title: The health indicators associated with screen-based sedentary behavior among adolescent girls: a systematic review.
abstract: OBJECTIVE
  Evidence suggests sitting time is independently associated with a range of health issues in adults, yet the relationship between sedentary behavior and health indicators in young people is less clear. Age-related increases in sedentary behavior are well-documented; the behavioral patterns of adolescent girls are of particular concern. More than one third of adolescent girls' sedentary behavior time is accumulated through use of recreational screen-based behaviors. The objective of this review was to investigate the association between recreational screen-based sedentary behavior and the physical, behavioral, and psychosocial health indicators for adolescent girls. A secondary objective was to identify studies that have adjusted sedentary behavior indicators for physical activity.
  
  
  METHODS
  A structured electronic search of all publication years (through December 2011) was conducted to identify studies in: CINAHL, Communications and Mass Media Complete, ERIC, MEDLINE with Full Text, PsycINFO, and SPORTDiscus with Full Text. Included publications were observational and interventional studies involving adolescent girls (12-18 years) that examined associations between screen-based, sedentary behavior and health indicators (physical, psychosocial, and/or behavioral). The search identified 33 studies that evaluated health indicators of screen-based sedentary behaviors among adolescent girls.
  
  
  RESULTS
  Strong evidence for a positive association between screen-based sedentary behavior and weight status was found. A positive association was observed between screen-time and sleep problems, musculoskeletal pain and depression. Negative associations were identified between screen time and physical activity/fitness, screen time and psychological well-being, and screen time and social support. The relationship between screen-based sedentary behavior and diet quality was inconclusive. Less than half of the studies adjusted sedentary behavior indicators for physical activity.
  
  
  CONCLUSIONS
  Screen-based sedentary behavior is associated with a range of adverse health consequences, but additional longitudinal studies are needed to better understand the health impacts. In addition, screen-time guidelines for youth should be regularly revised and updated to reflect rapid technological changes.
authors.affiliation: Priority Research Centre in Physical Activity and Nutrition, School of Education, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Costigan
authors.forename: Lisa
authors.initials: L
authors.lastname: Barnett
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Plotnikoff
authors.forename: David R
authors.initials: DR
authors.lastname: Lubans
mesh_terms: D000293:Adolescent; D005260:Female; D062489:Health Impact Assessment; D006305:Health Status Indicators; D006801:Humans; D007899:Leisure Activities; D008838:Microcomputers; D009043:Motor Activity; D057185:Sedentary Behavior; D013223:Statistics as Topic; D013690:Television