Prevalence of NRT Use and Associated Nicotine Intake in Smokers, Recent Ex-Smokers and Longer-Term Ex-Smokers

BACKGROUND Nicotine replacement therapy (NRT) is used by smokers wanting to reduce their smoking and to quit. However, there are very little data on nicotine intake associated with NRT use in representative population samples. This study aimed to provide estimates for NRT use and associated nicotine exposure among smokers, recent and longer-term ex-smokers in England, a country with a permissive regulatory regime for nicotine substitution. METHODS In the Smoking Toolkit Study, a monthly series of representative household surveys of adults aged 16+ in England, current and recent ex-smokers who agreed to be re-contacted were followed up 6 months later and standard socio-demographic and smoking characteristics assessed (N = 5,467, response rate 25.1%). A random sub-sample (N = 1,614; 29.5%) also provided saliva, analysed for cotinine. RESULTS The sample followed up was broadly representative of the original sample. At follow-up, 11.8% (95%CI 10.9-12.8, N = 565) of current smokers, 34.8% (95%CI 28.9-41.3, N = 77) of recent (≤ 3 months) ex-smokers, and 7.8% (95%CI 5.6-10.6, N = 36) of longer-term (> 3 months) ex-smokers reported using NRT. Smokers who used NRT had similar saliva cotinine concentrations to smokers who did not use NRT (mean ± sd  = 356.0 ± 198.6 ng/ml vs. 313.1 ± 178.4 ng/ml). Recent ex-smokers who used NRT had levels that were somewhat lower, but not significantly so, than current smokers (216.7 ± 179.3 ng/ml). Longer-term ex-smokers using NRT had still lower levels (157.3 ± 227.1 ng/ml), which differed significantly from smokers using NRT (p = 0.024). CONCLUSIONS Concurrent use of nicotine replacement therapy while smoking is relatively uncommon and is not associated with higher levels of nicotine intake. Among ex-smokers, NRT use is common in the short but not longer-term and among longer-term users is associated with lower nicotine intake than in smokers.