title: The study design and methodology for the ARCHER study--adolescent rural cohort study of hormones, health, education, environments and relationships.
abstract: BACKGROUND
  Adolescence is characterized by marked psychosocial, behavioural and biological changes and represents a critical life transition through which adult health and well-being are established. Substantial research confirms the role of psycho-social and environmental influences on this transition, but objective research examining the role of puberty hormones, testosterone in males and oestradiol in females (as biomarkers of puberty) on adolescent events is lacking. Neither has the tempo of puberty, the time from onset to completion of puberty within an individual been studied, nor the interaction between age of onset and tempo. This study has been designed to provide evidence on the relationship between reproductive hormones and the tempo of their rise to adult levels, and adolescent behaviour, health and wellbeing.
  
  
  METHODS
  The ARCHER study is a multidisciplinary, prospective, longitudinal cohort study in 400 adolescents to be conducted in two centres in regional Australia in the State of New South Wales. The overall aim is to determine how changes over time in puberty hormones independently affect the study endpoints which describe universal and risk behaviours, mental health and physical status in adolescents. Recruitment will commence in school grades 5, 6 and 7 (10-12 years of age). Data collection includes participant and parent questionnaires, anthropometry, blood and urine collection and geocoding. Data analysis will include testing the reliability and validity of the chosen measures of puberty for subsequent statistical modeling to assess the impact over time of tempo and onset of puberty (and their interaction) and mean-level repeated measures analyses to explore for significant upward and downward shifts on target outcomes as a function of main effects.
  
  
  CONCLUSIONS
  The strengths of this study include enrollment starting in the earliest stages of puberty, the use of frequent urine samples in addition to annual blood samples to measure puberty hormones, and the simultaneous use of parental questionnaires.
authors.affiliation: Academic Department of Adolescent Medicine, University of Sydney, at Children's Hospital, Westmead, Sydney NSW 2145, Australia. kate.steinbeck@health.nsw.gov.au
authors.forename: Katharine
authors.initials: K
authors.lastname: Steinbeck
authors.forename: Philip
authors.initials: P
authors.lastname: Hazell
authors.forename: Robert G
authors.initials: RG
authors.lastname: Cumming
authors.forename: S Rachel
authors.initials: SR
authors.lastname: Skinner
authors.forename: Rebecca
authors.initials: R
authors.lastname: Ivers
authors.forename: Robert
authors.initials: R
authors.lastname: Booy
authors.forename: Greg
authors.initials: G
authors.lastname: Fulcher
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Martin
authors.forename: Geoff
authors.initials: G
authors.lastname: Morgan
authors.forename: Jean
authors.initials: J
authors.lastname: Starling
authors.forename: Adrian
authors.initials: A
authors.lastname: Bauman
authors.forename: Margot L
authors.initials: ML
authors.lastname: Rawsthorne
authors.forename: David L
authors.initials: DL
authors.lastname: Bennett
authors.forename: Chin Moi
authors.initials: CM
authors.lastname: Chow
authors.forename: Mary K
authors.initials: MK
authors.lastname: Lam
authors.forename: Patrick
authors.initials: P
authors.lastname: Kelly
authors.forename: Ngiare J
authors.initials: NJ
authors.lastname: Brown
authors.forename: Karen
authors.initials: K
authors.lastname: Paxton
authors.forename: Catherine
authors.initials: C
authors.lastname: Hawke
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D002648:Child; D015331:Cohort Studies; D004522:Educational Status; D004777:Environment; D004958:Estradiol / Q000097:blood*; D005260:Female; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D011627:Puberty; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D004958:Estradiol