The Australian epidemic of cardiovascular mortality 1935–2005: effects of period and birth cohort
- 1School of Public Health and Community Medicine, University of New South Wales, Randwick, New South Wales, Australia
- 2School of Population Health, University of Queensland, Herston, Queensland, Australia
- Correspondence to Professor Richard Taylor, School of Public Health and Community Medicine, Faculty of Medicine, University of New South Wales Main Campus, Samuels Building, Level 2, Room 223, Botany Street, Gate 11, Randwick (Sydney), NSW 2052, Australia;
- Accepted 9 December 2010
- Published Online First 30 January 2011
Background This study investigates the period and birth cohort effects in cardiovascular disease (CVD) mortality in Australia, and assesses explanations related to contemporaneous effects of changes in risk factors (period effects) and influences of exposures earlier in life (cohort effects).
Methods Australian mortality from diseases of the circulatory system (DoCS; International Classification of Diseases (ICD) 9th revision, chapter 7), were investigated by sex and 5-year age group (35–79 years) from 1935 to 2005 for: all DoCS, all DoCS less rheumatic heart disease (RHD) and stroke. Ischaemic heart disease (IHD; ICD9 410–4) trends from 1968 were also examined. The extent to which the Australian CVD epidemic was characterised by period effects or birth cohort effects was investigated by age and cohort-specific analyses of secular trends, and age–period–cohort (APC) models.
Results The CVD epidemic increased into the 1960s, with men one third higher than women, predominantly due to IHD. A sustained decline occurred in both sexes from 1970. Deduction of RHD from CVD steepened the ascent of the epidemic. Age-specific analyses of CVD mortality (less RHD) by period and cohort, and APC modelling, indicate that the rise and fall of the epidemic are period effects.
Conclusion The period epidemic of CVD mortality in Australia 1935–2005, consistent with international reports, supports the concurrent effects of changes in risk factors in adults on CVD mortality, and does not support effects of differential exposures by birth cohort, as would occur with changes in perinatal influences such as birth weight. Prevention of CVD mortality should focus on lowering risk factors in adults.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.