title: Use of population-referenced total activity counts percentiles to assess and classify physical activity of population groups.
abstract: Population-referenced total activity counts per day (TAC/d) percentiles provide public health practitioners a standardized measure of physical activity (PA) volume obtained from an accelerometer that can be compared across populations. The purpose of this study was to describe the application of TAC/d population-referenced percentiles to characterize the PA levels of population groups relative to US estimates.
  
  
  
  A total of 679 adults participating in the 2011 NYC Physical Activity Transit survey wore an ActiGraph accelerometer on their hip for seven consecutive days. Accelerometer-derived TAC/d was classified into age- and gender-specific quartiles of US population-referenced TAC/d to compare differences in the distributions by borough (N=5).
  
  
  
  Males in Brooklyn, Manhattan, and Staten Island had significantly greater TAC/d than US males. Females in Brooklyn and Queens had significantly greater levels of TAC/d compared to US females. The proportion of males in each population-referenced TAC/d quartile varied significantly by borough (χ(2)(12)=2.63, p=0.002), with disproportionately more men in Manhattan and the Bronx found to be in the highest and lowest US population-referenced TAC/d quartiles, respectively. For females, there was no significant difference in US population-reference TAC/d quartile by borough (χ(2)(12)=1.09, p=0.36).
  
  
  
  These results demonstrate the utility of population-referenced TAC/d percentiles in public health monitoring and surveillance. These findings also provide insights into the PA levels of NYC residents relative to the broader US population, which can be used to guide health promotion efforts.
authors.affiliation: Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, MD, United States. Electronic address: dana.wolff@nih.gov.
authors.forename: Dana L
authors.initials: DL
authors.lastname: Wolff-Hughes
authors.affiliation: Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, MD, United States.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Troiano
authors.affiliation: Department of Kinesiology, Recreation & Sports Studies, The University of Tennessee, Knoxville, TN, United States.
authors.forename: William R
authors.initials: WR
authors.lastname: Boyer
authors.affiliation: Department of Kinesiology, Recreation & Sports Studies, The University of Tennessee, Knoxville, TN, United States.
authors.forename: Eugene C
authors.initials: EC
authors.lastname: Fitzhugh
authors.affiliation: Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, MD, United States.
authors.forename: James J
authors.initials: JJ
authors.lastname: McClain
mesh_terms: D061725:Accelerometry / Q000379:methods; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D009519:New York City; D011795:Surveys and Questionnaires; D014481:United States
keywords: Actigraphy; Epidemiologic measurements; Health promotion; Motor activity; New York City