Background
Nicotine replacement therapy (NRT) aims to replace nicotine from cigarettes. This helps to reduce cravings and withdrawal symptoms, and ease the transition from cigarette smoking to complete abstinence. Although there is high‐certainty evidence that NRT is effective for achieving long‐term smoking abstinence, it is unclear whether different forms, doses, durations of treatment or timing of use impacts its effects.
Objectives
To determine the effectiveness and safety of different forms, deliveries, doses, durations and schedules of NRT, for achieving long‐term smoking cessation.
Search methods
We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning NRT in the title, abstract or keywords, most recently in April 2022.
Selection criteria
We included randomised trials in people motivated to quit, comparing one type of NRT use with another. We excluded studies that did not assess cessation as an outcome, with follow‐up of fewer than six months, and with additional intervention components not matched between arms. Separate reviews cover studies comparing NRT to control, or to other pharmacotherapies.
Data collection and analysis
We followed standard Cochrane methods. We measured smoking abstinence after at least six months, using the most rigorous definition available. We extracted data on cardiac adverse events (AEs), serious adverse events (SAEs) and study withdrawals due to treatment.
Main results
We identified 68 completed studies with 43,327 participants, five of which are new to this update. Most completed studies recruited adults either from the community or from healthcare clinics. We judged 28 of the 68 studies to be at high risk of bias. Restricting the analysis only to those studies at low or unclear risk of bias did not significantly alter results for any comparisons apart from the preloading comparison, which tested the effect of using NRT prior to quit day whilst still smoking.
There is high‐certainty evidence that combination NRT (fast‐acting form plus patch) results in higher long‐term quit rates than single form (risk ratio (RR) 1.27, 95% confidence interval (CI) 1.17 to 1.37; I
2
= 12%; 16 studies, 12,169 participants). Moderate‐certainty evidence, limited by imprecision, indicates that 42/44 mg patches are as effective as 21/22 mg (24‐hour) patches (RR 1.09, 95% CI 0.93 to 1.29; I
2
= 38%; 5 studies, 1655 participants), and that 21 mg patches are more effective than 14 mg (24‐hour) patches (RR 1.48, 95% CI 1.06 to 2.08; 1 study, 537 participants). Moderate‐certainty evidence, again limited by imprecision, also suggests a benefit of 25 mg over 15 mg (16‐hour) patches, but the lower limit of the CI encompassed no difference (RR 1.19, 95% CI 1.00 to 1.41; I
2
= 0%; 3 studies, 3446 participants...