title: Mortality in Children Aged 0-9 Years: A Nationwide Cohort Study from Three Nordic Countries.
abstract: BACKGROUND
  Mortality in children under five years has been widely studied, whereas mortality at 5-9 years has received little attention. Using unique data from national registers in three Nordic countries, we aimed to characterize mortality directionality in children aged 0 to 9 years.
  
  
  RESULTS
  The cohort study included all children born in Denmark from 1973 to 2008 (n = 2,433,758), Sweden from 1973 to 2006 (n = 3,400,212), and a random sample of 89.3% of children born in Finland from 1987 to 2007 (n = 1,272,083). Children were followed from 0 to 9 years, and cumulative mortality and mortality rates were compared by age, gender, cause of death, and calendar periods. Among the 7,105,962 children, there were 48,299 deaths during study period. From 1981-1985 to 2001-2005, all-cause mortality rates were reduced by between 34% and 62% at different ages. Overall mortality rate ratio between boys and girls decreased from 1.25 to 1.21 with the most prominent reduction in children aged 5-9 years (from 1.59 to 1.19). Neoplasms, diseases of the nervous system and transport accidents were the most frequent cause of death after the first year of life. These three leading causes of death declined by 42% (from 6.2 to 3.6 per 100,000 person years), 43% (from 3.7 to 2.1) and 62% (from 3.9 to 1.5) in boys, and 25% (from 4.1 to 3.1 per 100000 person years), 42% (from 3.4 to 1.9) and 63% (from 3.0 to 1.1) in girls, respectively. Mortality from neoplasms was the highest in each age except infants when comparing cause-specific mortality, and half of deaths from diseases of the nervous system occurred in infancy. Mortality rate due to transport accidents increased with age and was highest in boys aged 5-9 years.
  
  
  CONCLUSIONS
  Mortality rate in children aged 0-9 years has been decreasing with diminished difference between genders over the past decades. Our results suggest the importance of further research on mortality by causes of neoplasms, and causes of transport accidents-especially in children aged 5-9 years.
authors.affiliation: Section for Epidemiology, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Biostatistics, School of Public Health, Fudan University, Shanghai, China.
authors.forename: Guoyou
authors.initials: G
authors.lastname: Qin
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska University Hospital, Karolinska Institute, Stockholm, Sweden.
authors.forename: Sven
authors.initials: S
authors.lastname: Cnattingius
authors.affiliation: Information Department, THL National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Mika
authors.initials: M
authors.lastname: Gissler
authors.affiliation: Department of Epidemiology, School of Public Health, University of California Los Angeles, Los Angeles, California, United States of America.|Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.affiliation: Department of Biostatistics, School of Public Health, Fudan University, Shanghai, China.
authors.forename: Naiqing
authors.initials: N
authors.lastname: Zhao
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jiong
authors.initials: J
authors.lastname: Li
mesh_terms: D000063:Accidents, Traffic / Q000401:mortality*; D002648:Child; D046688:Child Mortality; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D009369:Neoplasms / Q000401:mortality*; D013548:Sweden / Q000453:epidemiology