Long-Term Outcomes From Repeated Smoking Cessation Assistance in Routine Primary Care

Purpose:To test the association between repeated clinical smoking cessation support and long-term cessation.Design:Retrospective, observational cohort study using structured and free-text data from electronic health records.Setting:Six diverse health systems in the United States.Participants:Patients aged ≥18 years who were smokers in 2007 and had ≥1 primary care visit in each of the following 4 years (N = 33 691).Measures:Primary exposure was a composite categorical variable (comprised of documentation of smoking cessation medication, counseling, or referral) classifying the proportions of visits for which patients received any cessation assistance (<25% (reference), 25%-49%, 50%-74%, and ≥75% of visits). The dependent variable was long-term quit (LTQ; yes/no), defined as no indication of being a current smoker for ≥365 days following a visit where nonsmoker or former smoker was indicated.Analysis:Mixed effects logistic regression analysis adjusted for age, sex, race, and comorbidities, with robust stand...