Trends in young-adult mortality between the 1990s and the 2000s in urban and non-urban areas in Belgium: The role of a changing educational composition in overall mortality decline

This study probes into the evolution in young-adult mortality according to urbanisation degree in Belgium and moves beyond mere description through decomposing mortality trends into changes in educational distribution and in overall mortality. As most of young-adult deaths are preventable and an enormous cost and loss to society, this study addresses a highly relevant public-health topic. Individual record-linked data between the Belgian censuses of 1991 and 2001 and register data on death and emigrations are used. Age-standardized mortality rates (ASMR), directly standardized to the European Population of 2013 are calculated with 95% confidence intervals (CI), as well as a decomposition measure to pinpoint the proportion mortality change attributable to differences in educational composition over time. The young-adult population consists of 2,458,637 19-34 year-olds in 1991, with 11,898 deaths in a five-year period, and is slightly smaller in 2001 with 2,174,368 young adults and 8138 deaths. Overall, there is a positive evolution towards lower young-adult mortality, with the strongest declines in men living in large urban areas (ASMR from 149.0 [CI 142.1-155.8] in 1991-1996 to 94.6 [88.9-100.3] in 2001-2006). Decomposition analysis shows that the decrease in male mortality in non-urban areas over time is largely due to changes in the educational composition, while mortality in urban areas mainly decreases because of a decline in overall mortality. In urban areas all educational groups have benefitted over time. This clearly demonstrates that living and growing up in an urban area does not always have to imply a health penalty, but can have health advantages as well.