Understanding long-term trends in smoking in England, 1972-2019: an age-period-cohort approach.

Background and Aims: Smoking prevalence has been falling in England for more than 50 years, but remains a prevalent and major public health problem. This study used an age-period-cohort (APC) approach to measure lifecycle, historical and generational patterns of individual smoking behaviour.
Design: APC analysis of repeated cross-sectional smoking prevalence data obtained from three nationally representative surveys.
Setting: England (1972-2019).
Participants: Individuals aged 18-90 years.
Measurements: We studied relative odds of current smoking in relation to age in single years from 18 to 90, 24 groups of 2-year survey periods (1972-73 to 2018-19) and 20 groups of 5-year birth cohorts (1907-11 to 1997-2001). Age and period rates were studied for two groups of birth cohorts: those aged 18-25 years and those aged over 25 years.
Findings: Relative to age 18, the odds of current smoking increased with age until approximately age 25 [odds ratio (OR) = 1.48, 95% confidence interval (CI) = 1.41-1.56] and then decreased progressively to age 90 (OR = 0.06, 95% CI = 0.04-0.08). They also decreased almost linearly with period relative to 1972-73 (for 2018-19: OR = 0.30, 95% CI = 0.26-0.34) and with birth cohort relative to 1902-06, with the largest decreased observed for birth cohort 1992-96 (OR = 0.44, 95% CI = 0.35-0.46) and 1997-2001 (OR = 0.35, 95% CI = 0.74-0.88). Smoking declined in the 18-25 age group by an average of 7% over successive 2-year periods and by an average of 5% in those aged over 25.
Conclusions: Smoking in England appears to have declined over recent decades mainly as a result of reduced smoking uptake before age 25, and to a lesser extent to smoking cessation after age 25.
(© 2021 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)