title: Cross-validation of pedometer-determined cut-points for healthy weight in British children from White and South Asian backgrounds.
abstract: BACKGROUND
  Evidence-based pedometer cut-points for health have not been sufficiently examined in the context of ethnicity.
  
  
  OBJECTIVE
  To (1) evaluate previously described steps/day cut-points in a sample of White and South Asian British primary school children and (2) use ROC analysis to generate alternative, ethnic specific, steps/day cut-offs for children.
  
  
  METHODS
  Height, body mass and pedometer determined physical activity were assessed in 763 British children (357 boys and 406 girls) from White (n = 593) and South Asian (n = 170) ethnic groups, aged 8-11 years.
  
  
  RESULTS
  The Vincent and Pangrazi cut-points significantly predicted BMI in white (p = 0.006, Adjusted R(2 )= 0.08) and South Asian children (p = 0.039, Adjusted R(2 )= 0.078). The Tudor-Locke et al. cut-points significantly predicted BMI in White children (p = 0.0001, Adjusted R(2 )= 0.079) but not South Asian children (p < 0.05). ROC analysis indicated significant alternative cut-points in White and South Asian boys and girls (all p = 0.04 or better, Adjusted R(2 )= 0.091 for White and 0.09 for South Asian children). Subsequent cut-points associated with healthy weight, when translated to steps/day were 13,625 for White boys, 13,135 for White girls, 10,897 for South Asian boys and 10,161 for South Asian girls.
  
  
  CONCLUSIONS
  Previously published steps/day cut-points for healthy weight may not account for known ethnic variation in physical activity between White and South Asian children in the UK. Alternative, ethnic-specific, cut-points may be better placed to distinguish British children based on pedometer-determined physical activity.
authors: Sport and Exercise Applied Research Group, Faculty of Health and Life Sciences, Coventry University , Coventry , UK.
authors: Michael J
authors: MJ
authors: Duncan
authors: Emma L J
authors: EL
authors: Eyre
authors: Elizabeth
authors: E
authors: Bryant
authors: Samantha L
authors: SL
authors: Birch
mesh_terms: D056044:Actigraphy / Q000379:methods*; D044466:Asian People / Q000706:statistics & numerical data*; D001459:Bangladesh / Q000208:ethnology; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D004739:England; D005260:Female; D006801:Humans; D007194:India / Q000208:ethnology; D008297:Male; D009043:Motor Activity; D010154:Pakistan / Q000208:ethnology; D012372:ROC Curve; D044465:White People / Q000706:statistics & numerical data*
keywords: Ambulatory physical activity; ethnicity; obesity; overweight