• smoking cessation
• nicotine replacement therapy
• hospital inpatients

Most smokers become nicotine dependent and, when they stop smoking, experience withdrawal symptoms and craving. Nicotine replacement therapy (NRT) reduces these unpleasant symptoms and, theoretically, should decrease the risk of relapse. Smoking cessation is properly defined as validated sustained abstinence from cigarettes and/or other tobacco products for at least 6 months, but preferably for 1 year. This editorial includes evidence only from those studies which have applied such a definition and which have specified their settings and populations.

NRT is available as chewing gum, transdermal patches, sublingual tablets, lozenges, inhalation cartridges and nasal spray. In specialised cessation clinics^1–8 and in primary care,^9,10 prospective randomised clinical trials have shown that NRT, used as an adjunct to advice and support, results in better cessation rates than does advice and support alone. In the clinics success rates with NRT tend to be higher (11–30%) and more consistent than in primary care, where some studies have found no significant difference from placebo.^11–14 One study in primary care showed 8% success with nicotine chewing gum compared with 4% with advice plus leaflet, but there was no placebo controlled arm.¹⁵ Two studies of transdermal nicotine in primary care have shown success rates of around 10%, which were superior to those with placebo (around 6%).^9,10 The benefit for transdermal nicotine in cessation clinics^6–8 and in primary care^9,10 is thus clear, whereas nicotine chewing gum,^1–5 inhaler,^16,17 …