Nicotine replacement therapy works best when used in conjunction with a support program, such as counseling, group therapy, or behavioral therapy. Nicotine chewing gum, if chewed correctly, increases quit rates up to 2-fold. At 1 year, the abstinence rate with the patch is 20%. At 4 years, the abstinence rate is 12.4%, as opposed to 4.5% with placebo. Nicotine patches are sold under various trade names (see below).