Prevalence of Smoking (DP IB Psychology): Revision Note

Prevalence of smoking worldwide

• Prevalence rates show how common a disorder or behaviour (e.g., smoking) is within a specific population in a given time period

• It may be reported as a percentage (e.g., 5%) or as the number of cases per 10,000 or 100,000 people

Types of prevalence

• There are different ways to report prevalence depending on the timeframe of the estimate:

  • Point prevalence – the proportion of a population smoking at a specific point in time

  • Period prevalence – the proportion smoking at any time during a set period (e.g., past 12 months)

  • Lifetime prevalence – the proportion who have smoked at any point in their life

WHO data (2024)

• The World Health Organization (WHO, 2024) collects data on tobacco use:

  • In 2022, 20.9% of the world’s population aged 15+ smoked cigarettes

  • Around 80% of the 1.25 billion tobacco users live in low- and middle-income countries

  • The global prevalence of smoking is declining each year, but some countries (e.g., Egypt, Jordan, Indonesia) show rising rates among men (Reuters, 2024)

Prevalence of smoking: age & gender

Gender

• In 2022, 34.4% of men and 7.4% of women used tobacco

• In 2000, about 16.3% of women (aged 15+) used tobacco

• Male-to-female ratio has widened:

  • In 2000 men were 3 times more likely to smoke

  • In 2022 men were 4 times more likely to smoke

  • Projected figures show that in 2030 men will be 5 times more likely to smoke

• The decline in female smoking is faster than in males, but varies by region:

  • South-East Asia: highest female prevalence in 2000 (33%) reduced to 10% in 2022

  • Europe now has the highest female prevalence (18% in 2022); the decline is slower than Asia

Age

• 15–23 years: Approximately 13% use tobacco

• 45–54 years: The highest prevalence overall (18–28%)

• 85+ years: Approximately 13% use tobacco

• After 54 years, prevalence declines as smokers age, reflecting health impacts and mortality among long-term users

Research support for prevalence of smoking

Valente et al. (2005)

Aim: 

• To investigate whether popular students are more likely to start smoking

Participants:

• 1,486 students (aged 12-14, grades 6-7) from 16 middle schools in southern California

Procedure: 

• Three surveys were administered to students, consisting of: 

  • a baseline survey, measuring gender, ethnicity, age, grades, susceptibility to smoke, and smoking behaviour

  • a survey two months later, measuring social networks 

  • a 1-year follow-up survey 

• Susceptibility to smoke was measured as a refusal to commit to never smoking in the future

• Smoking was defined as 'ever puffed or smoked a cigarette'

• Popularity was defined as the number of times chosen as a friend by others

Results:

• Popular students were 5 times more likely to smoke than average students

• Unpopular/isolated students were also more likely to be susceptible to or had already started smoking

Conclusion:

• Popular students influence social norms: when they smoke, peers see it as acceptable or desirable

• Because popular students are more socially connected, their influence on smoking behaviour spreads more widely

Evaluation of prevalence of smoking

Strengths

• Understanding prevalence is vital due to the serious health risks of nicotine addiction

• Valente’s study highlights the importance of early intervention in adolescence to reduce smoking rates

Limitations

• Knowing prevalence rates is not enough — governments face challenges in implementing effective interventions

• Prevalence data is descriptive, not explanatory — it does not reveal why people smoke

  • Smoking behaviour is complex; more qualitative research is needed to explore cultural, social, and psychological causes

Link to concepts

Change

• Research shows that smoking decreases with age, which may reflect the development of health problems associated with smoking, e.g., breathing difficulties and lung and heart disease

• Quitting smoking may also be a result of starting a family and not wishing to expose children to harmful tobacco smoke

• Social changes (e.g., smoking bans in several countries) and increased awareness of the dangers of smoking may have contributed to prevalence rates falling

Causality

• Prevalence rates can only show what is happening; they cannot explain why it is happening, which means that researchers can only infer the reasons behind a decrease in prevalence rates for smoking

• There is no real way to establish cause-effect (e.g., health promotion campaigns and people quitting smoking); it is only possible to point to a relationship between certain factors and a fall in smoking prevalence generally