Adherence to varenicline and associated smoking cessation in a community-based patient setting

Varenicline, a selective α4β2 nicotinic acetylcholine receptor partial agonist, is a pharmacotherapy indicated for smoking cessation treatment. To our knowledge, no studies have described varenicline treatment adherence and efficacy from real-world treatment patterns in a U.S. primary care setting.

To estimate adherence to varenicline prescription orders and subsequent quit rates among smokers in a primary care setting.

In this retrospective cohort study, eligible patients were enrolled with Geisinger Health Plan, had an initial varenicline prescription written by a Geisinger provider between January 1, 2006, and December 31, 2009, and had a follow-up clinic visit within the subsequent 12 months. Adherence was derived from linking electronic prescriptions with adjudicated pharmacy claims. Smoking status was collected at each health care encounter.

Of the 1,477 eligible patients, 823 (55.7%) were primary nonadherent, having failed to initiate on the prescribed varenicline therapy. Of the remaining 654 patients, 359 (54.9%) were adherent, having completed a full 12-week course of therapy, and 295 (45.1%) were partially adherent, having initiated but not completed the full course of therapy. A total of 521 patients (35.3%) ceased smoking during the 12-month follow-up period: 182 (50.7%) of the adherent cohort, 82 (27.8%) of the partially adherent population, and 257 (31.2%) of the nonadherent cohort. No significant difference was found in quit rates between the partially adherent and nonadherent patient cohorts (adjusted HR 0.88 [95% CI=0.69-1.13]). However, patients adherent to the varenicline regimen were almost twice as likely to succeed in quitting smoking compared with completely nonadherent patients (HR 1.93 [95% CI=1.59-2.33]).

Smoking cessation occurred more often among individuals adherent to varenicline therapy; however, medication nonadherence was common. After prescribing varenicline, clinicians and payers could consider active patient follow-up to maximize adherence and optimize treatment outcomes.