title: Explaining socio-demographic differences in disengagement from sports in adolescence.
abstract: OBJECTIVE
  The purpose of this longitudinal study is to identify risk groups for disengagement from sports during adolescence. In addition, it will be explored whether cognitive and environmental factors can explain socio-demographic differences in disengagement from sports.
  
  
  METHODS
  Data were obtained from the Environmental Determinants of Obesity in Rotterdam Schoolchildren study, and 357 adolescents were eligible for analysis. Socio-demographics (gender, ethnicity, education), individual cognitions and neighbourhood perceptions were assessed at baseline (2005/2006), and sports participation at baseline and at follow-up (2007/2008). Two dichotomous outcome variables were constructed: (i) disengagement from sports (yes/no) and (ii) ceased compliance with the fitnorm (i.e. cease engaging in sports ≥3 times/wk) (yes/no). In logistic regression and mediation analyses, we identified socio-demographic differences in the two outcomes. Subsequently, we applied mediation analyses to identify the contribution of cognitive and environmental explanatory factors of the socio-demographic differences.
  
  
  RESULTS
  Girls [odds ratio (OR): 2.5, 95% confidence interval (CI): 1.5-4.5] were more likely than boys to disengage from sports. Girls (OR: 2.5, 95% CI: 1.4-4.2), adolescents of non-Western background (OR: 1.8, 95% CI: 1.0-3.0) and those in lower educational levels (OR: 1.7, 95% CI: 1.0-2.9) were more likely to cease compliance with the fitnorm. Perceived neighbourhood safety partly explained gender differences in disengagement from sports (8%). Intention partly explained ethnical (32%) and educational differences (37%) in ceasing compliance with the fitnorm.
  
  
  CONCLUSIONS
  Girls, lower-educated adolescents and those with a non-Western background showed more pronounced reductions in sports participation and compliance with the fitnorm. Intention and perceived neighbourhood safety could partially explain these differences.
authors.affiliation: 1 Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Prins
authors.forename: Carlijn B M
authors.initials: CB
authors.lastname: Kamphuis
authors.forename: Pepijn
authors.initials: P
authors.lastname: van Empelen
authors.forename: Mariëlle A
authors.initials: MA
authors.lastname: Beenackers
authors.forename: Johannes
authors.initials: J
authors.lastname: Brug
authors.forename: Johan P
authors.initials: JP
authors.lastname: Mackenbach
authors.forename: Anke
authors.initials: A
authors.lastname: Oenema
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D003710:Demography; D004522:Educational Status; D005006:Ethnicity; D005260:Female; D015438:Health Behavior; D006801:Humans; D033182:Intention; D008137:Longitudinal Studies; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D012111:Residence Characteristics / Q000145:classification; D012449:Safety; D057566:Self Report; D012737:Sex Factors; D012959:Socioeconomic Factors; D013177:Sports / Q000523:psychology*