy, polypharmacy, complex regimens, poor relationship with physicians and medication cost …”

“…4,10,11 Predictors of nonadherence include poor health, cognitive impairment, asymptomatic disease, inadequate follow up, side effects, non-belief in therapy, polypharmacy, complex regimens, poor relationship with physicians and medication cost. 1,[12][13][14][15][16][17][18] The majority of data on medication adherence comes from overseas studies. It is important to validate these studies in an Australian patient population, as our public healthcare system is substantially different to those overseas.…”

Effect of 0.5 mg versus 1 mg varenicline for smoking cessation: a randomized controlled trial

“…Poor adherence is often due to financial reasons , as in Spain the drug is not subsidized by the Spanish Public Health System. A recent study in the Netherlands showed that results clearly improved when the drug began to be reimbursed by the state once again, following a period during which reimbursement had been suspended .…”