Skip to main content

Table 1 Illustrates the variable definitions used and overlap of different age groups of children

From: Children and adolescents presenting to chiropractors in Norway: National Health Insurance data and a detailed survey

Name Definition
Preterm neonate Period at birth when a newborn is born before full gestational period.
Term Neonate Birth to 27 days.
Newborn up to 1 month.
A newborn infant, or neonate, is a child under 28 days of age.
Infant/Infancy 28 days to 1 year of age.
1 month to 2 years.
0 to 1 year of age.
Toddler 13 months to 2 years.
1 to 3 years.
Preschool child 3 to 5 years.
Early childhood 2 to 5 years.
Middle childhood 6 to 11 years.
Child 2 to 12 years.
Young teen 12 to 14 years.
Teenager 15 to 17 years.
Adolescent 12 to 16 years.
10 to 19 years.
Early adolescence 12 to 18 years.
Late adolescence 19 to 21 years.
  2. a NICHD Eunice Kennedy Shriver National Institute of Child Health and Human Development
  3. b FDA US Food and Drug Administration
  4. c WHO World Health Organisation
  5. d CDC Centers for Disease Control and Prevention