Definition of terms used to describe patient age information in the ACR Appropriateness Criteria® topics.
Neonate – Birth to one month old1
Infant – Birth to one year old2
Child – Birth to 18 years old, unless otherwise specified3
Adolescent – A transitional stage of physical development occurring between puberty and adulthood4
Adult – Greater than 18 years old, unless otherwise specified
1Merriam-Webster Dictionary. http://www.merriam-webster.com/dictionary/neonate. Accessed March 21, 2011.
2World Population Prospects: The 2008 Revison Population Database. http://esa.un.org/unpp/index.asp?panel=7. Accessed March 21, 2011.
3Convention on the Rights of the Child. UNICEF publications. http://www.unicef.org/crc/index_30227.html. Accessed March 21, 2011.4Christie D, Viner R. Adolescent development. BMJ. 2005;330(7486):301-304.