title: Methods of Measurement in epidemiology: sedentary Behaviour.
abstract: BACKGROUND
  Research examining sedentary behaviour as a potentially independent risk factor for chronic disease morbidity and mortality has expanded rapidly in recent years.
  
  
  METHODS
  We present a narrative overview of the sedentary behaviour measurement literature. Subjective and objective methods of measuring sedentary behaviour suitable for use in population-based research with children and adults are examined. The validity and reliability of each method is considered, gaps in the literature specific to each method identified and potential future directions discussed.
  
  
  RESULTS
  To date, subjective approaches to sedentary behaviour measurement, e.g. questionnaires, have focused predominantly on TV viewing or other screen-based behaviours. Typically, such measures demonstrate moderate reliability but slight to moderate validity. Accelerometry is increasingly being used for sedentary behaviour assessments; this approach overcomes some of the limitations of subjective methods, but detection of specific postures and postural changes by this method is somewhat limited. Instruments developed specifically for the assessment of body posture have demonstrated good reliability and validity in the limited research conducted to date. Miniaturization of monitoring devices, interoperability between measurement and communication technologies and advanced analytical approaches are potential avenues for future developments in this field.
  
  
  CONCLUSIONS
  High-quality measurement is essential in all elements of sedentary behaviour epidemiology, from determining associations with health outcomes to the development and evaluation of behaviour change interventions. Sedentary behaviour measurement remains relatively under-developed, although new instruments, both objective and subjective, show considerable promise and warrant further testing.
authors.affiliation: British Heart Foundation National Centre for Physical Activity and Health, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK. aa595@medschl.cam.ac.uk
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Atkin
authors.forename: Trish
authors.initials: T
authors.lastname: Gorely
authors.forename: Stacy A
authors.initials: SA
authors.lastname: Clemes
authors.forename: Thomas
authors.initials: T
authors.lastname: Yates
authors.forename: Charlotte
authors.initials: C
authors.lastname: Edwardson
authors.forename: Soren
authors.initials: S
authors.lastname: Brage
authors.forename: Jo
authors.initials: J
authors.lastname: Salmon
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Marshall
authors.forename: Stuart J H
authors.initials: SJ
authors.lastname: Biddle
mesh_terms: D061725:Accelerometry; D003625:Data Collection; D004812:Epidemiologic Methods; D015438:Health Behavior; D006801:Humans; D011187:Posture; D015203:Reproducibility of Results; D012107:Research Design; D057185:Sedentary Behavior; D057566:Self Report