Comparative Effectiveness of Proactive Tobacco Treatment among Smokers with and without Chronic Lower Respiratory Disease

Abstract

Rationale: Adults with chronic lower respiratory disease differ in their barriers to smoking cessation but also suffer from tobacco-related health concerns, which may motivate quit attempts. Few studies have examined differences in tobacco treatment response between smokers with and without chronic lower respiratory disease.

Objective: We examined the effectiveness of a proactive outreach program for cessation among smokers with and without chronic lower respiratory disease.

Methods: Subgroup analysis of the Veterans Victory over Tobacco Study, a pragmatic randomized controlled trial that demonstrated the effectiveness of proactive outreach and the choice of tobacco treatments compared with usual care. Smokers identified via the electronic medical record were proactively offered phone-based counseling and care coordination to receive medication from their Veterans Affairs providers or in-person care. We compared the response among those with and without an International Classification of Diseases, 9th Revision diagnosis of a chronic lower respiratory disease (chronic obstructive pulmonary disease, chronic bronchitis, emphysema, asthma). We used stratification by propensity scores to adjust for imbalanced covariates between groups with and without chronic lower respiratory disease within each treatment arm, using complete case analysis accounting for the stratified sampling by site.

Results: The study participants were predominantly older, white, male smokers. Overall, 19.6% had chronic lower respiratory disease. A total of 3,307 had outcome data with the following assignments to the intervention: proactive care: n = 1,272 without chronic lower respiratory disease, n = 301 with chronic lower respiratory disease; usual care: n = 1,387 without chronic lower respiratory disease, n = 347 with chronic lower respiratory disease. A total of 1,888 had both complete baseline and outcome data and were included in the primary analysis. In unadjusted analyses (n = 3,307), among individuals with chronic lower respiratory disease, 13.1% in the proactive group reported 6-month prolonged abstinence compared with 8.7% of those in the usual care group (odds ratio, 1.57; 95% confidence interval, 0.93-2.65). Among individuals without chronic lower respiratory disease, 13.1% quit in the proactive group compared with 11.0% in the usual care group (odds ratio, 1.22; 95% confidence interval, 0.95-1.55). In adjusted analyses (n = 1,888), the association between treatment arm and quit rate varied by the presence of chronic lower respiratory disease, with a stronger association between allocation to the proactive group and quit rate among those with chronic lower respiratory disease (odds ratio, 3.45; 95% confidence interval, 1.59-7.47) than those without chronic lower respiratory disease (odds ratio, 1.34; 95% confidence interval, 0.95-1.88; P for interaction with chronic lower respiratory disease = 0.03).

Conclusions: Smokers with chronic lower respiratory disease may be more likely to respond to a proactive outreach intervention for tobacco cessation treatment than those without chronic lower respiratory disease. Clinical trial registered with www.clinicaltrials.gov (NCT 00608426).

Keywords: chronic lower respiratory disease; chronic obstructive pulmonary disease; proactive outreach; smoking cessation.