Review: all forms of nicotine replacement therapy are effective for smoking cessation.

Study selection and assessment: randomised controlled trials (RCTs) >6 months in duration that compared NRT (including gum, transdermal patch, intranasal spray, and inhaled and oral preparations) with placebo or no treatment, or compared different doses of NRT, and assessed smoking cessation. Methodological quality of individual trials was assessed for randomisation method, outcome assessment, and bias control.