50-year mortality trends in children and young people: a study of 50 low-income, middle-income, and high-income countries

Abstract

Background: Global attention has focused on mortality in children younger than 5 years. We analysed global mortality data for people aged 1-24 years across a 50-year period.

Methods: The WHO mortality database was used to obtain mortality data from 1955 to 2004, by age-group (1-4, 5-9, 10-14, 15-19, and 20-24 years) and stratified by sex. To analyse change in mortality, we calculated mortality rates averaged over three 5-year periods (1955-59, 1978-82, and 2000-04) to investigate trends in deaths caused by communicable and non-communicable diseases and injury.

Findings: Data were available for 50 countries (ten high income, 22 middle income, eight low income, seven very low income, and three unclassified), grouped as Organisation for Economic Co-operation and Development (OECD) countries, Central and South American countries, eastern European countries and ex-Soviet states, and other countries. In 1955, mortality was highest in the 1-4-year age-group. Across the study period, all-cause mortality reduced by 85-93% in children aged 1-4 years, 80-87% in children aged 5-9 years, and 68-78% in young people aged 10-14 years in OECD, Central and South American, and other countries. Smaller declines (41-48%) were recorded in young men (15-24 years), and by 2000-04, mortality in this group was two-to-three times higher than that in young boys (1-4 years). Mortality in young women (15-24 years) was equal to that of young girls (1-4 years) from 2000 onwards. Substantial declines in death caused by communicable diseases were seen in all age-groups and regions, although communicable and non-communicable diseases remained the main causes of death in children (1-9 years) and young women (10-24 years). Injury was the dominant cause of death in young men (10-24 years) in all regions by the late 1970s.

Interpretation: Adolescents and young adults have benefited from the epidemiological transition less than children have, with a reversal of traditional mortality patterns over the past 50 years. Future global health targets should include a focus on the health problems of people aged 10-24 years.

Funding: None.