The new findings show that, since 1970, child and youth death rates have fallen significantly more slowly in the UK than in 17 other nations in the European Union, Australia, Canada and Norway.
Although young people aged ten to 24 had an average likelihood of death comparable with that of the other countries, this masked poor progress in tackling deaths from non-communicable diseases (NCDs) – chronic diseases that are not passed from person to person.
Britain’s record for infants younger than a year old and children aged one to nine was said to be especially poor.
By 2008, an estimated 1,035 more infant deaths occurred each year in the UK than in the group of nations as a whole.
Worsening NCD trends had cancelled out the benefits of the UK’s good record for injury-related deaths.
Lead researcher Professor Russell Viner, from University College London, said: “Fewer children survive and thrive in countries with wide inequalities, such as the UK.
“We urgently need to understand more about the role that is played in causing the mortality excess by social factors, such as higher inequality in Britain than most of Europe, and by differences in our healthcare system.”
NCDs were responsible for around three-quarters of UK deaths of children aged one to nine, and half of all deaths of young people aged ten to 24.
Prof Viner and colleagues analysed patterns and causes of death among children and young people in the UK compared with a group of similar, wealthy countries between 1970 and 2008.
The UK has remained in the best 25 per cent over the past 38 years for most age groups only for injury-related deaths.
Co-author Dr Ingrid Wolfe, of Kings College London, said: “There are no simple explanations for the UK’s worsening relative performance, and equally no simple solutions.
“However, our findings show that the growing contribution of NCDs to deaths among children and young people in the UK – around 75 per cent of deaths in children aged one to nine years old and half of all deaths in young people aged ten to 24 – will require a new focus.”
Commenting on the findings, paediatric specialist Dr Brian Johnston, of the University of Washington in the US, said the onus for closing the performance gap should not be placed solely on the healthcare sector.
He said: “A parsimonious explanation for the UK’s disappointing performance is that structural risks – the social determinants of health such as income, income inequality, access to care – are the cause of a substantial proportion of the excess death.”
The study was reported in The Lancet medical journal, which published other findings showing that children were more likely to die by the age of five in the UK than anywhere else in western Europe except Malta.