Interventions to reduce harm from continued tobacco use

• Published in: Cochrane database of systematic reviews 2016-10, Vol.10 (10), p.CD005231
• Main Authors: Lindson-Hawley, Nicola, Hartmann-Boyce, Jamie, Fanshawe, Thomas R, Begh, Rachna, Farley, Amanda, Lancaster, Tim
• Format: Article
• Language: English
• Subjects: Biomarkers - blood; Bupropion - therapeutic use; Carbon Monoxide - blood; Cotinine - blood; Electronic Nicotine Delivery Systems; Humans; Interventions to reduce harm in people who use tobacco; Lungs & airways; Nicotine - therapeutic use; Nicotinic Agonists - therapeutic use; Randomized Controlled Trials as Topic; Smoking - adverse effects; Smoking - blood; Smoking Cessation - methods; Smoking Prevention; Tobacco Use Cessation Devices; Tobacco Use Disorder - therapy; Tobacco, drugs & alcohol
• ISSN: 1469-493X; 1469-493X
• DOI: 10.1002/14651858.cd005231.pub3

Although smoking cessation is currently the only guaranteed way to reduce the harm caused by tobacco smoking, a reasonable secondary tobacco control approach may be to try and reduce the harm from continued tobacco use amongst smokers unable or unwilling to quit. Possible approaches to reduce the exposure to toxins from smoking include reducing the amount of tobacco used, and using less toxic products, such as pharmaceutical, nicotine and potential reduced-exposure tobacco products (PREPs), as an alternative to cigarettes. To assess the effects of interventions intended to reduce the harm to health of continued tobacco use, we considered the following specific questions: do interventions intended to reduce harm have an effect on long-term health status?; do they lead to a reduction in the number of cigarettes smoked?; do they have an effect on smoking abstinence?; do they have an effect on biomarkers of tobacco exposure?; and do they have an effect on biomarkers of damage caused by tobacco? We searched the Cochrane Tobacco Addiction Group Trials Register (CRS) on the 21st October 2015, using free-text and MeSH terms for harm reduction, smoking reduction and cigarette reduction. Randomized or quasi-randomized controlled trials of interventions to reduce the amount smoked, or to reduce harm from smoking by means other than cessation. We include studies carried out in smokers with no immediate desire to quit all tobacco use. Primary outcomes were change in cigarette consumption, smoking cessation and any markers of damage or benefit to health, measured at least six months from the start of the intervention. We assessed study eligibility for inclusion using standard Cochrane methods. We pooled trials with similar interventions and outcomes (> 50% reduction in cigarettes a day (CPD) and long-term smoking abstinence), using fixed-effect models. Where it was not possible to meta-analyse data, we summarized findings narratively. Twenty-four trials evaluated interventions to help those who smoke to cut down the amount smoked or to replace their regular cigarettes with PREPs, compared to placebo, brief intervention, or a comparison intervention. None of these trials directly tested whether harm reduction strategies reduced the harms to health caused by smoking. Most trials (14/24) tested nicotine replacement therapy (NRT) as an intervention to assist reduction. In a pooled analysis of eight trials, NRT significantly increased the likelihood of reducing CPD by at lea