Public Health: Prevention, health promotion and behaviour change

🌍 Prevention, health promotion and behaviour change. Smoking, poor diet, physical inactivity and alcohol are the leading modifiable causes of death and disability in the UK. Doctors can change outcomes through brief interventions in every consultation, through referral to effective services, and through advocacy for population measures such as taxation and regulation. This chapter covers the main risk factors, the models of behaviour change that underpin brief interventions, and the evidence for what works.
Your four questions: Which risk factors does this person have? Are they ready to change, and what would help (capability, opportunity, motivation)? What brief intervention and referral can I offer today? What population measures address the same problem?

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Health Promotion - Concepts

• WHO Ottawa Charter (1986) - five action areas: build healthy public policy; create supportive environments; strengthen community action; develop personal skills; reorient health services towards prevention.
• Health education (information and skills) is only one part of health promotion; information alone rarely changes behaviour.
• Tannahill model - overlapping spheres of health education, prevention and health protection (laws, policies).
• Social marketing - commercial marketing techniques applied to health (e.g. "Change4Life", "Stoptober").
• Nudge theory - changing the "choice architecture" so the healthy choice is the easy choice (defaults, placement, portion size), without restricting choice.
• Fiscal and regulatory measures - often the most effective and equitable: tobacco taxation, minimum unit pricing for alcohol (Scotland 2018, Wales 2020), the Soft Drinks Industry Levy (2018) - led manufacturers to reduce sugar, restrictions on HFSS (high in fat, salt or sugar) product placement and advertising.

Models of Behaviour Change

• Transtheoretical (stages of change) model - Prochaska and DiClemente:

Stage	Description	Approach
Precontemplation	Not considering change	Raise awareness, provide information, keep the door open
Contemplation	Thinking about change, ambivalent	Motivational interviewing - explore pros and cons
Preparation	Planning to change soon	Help set a date and a plan; offer support and treatment
Action	Making the change	Support, pharmacotherapy, practical strategies
Maintenance	Sustaining change >6 months	Relapse prevention
Relapse	Return to old behaviour	Normal part of the cycle; re-engage without judgement

• Health Belief Model - action depends on perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action and self-efficacy.
• Theory of Planned Behaviour - intention depends on attitudes, subjective norms and perceived behavioural control.
• COM-B model (Michie) - Behaviour depends on Capability (physical and psychological), Opportunity (physical and social) and Motivation (reflective and automatic); part of the Behaviour Change Wheel used by NICE (NG183 Behaviour change).
• Motivational interviewing - a collaborative, person-centred style using OARS: Open questions, Affirmations, Reflective listening, Summaries; elicits "change talk"; rolls with resistance rather than confronting.
• SMART goals - Specific, Measurable, Achievable, Relevant, Time-bound.

Brief Interventions and MECC

• Very Brief Advice (VBA) on smoking - Ask, Advise, Act (30 seconds): record smoking status, advise that the best way to stop is with support and medication, and act by offering referral or prescription.
• Brief intervention (5–10 minutes) for alcohol - FRAMES: Feedback on risk, Responsibility of the individual, Advice to change, Menu of options, Empathy, Self-efficacy.
• Making Every Contact Count (MECC) - all health and care staff use routine contacts to encourage healthier behaviour (smoking, alcohol, weight, physical activity, mental wellbeing).
• Brief interventions work: physician advice to stop smoking increases quit rates; alcohol brief interventions reduce consumption by about 3–4 units a week on average.

Smoking and Vaping

• The leading preventable cause of death and illness - about 74,000 deaths a year in England; half of long-term smokers die from smoking; smokers lose on average about 10 years of life (stopping at 30 gains almost all of it back; stopping at 60 gains about 3 years).
• Prevalence in England is about 12% of adults, but much higher in routine and manual workers, people with serious mental illness (about 3 times higher), and in some deprived communities - smoking is a major driver of health inequalities.
• Diseases: lung and many other cancers (mouth, larynx, oesophagus, bladder, pancreas, kidney, cervix, stomach), COPD, IHD, stroke, PAD, AAA, osteoporosis, cataract, macular degeneration, erectile dysfunction, poor wound healing; in pregnancy - miscarriage, stillbirth, low birth weight, SIDS.
• Treatment (NICE NG209): behavioural support from stop smoking services plus pharmacotherapy roughly triples the chance of quitting compared with willpower alone.
  • Varenicline (partial nicotine receptor agonist) - the most effective single drug; start 1–2 weeks before the quit date; 12 weeks; nausea, vivid dreams; supply resumed in the UK after the 2021 nitrosamine recall.
  • Combination NRT (long-acting patch plus short-acting gum, lozenge, inhalator or spray) - as effective as varenicline; safe in cardiovascular disease and, with advice, in pregnancy.
  • Cytisine - a plant-derived partial agonist, licensed in the UK (2024).
  • Bupropion - less used; contraindicated in epilepsy and eating disorders.
  • Nicotine vapes (e-cigarettes) - substantially less harmful than smoking and effective quitting aids (Cochrane); recommended by NICE as an option for adults; not risk-free, and not for non-smokers or young people. Disposable vapes were banned in the UK from June 2025.
• Population measures: taxation, smoke-free public places (2007) and cars with children (2015), plain (standardised) packaging (2016), display bans, minimum age of sale, and the Tobacco and Vapes Bill (generational ban - people born on or after 1 January 2009 would never be legally sold tobacco).
• Very Brief Advice at every opportunity; carbon monoxide monitoring at antenatal booking with opt-out referral; smoking cessation for all hospital inpatients (the "Ottawa model").
• Medication interactions on stopping: smoking induces CYP1A2 - clozapine, olanzapine and theophylline levels rise when a patient stops smoking (reduce doses and monitor).

Alcohol

• UK Chief Medical Officers' low-risk guideline (2016): no more than 14 units a week for men and women, spread over 3 or more days, with several drink-free days; no "safe" level; no alcohol in pregnancy or when planning pregnancy.
• 1 unit = 10 mL (8 g) pure alcohol; units = volume (mL) × ABV (%) ÷ 1,000. A pint of 5% beer ≈ 2.8 units; a 175 mL glass of 12% wine = 2.1 units; a 750 mL bottle of 13% wine ≈ 9.8 units.
• Harms: liver disease (the commonest cause of death from alcohol), cancers (mouth, throat, oesophagus, breast, liver, bowel), hypertension, AF, cardiomyopathy, pancreatitis, injuries, violence, depression and suicide, Wernicke–Korsakoff syndrome, fetal alcohol spectrum disorder; about 10,000 alcohol-specific deaths a year in the UK, rising since 2020.
• Screening: AUDIT-C, then full AUDIT (8–15 increasing risk; 16–19 higher risk; ≥20 possible dependence) - see the GP mental health chapter for brief intervention and withdrawal.
• Population measures: price (minimum unit pricing - Scottish evaluation showed about a 13% reduction in alcohol-specific deaths), availability (licensing), marketing restrictions, drink-driving laws (limit 80 mg/100 mL blood in England and Wales; 50 mg/100 mL in Scotland).

Obesity, Diet and Nutrition

• BMI (kg/m²): healthy 18.5–24.9; overweight 25–29.9; obesity 30–39.9; severe obesity ≥40. Lower thresholds for South Asian, Chinese, other Asian, Middle Eastern, Black African or African–Caribbean origin (overweight ≥23; obesity ≥27.5).
• Waist-to-height ratio - keep waist less than half of height (0.5–0.59 increased risk; ≥0.6 high risk).
• Prevalence - about 26–29% of adults in England have obesity and about two-thirds are overweight or obese; at reception about 1 in 10 children have obesity, rising to about 1 in 5 by Year 6, with a steep deprivation gradient.
• Consequences: type 2 diabetes, hypertension, CVD, many cancers (obesity is the second biggest preventable cause of cancer), osteoarthritis, OSA, NAFLD/MASLD, PCOS, infertility, depression and stigma.
• Management (NICE NG246, 2025): multicomponent lifestyle interventions (diet, activity, behaviour change - tier 2); specialist weight management (tier 3); medicines - semaglutide and tirzepatide (NICE technology appraisals, criteria-based; tirzepatide rolled out in primary care in phases from 2025), orlistat; bariatric surgery (tier 4) for BMI ≥40, or 35–39.9 with significant comorbidity (lower thresholds for recent-onset type 2 diabetes).
• NHS Diabetes Prevention Programme (Healthier You) - for people with non-diabetic hyperglycaemia (HbA1c 42–47 mmol/mol); reduces progression to diabetes.
• Healthy eating: the Eatwell Guide - 5 portions of fruit and vegetables a day, starchy carbohydrates (wholegrain), 30 g fibre, 2 portions of fish a week (1 oily), less than 6 g salt a day, limit free sugars to 5% of energy, limit saturated fat and red/processed meat.
• Micronutrients: vitamin D 10 micrograms daily (everyone in autumn and winter; all year for at-risk groups; Healthy Start vitamins for children 6 months–5 years), folic acid before pregnancy (folic acid fortification of non-wholemeal wheat flour is being introduced in the UK).
• Undernutrition - MUST screening (BMI, weight loss, acute illness); common in older people, hospital inpatients and people with cancer.

Physical Activity and Sedentary Behaviour

• UK CMO guidelines (2019) - adults: at least 150 minutes of moderate or 75 minutes of vigorous activity a week (or a combination), muscle-strengthening on at least 2 days, and minimise prolonged sitting; older adults - add balance and flexibility activities to reduce falls.
• Children and young people (5–18): an average of 60 minutes of moderate-to-vigorous activity a day; under-5s - 180 minutes a day of activity (including 60 minutes moderate-to-vigorous for 3–4-year-olds).
• Benefits: reduces all-cause mortality by about 30%, plus CVD, type 2 diabetes, several cancers (bowel, breast), depression, dementia, falls and fractures. Physical inactivity causes about 1 in 6 deaths in the UK.
• Interventions: brief advice using the General Practice Physical Activity Questionnaire (GPPAQ), exercise referral schemes, social prescribing, active travel (walking and cycling), urban design, park runs.

Sexual Health and Teenage Pregnancy

• STIs - highest rates in young people (15–24) and gay, bisexual and other men who have sex with men; gonorrhoea and syphilis diagnoses have risen to the highest levels for many decades.
• National Chlamydia Screening Programme - since 2021 focused on young women aged 15–24 (opportunistic testing with annual retesting and on change of partner), to reduce reproductive harm.
• HIV prevention - condoms, PrEP (routinely available through sexual health clinics), PEP, testing (opt-out testing in emergency departments in very high-prevalence areas), and U=U (undetectable = untransmittable - people with an undetectable viral load on treatment do not transmit HIV sexually). England aims to end new HIV transmissions by 2030.
• Teenage pregnancy - England's under-18 conception rate has fallen by more than two-thirds since 1998 (Teenage Pregnancy Strategy: sex and relationships education, access to contraception - especially LARC).
• Vaccination: HPV (adolescents; MSM up to 45 through sexual health clinics), hepatitis A and B for MSM, mpox vaccination for those at higher risk, and the 4CMenB vaccine for gonorrhoea prevention offered to those at highest risk (programme from 2025).

Drugs and Gambling

• Drug misuse - drug poisoning deaths in England and Wales are at their highest since records began (more than 5,000 a year), mostly opioid-related and increasingly involving synthetic opioids (nitazenes) and polysubstance use; Scotland has one of the highest drug death rates in Europe.
• Harm reduction: opioid substitution therapy (methadone, buprenorphine - including long-acting injectable buprenorphine), needle and syringe programmes, take-home naloxone, hepatitis C test and treat (England aims to eliminate hepatitis C as a public health threat), drug checking, and the first overdose prevention centre (Glasgow, 2025).
• Gambling harm - now recognised as a public health issue; NHS gambling clinics; screening with the Problem Gambling Severity Index (PGSI).

Mental Health Promotion and Suicide Prevention

• Five Ways to Wellbeing - connect, be active, take notice, keep learning, give.
• About 6,000 suicides a year in the UK - three-quarters are male; the highest rates are in middle-aged men; about a quarter of people who die by suicide have been in contact with mental health services in the previous year.
• Suicide Prevention Strategy for England (2023) - priority groups include middle-aged men, people who have self-harmed, children and young people, people in contact with the justice system, autistic people, pregnant and new mothers; actions include means restriction (e.g. limiting paracetamol pack sizes - reduced deaths after 1998, barriers at high-risk locations), responsible media reporting, bereavement support and crisis support (NHS 111 option 2).
• Perinatal mental health - suicide is a leading cause of maternal death in the year after birth (MBRRACE-UK).

Oral Health and Water Fluoridation

• Tooth decay is the commonest reason for hospital admission in children aged 6–10 in England (for extractions under general anaesthetic), with a strong deprivation gradient.
• Prevention: fluoride toothpaste (1,000 ppm for under-3s as a smear; 1,350–1,500 ppm from age 3 as a pea-sized amount), spit don't rinse, brushing twice daily, reducing sugary drinks and snacks, fluoride varnish, supervised toothbrushing in nurseries.
• Water fluoridation - about 10% of England's population receives fluoridated water; the Health and Care Act 2022 gave the Secretary of State powers to extend schemes. Evidence shows reduced caries, particularly in deprived areas; mild dental fluorosis is the main adverse effect.

Injury Prevention

• Road traffic injuries - seatbelt laws (1983), drink-driving limits, 20 mph zones, speed cameras, helmets, child car seats.
• Falls in older people - strength and balance programmes (see the Geriatric Medicine chapters).
• Childhood injuries - home safety equipment (stair gates, window restrictors, smoke alarms), safe storage of medicines, water safety, button battery and magnet ingestion awareness.
• Haddon's matrix - analyses injury by host, agent and environment factors before, during and after the event.

Prevention at a Glance

Risk factor	Key number	Most effective individual intervention	Population measure
Smoking	~12% adults; ~74,000 deaths/year (England)	Behavioural support + varenicline or combination NRT (or vapes)	Tax, smoke-free laws, plain packs, generational ban
Alcohol	14 units/week	Brief intervention (FRAMES)	Minimum unit pricing
Obesity	BMI ≥30 (≥27.5 some ethnic groups)	Multicomponent programmes; GLP-1 medicines; surgery	Sugar levy, HFSS restrictions
Activity	150 min moderate + strength 2 days	Brief advice; exercise referral	Active travel, urban design
Diet	5-a-day; <6 g salt; 30 g fibre	Dietary advice	Salt reformulation, fortification

Spot the Answer

• A smoker says she enjoys smoking and has no plans to stop. → Precontemplation - give very brief advice and keep the door open.
• A man drinks four 175 mL glasses of 12% wine every night. → About 8.4 units/day, 59 units/week - AUDIT, brief intervention, assess for dependence.
• A patient on clozapine stops smoking and becomes drowsy and confused. → Clozapine toxicity - smoking cessation removes CYP1A2 induction; check levels and reduce the dose.
• Taxing sugary drinks so that manufacturers reformulate. → Population measure (fiscal; Soft Drinks Industry Levy).
• A South Asian man with BMI 28. → Meets the obesity threshold for his ethnic group (≥27.5).

Exam-style Scenarios

• Scenario. A 45-year-old with type 2 diabetes smokes 20 a day and says he has tried "everything" to stop.
  Answer: Explore previous attempts and what helped (COM-B: capability, opportunity, motivation). Offer referral to stop smoking services with varenicline or combination NRT (or a nicotine vape) and set a quit date. Relapse is normal - most people need several attempts.
• Scenario. A 16-year-old asks about vaping because "it's safe".
  Answer: Vapes are much less harmful than smoking, but they are not risk-free; nicotine is addictive and vaping is not recommended for non-smokers or young people. If she smokes, vaping may help her stop; if she does not smoke, advise against starting.
• Scenario. A director of public health has funding for one intervention to reduce alcohol harm. Which has the strongest evidence for population impact?
  Answer: Price-based measures (minimum unit pricing, taxation) and restricting availability and marketing have the strongest evidence of population benefit (WHO "best buys"), especially for the heaviest drinkers and most deprived groups. Brief interventions are effective for individuals.

Key Points

• Smoking remains the biggest preventable cause of death and a major driver of inequalities.
• Combination NRT, varenicline and vapes with behavioural support are the most effective quitting aids.
• 14 units a week maximum; no alcohol in pregnancy.
• BMI thresholds are lower for many ethnic minority groups.
• 150 minutes of moderate activity plus strength exercises twice a week.
• Population measures (price, availability, marketing, reformulation) usually achieve the largest and most equitable effects.

Guidelines and Further Reading

• NICE NG209: Tobacco - preventing uptake, promoting quitting and treating dependence
• NICE NG183: Behaviour change - digital and mobile health interventions; NICE PH49 (individual approaches to behaviour change)
• UK Chief Medical Officers: Low risk drinking guidelines (2016); Physical activity guidelines (2019)
• NICE NG246: Overweight and obesity management (2025)
• Public Health England / OHID: The Eatwell Guide
• Department of Health and Social Care: Suicide prevention strategy for England (2023)
• Michie S et al. The behaviour change wheel (2011)
• Cochrane review: Electronic cigarettes for smoking cessation (updated regularly)