Smoking harm reduction approaches: a rapid review of the literature

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Introduction

Smoking is the leading preventable cause of disease and death in Wales. Help Me Quit currently follows NICE guidance by supporting smokers to make an ‘abrupt quit’, where a quit date is set and smoking stops entirely. However, many smokers are not ready or able to quit suddenly. For these individuals, NICE recommends discussing harm reduction approaches, working with each person to identify suitable strategies and set achievable goals.

Harm reduction options include:
• Cutting down before quitting with behavioural support
• Reducing smoking without quitting, using behavioural support
• Temporarily stopping smoking

Nicotine replacement therapy (NRT) is recommended for harm reduction by substituting cigarettes fully or partly, or by reducing cravings. NRT is considered safe and effective for cutting down, is better than continued smoking, increases the chance of quitting, reduces compensatory smoking (taking deeper puffs from fewer cigarettes), and can be used indefinitely to prevent relapse.

E‑cigarettes are not recommended for harm reduction because they are not medically licensed or regulated, and evidence on their safety, quality and effectiveness is lacking. Although likely to be less harmful than smoking, licensed nicotine products are the preferred option.

Most evidence underpinning harm reduction guidance was published before 2015. This rapid review therefore aims to update the evidence base on harm reduction approaches. It summarises what works for adults who are not yet ready to attempt an abrupt quit, with the purpose of informing future developments of the Help Me Quit service to help people reduce smoking or progress gradually towards quitting.

Main points

How up to date is this evidence?

This rapid review searched for primary studies published since 2015.

What we found

• No strong new evidence was found that would justify departure from NICE guidance. Developments of Help Me Quit to support people not ready to commit to a quit should follow existing guidance.
• We looked for any interventions to reduce exposure to tobacco smoking that doesn’t involve an abrupt quit. Goals for reducing smoking could be set alone or alongside longer-term goals to quit smoking.
• Nine randomised trials were included in the review, examining behavioural support alone, or in combination with NRT or prescribed medication (varenicline).
• Varenicline plus behavioural support had clear evidence of benefit from one high-quality multinational trial, improving both smoking reduction and verified abstinence.
• Behavioural support alone helped some people reduce smoking in the short term but showed no sustained effect on verified abstinence in three diverse interventions.
• NRT plus behavioural support had no evidence of improving verified reduction or abstinence in four poorer quality studies.
• Self‑reported outcomes often greatly overestimated success compared with verified measures.
• Only two studies reported harms or cost‑effectiveness, so the overall balance of harm to benefit is uncertain.

Technical information

This rapid review searched for primary studies published since 2015. It included randomised controlled trials involving adults who smoke but are not ready to set a quit date. Interventions could be any approach to reduce exposure to tobacco smoking that doesn’t involve an abrupt quit. Goals for reducing smoking could be set alone or alongside longer-term goals to quit smoking. Outcomes included verified changes in smoking behaviour, reduction and abstinence. Evidence was synthesised narratively due to variation in interventions and outcome measures.

Glossary

NRT: Nicotine replacement therapy is a treatment that provides nicotine in a safer form—such as patches, gum, lozenges, inhalators, or sprays—to help reduce withdrawal symptoms and cravings when a person is trying to stop smoking.

Varenicline: also known as Champix is a prescribed medication that works by reducing symptoms of withdrawal and blocking some of the ‘rewarding’ effects of smoking, making quitting easier and relapse less likely.

Stakeholders

Health Improvement division, PHW.