title: Video instructions improve accuracy of self-measures of waist circumference compared with written instructions.
abstract: OBJECTIVE
  To determine whether video-based instructions improve the accuracy of self-measures of waist and hip circumference compared with written instructions.
  
  
  METHODS
  Population-based, cross-sectional study. Self-measurements of waist circumference (WC) and hip circumference (HC) of fifty-seven participants randomly allocated to receive either written instruction or video instruction were compared with those of a trained technician.
  
  
  METHODS
  Aberdeen, Scotland, and Brussels, Belgium, between February and April 2010.
  
  
  METHODS
  Adults aged 18-62 years with a high level of English language and no prior training in anthropometry.
  
  
  RESULTS
  WC was significantly overestimated by the written method (1·75 cm bias; P = 0·007) but not the video method (0·95 cm bias; P = 0·239). HC was significantly underestimated in both written (-0·35 cm bias; P = 0·009) and video methods (-0·75 cm bias; P = 0·046). Reliability was not significantly affected by age, sex, BMI or WC. Bland-Altman plots demonstrated wide limits of agreement for WC (-6·83, 6·08 cm for written method; -10·14, 6·72 cm for video method) and HC (-12·85, 1·60 cm for written method; -10·82, 2·50 cm for video method).
  
  
  CONCLUSIONS
  Video technology can support more accurate self-measurements of anthropometric data in epidemiological studies. Further research is warranted using larger and more heterogeneous samples in order that results can be generalised.
authors: Community Dietetic Department, NHS Grampian, Westholme, Woodend Hospital Site, Queens Road, Aberdeen AB15 6LS, UK.
authors: Dara F
authors: DF
authors: McEneaney
authors: Susan C
authors: SC
authors: Lennie
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000886:Anthropometry / Q000295:instrumentation* / Q000379:methods*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D017678:Sex Distribution; D014741:Video Recording; D055105:Waist Circumference; D049629:Waist-Hip Ratio; D055815:Young Adult