Healthcare professionals, including nurses, frequently advise patients to improve their health by stopping smoking. Such advice may be brief, or part of more intensive interventions. To determine the effectiveness of nursing-delivered smoking cessation interventions. We searched the Cochrane Tobacco Addiction Group specialized register and CINAHL in July 2007. Randomized trials of smoking cessation interventions delivered by nurses or health visitors with follow up of at least six months. Two authors extracted data independently. The main outcome measure was abstinence from smoking after at least six months of follow up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where statistically and clinically appropriate, we pooled studies using a Mantel-Haenszel fixed effect model and reported the outcome as a risk ratio (RR) with 95% confidence interval (CI). Forty-two studies met the inclusion criteria. Thirty-one studies comparing a nursing intervention to a control or to usual care found the intervention to significantly increase the likelihood of quitting (RR 1.28, 95% CI 1.18 to 1.38). There was heterogeneity among the study results, but pooling using a random effects model did not alter the estimate of a statistically significant effect. In a subgroup analysis there was weaker evidence that lower intensity interventions were effective (RR 1.27, 95% CI 0.99 to 1.62). There was limited indirect evidence that interventions were more effective for hospital inpatients with cardiovascular disease than for inpatients with other conditions. Interventions in non-hospitalized patients also showed evidence of benefit. Nine studies comparing different nurse-delivered interventions failed to detect significant benefit from using additional components. Five studies of nurse counselling on smoking cessation during a screening health check, or as part of multifactorial secondary prevention in general practice (not included in the main meta-analysis) found nursing intervention to have less effect under these conditions. The results indicate the potential benefits of smoking cessation advice and/or counselling given by nurses to patients, with reasonable evidence that intervention is effective. The evidence of an effect is weaker when interventions are brief and are provided by nurses whose main role is not health promotion or smoking cessation. The challenge will be to incorporate smoking behaviour monitoring and smoking cessation interventions as part of standard practice, so that all patients are given an opportunity to be asked about their tobacco use and to be given advice and/or counselling to quit along with reinforcement and follow up.
