The effectiveness of varenicline versus nicotine replacement therapy on long-term smoking cessation in primary care: a prospective cohort study of electronic medical records.

Gemma Mj Taylor,Marcus R Munafò,Timothy Jones,Kyla H Thomas,Neil M Davies,Frank Windmeijer,Amy E Taylor,Richard M Martin

doi:10.1093/ije/dyx109

Abstract

BackgroundThere is limited evidence about the effectiveness of varenicline and nicotine replacement therapy (NRT) for long-term smoking cessation in primary care, or whether the treatment effectiveness differs by socioeconomic position (SEP). Therefore, we estimated the long-term effectiveness of varenicline versus NRT (> 2 years) on smoking cessation, and investigated whether effectiveness differs by SEP.MethodsThis is a prospective cohort study of electronic medical records from 654 general practices in England, within the Clinical Practice Research Datalink, using three different analytical methods: multivariable logistic regression, propensity score matching and instrumental variable analyses. Exposure was prescription of varenicline versus NRT, and the primary outcome was smoking cessation at 2 years’ follow-up; outcome was also assessed at 3, 6, and 9 months, and at 1 and 4 years after exposure. SEP was defined using the Index of Multiple Deprivation.ResultsAt 2 years, 28.8% (N = 20 362/70 610) of participants prescribed varenicline and 24.3% (N = 36 268/149 526) of those prescribed NRT quit; adjusted odds ratio was 1.26 [95% confidence interval (CI): 1.23 to 1.29], P < 0.0001. The association persisted for up to 4 years and was consistent across all analyses. We found little evidence that the effectiveness of varenicline differed greatly by SEP. However, patients from areas of higher deprivation were less likely to be prescribed varenicline; adjusted odds ratio was 0.91 (95% CI: 0.90 to 0.92), P < 0.0001.ConclusionsPatients prescribed varenicline were more likely to be abstinent up to 4 years after first prescription than those prescribed NRT. In combination with other evidence, the results from this study may be used to update clinical guidelines on the use of varenicline for smoking cessation.

Highlights

Tobacco is the world’s leading preventable cause of serious illness and premature death.[1]
149 526 patients prescribed nicotine replacement therapy (NRT) and 70 610 patients prescribed varenicline were eligible for analysis
Of those prescribed NRT, a range of products was prescribed including patches, gum, oral spray, nasal spray, oral film, inhaler, lozenges and microtab; 34 396 (23%) of the patients prescribed NRT were prescribed more than one nicotine product

Summary

Introduction

Tobacco is the world’s leading preventable cause of serious illness and premature death.[1]. Anthenelli and colleagues (2016) reported that those treated with varenicline achieved higher rates of abstinence compared with NRT at 24 weeks; odds ratio (and 95% confidence interval) were 1.5 (1.3 to 1.8).[5] Cahill and colleagues conducted a network meta-analysis of RCTs which suggested that varenicline is the most efficacious smoking cessation medicine at up to 12 months; odds ratio (and 95% confidence interval) were 1.6 (1.3 to 1.9).[7] the efficacy of treatments in trial settings may differ from their effectiveness in everyday clinical settings because of variation in treatment delivery and participant characteristics. There is limited evidence about the effectiveness of varenicline and nicotine replacement therapy (NRT) for long-term smoking cessation in primary care, or whether the treatment effectiveness differs by socioeconomic position (SEP).

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