Impact of compliance on quit rates in a smoking cessation intervention: population study in Denmark

Abstract

Objectives Primary objective was to evaluate whether patients completing at least 75% of the smoking cessation program had a higher quit rate after 6 months than patients participating in less than 75% of the program. Secondary objective was to evaluate whether there might be a more appropriate compliance level than 75%. Methods The study included all patients (17,439) who participated in the National Gold Standard Smoking Cessation Program in Denmark (GSP) with planned follow-up for smoking cessation at 6 months. Patients were randomly divided into two groups (datasets) in order to investigate and re-validate the objectives on two separated groups of smokers. Sensitivity analyses were undertaken for non-responders. Results Patients who completed at least 75% of the program sessions had higher quit rates in comparison to patients who completed less than 75% of the program (OR = 0.27; 95% CI 0.24 - 0.31 and 0.31; 0.27 - 0.35) for the first and second dataset, respectively. However patients who completed the whole program had higher quit rates compared to patients completing only 75% (0.49; 0.43 - 0.56, and 0.54; 0.47 - 0.62, respectively). The sensitivity analysis showed that baseline characteristics were similar between patients with missing and available follow-up data. Conclusion Compliance to 75% of the national smoking cessation program (GSP) is shown to be effective; however, 100% compliance leads to even higher quit rates.