title: Agreement between self-reported and measured height, weight and body mass index in old age--a longitudinal study with 20 years of follow-up.
abstract: BACKGROUND
  self-reported body mass index (BMI) based on self-reported height and weight is a widely used measure of adiposity in epidemiological research. Knowledge about the accuracy of these measures in late life is scarce.
  
  
  OBJECTIVE
  the study aimed to evaluate the accuracy and changes in accuracy of self-reported height, weight and BMI calculated from self-reported height and weight in late life.
  
  
  METHODS
  a longitudinal population-based study with five times of follow-up was conducted.
  
  
  METHODS
  seven hundred seventy-four community-living men and women, aged 40-88 at baseline (mean age 63.9), included in The Swedish Adoption/Twin Study of Aging.
  
  
  METHODS
  participants self-reported their height and weight in a questionnaire, and height and weight were measured by experienced research nurses at an in-person testing five times during a 20-year period. BMI was calculated as weight (kilogramme)/height (metre)(2).
  
  
  RESULTS
  latent growth curve modelling showed an increase in the mean difference between self-reported and measured values over time for height (0.038 cm/year) and BMI (0.016 kg/m(2)/year), but not for weight.
  
  
  CONCLUSIONS
  there is a very small increase in the mean difference between self-reported and measured BMI with ageing, which probably would not affect the results when self-reported BMI is used as a continuous variable in longitudinal studies.
authors.affiliation: Institute of Gerontology, Jönköping University, Sweden. anna.dahl@hhj.hj.se <anna.dahl@hhj.hj.se>
authors.forename: Anna K
authors.initials: AK
authors.lastname: Dahl
authors.forename: Linda B
authors.initials: LB
authors.lastname: Hassing
authors.forename: Eleonor I
authors.initials: EI
authors.lastname: Fransson
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Pedersen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000706:statistics & numerical data*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012649:Self Concept; D011795:Surveys and Questionnaires
references.citation: BMC Public Health. 2001;1:11
references.pmid: 11716792
references.citation: J Public Health Med. 1998 Jun;20(2):206-10
references.pmid: 9675741
references.citation: Am J Epidemiol. 1999 Nov 1;150(9):969-77
references.pmid: 10547143
references.citation: J Gerontol A Biol Sci Med Sci. 1997 Mar;52(2):M117-25
references.pmid: 9060980
references.citation: Int J Epidemiol. 1997 Aug;26(4):860-6
references.pmid: 9279620
references.citation: J Intern Med. 2002 Sep;252(3):184-205
references.pmid: 12270000
references.citation: Swiss Med Wkly. 2008 Apr 5;138(13-14):204-10
references.pmid: 18389393
references.citation: Am J Clin Nutr. 1990 Dec;52(6):1125-33
references.pmid: 2239790
references.citation: Age Ageing. 2002 May;31(3):169-74
references.pmid: 12006304
references.citation: Int J Epidemiol. 2000 Jun;29(3):456-64
references.pmid: 10869317
references.citation: Dev Psychol. 2002 Jan;38(1):115-42
references.pmid: 11806695
references.citation: J Gerontol A Biol Sci Med Sci. 2010 Jan;65(1):57-62
references.pmid: 19349594
references.citation: Eur J Clin Nutr. 1999 Dec;53(12):905-14
references.pmid: 10602346
references.citation: J Am Diet Assoc. 2001 Jan;101(1):28-34; quiz 35-6
references.pmid: 11209581
references.citation: Int J Obes Relat Metab Disord. 1993 Nov;17(11):663-7
references.pmid: 8281225
references.citation: J Nutr Health Aging. 2008 Feb;12(2):108-15
references.pmid: 18264637
references.citation: Int J Epidemiol. 2004 Dec;33(6):1398-9
references.pmid: 15358740
references.citation: J Nutr Health Aging. 2000;4(4):223-8
references.pmid: 11115805