Cross-validation of pedometer-determined cut-points for healthy weight in British children from White and South Asian backgrounds

Ann Hum Biol. 2014 Sep-Oct;41(5):389-94. doi: 10.3109/03014460.2014.881919. Epub 2014 Feb 6.

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 and procedures: 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.

Keywords: Ambulatory physical activity; ethnicity; obesity; overweight.

Publication types

  • Validation Study

MeSH terms

  • Actigraphy / methods*
  • Asian People / statistics & numerical data*
  • Bangladesh / ethnology
  • Body Mass Index
  • Body Weight*
  • Child
  • England
  • Female
  • Humans
  • India / ethnology
  • Male
  • Motor Activity*
  • Pakistan / ethnology
  • ROC Curve
  • White People / statistics & numerical data*