title: ROC generated thresholds for field-assessed aerobic fitness related to body size and cardiometabolic risk in schoolchildren.
abstract: OBJECTIVE
  1. to investigate whether 20 m multi-stage shuttle run performance (20mSRT), an indirect measure of aerobic fitness, could discriminate between healthy and overweight status in 9-10.9 yr old schoolchildren using Receiver Operating Characteristic (ROC) analysis; 2. Investigate if cardiometabolic risk differed by aerobic fitness group by applying the ROC cut point to a second, cross-sectional cohort.
  
  
  METHODS
  Analysis of cross-sectional data.
  
  
  METHODS
  16,619 9-10.9 year old participants from SportsLinx project and 300 11-13.9 year old participants from the Welsh Schools Health and Fitness Study.
  
  
  METHODS
  SportsLinx; 20mSRT, body mass index (BMI), waist circumference, subscapular and superilliac skinfold thicknesses. Welsh Schools Health and Fitness Study; 20mSRT performance, waist circumference, and clustered cardiometabolic risk.
  
  
  METHODS
  Three ROC curve analyses were completed, each using 20mSRT performance with ROC curve 1 related to BMI, curve 2 was related to waist circumference and 3 was related to skinfolds (estimated % body fat). These were repeated for both girls and boys. The mean of the three aerobic fitness thresholds was retained for analysis. The thresholds were subsequently applied to clustered cardiometabolic risk data from the Welsh Schools study to assess whether risk differed by aerobic fitness group.
  
  
  RESULTS
  The diagnostic accuracy of the ROC generated thresholds was higher than would be expected by chance (all models AUC >0.7). The mean thresholds were 33 and 25 shuttles for boys and girls respectively. Participants classified as 'fit' had significantly lower cardiometabolic risk scores in comparison to those classed as unfit (p<0.001).
  
  
  CONCLUSIONS
  The use of the ROC generated cut points by health professionals, teachers and coaches may provide the opportunity to apply population level 'risk identification and stratification' processes and plan for "at-risk" children to be referred onto intervention services.
authors.affiliation: The Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Boddy
authors.forename: Non E
authors.initials: NE
authors.lastname: Thomas
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Fairclough
authors.forename: Keith
authors.initials: K
authors.lastname: Tolfrey
authors.forename: Sinead
authors.initials: S
authors.lastname: Brophy
authors.forename: Anwen
authors.initials: A
authors.lastname: Rees
authors.forename: Gareth
authors.initials: G
authors.lastname: Knox
authors.forename: Julien S
authors.initials: JS
authors.lastname: Baker
authors.forename: Gareth
authors.initials: G
authors.lastname: Stratton
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control; D002648:Child; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008659:Metabolic Diseases / Q000209:etiology / Q000517:prevention & control; D050177:Overweight / Q000150:complications / Q000503:physiopathology; D010809:Physical Fitness; D012372:ROC Curve; D018570:Risk Assessment