How can smoking cessation be induced before surgery? A systematic review and meta-analysis of behaviour change techniques and other intervention characteristics

Background: Smokers who continue to smoke up to the point of surgery are at increased risk of a range of complications during and following surgery. Objective: To identify whether behavioural and/or pharmacological interventions increase the likelihood that smokers quit prior to elective surgery and which intervention components are associated with larger effects. Design: Systematic review with meta-analysis. Data Sources: MEDLINE, Embase and Embase Classic, CINAHL, CENTRAL. Study Selection: Studies testing the effect of smoking reduction interventions delivered at least 24 hours before elective surgery were included. Study appraisal and synthesis: Potential studies were independently screened by two people. Data relating to study characteristics and risk of bias were extracted. The effects of the interventions on pre-operative smoking abstinence were estimated using random effects meta-analyses. The association between specific intervention components (behaviour change techniques; mode; duration; number of sessions; interventionist) and smoking cessation effect sizes were estimated using meta-regressions. Results: Twenty-two studies comprising 2992 smokers were included and 19 studies were meta-analysed. Interventions increased the proportion of smokers who were abstinent or reduced smoking by surgery relative to control: g = 0.56, 95% CI 0.32 - 0.80, with rates nearly double in the intervention (46.2%) relative to the control (24.5%). Interventions that comprised more sessions, delivered face-to-face and by nurses, as well as specific behaviour change techniques (providing information on consequence of smoking/cessation; providing information on withdrawal symptoms; goal setting; review of goals; regular monitoring by others; and giving options for additional or later support) were associated with larger effects. Conclusion: Rates of smoking can be halved prior to surgery and a number of intervention characteristics can increase these effects. There was, however, some indication of publication bias meaning the benefits of such interventions may be smaller than estimated.