title: Inaccuracy in self-report of fractures may underestimate association with health outcomes when compared with medical record based fracture registry.
abstract: OBJECTIVE
  Misreporting fractures in questionnaires is known. However, the effect of misreporting on the association of fractures with subsequent health outcomes has not been examined.
  
  
  METHODS
  Data from a fracture registry (FR) developed from an extensive review of radiographic and medical records were related to self-report of fracture for 2,255 participants from the AGES Reykjavik Study. This data was used to determine false negative and false positive rates of self-reported fractures, correlates of misreporting, and the potential effect of the misreporting on estimates of health outcomes following fractures.
  
  
  RESULTS
  In women, the false positive rate decreased with age as the false negative rate increased with no clear trend with age in men. Kappa values for agreement between FR and self-report were generally higher in women than men with the best agreement for forearm fracture (men 0.64 and women 0.82) and the least for rib (men 0.28 and women 0.25). Impaired cognition was a major factor associated with discordant answers between FR and self-report, OR 1.7 (95% CI: 1.3-2.1) (P < 0.0001). We estimated the effect of misreporting on health after fracture by comparison of the association of the self-report of fracture and fracture from the FR, adjusting for those factors associated with discordance. The weighted attenuation factor measured by mobility and muscle strength was 11% (95% CI: 0-24%) when adjusted for age and sex but reduced to 6% (95% CI: -10-22%) when adjusted for cognitive impairment.
  
  
  CONCLUSIONS
  Studies of hip fractures should include an independent ascertainment of fracture but for other fractures this study supports the use of self-report.
authors.affiliation: Icelandic Heart Association, Holtasmari 1, 201, Kopavogur, Iceland. kristin@hjarta.is
authors.forename: Kristin
authors.initials: K
authors.lastname: Siggeirsdottir
authors.forename: Thor
authors.initials: T
authors.lastname: Aspelund
authors.forename: Gunnar
authors.initials: G
authors.lastname: Sigurdsson
authors.forename: Brynjolfur
authors.initials: B
authors.lastname: Mogensen
authors.forename: Milan
authors.initials: M
authors.lastname: Chang
authors.forename: Birna
authors.initials: B
authors.lastname: Jonsdottir
authors.forename: Gudny
authors.initials: G
authors.lastname: Eiriksdottir
authors.forename: Lenore J
authors.initials: LJ
authors.lastname: Launer
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.forename: Brynjolfur Y
authors.initials: BY
authors.lastname: Jonsson
authors.forename: Vilmundur
authors.initials: V
authors.lastname: Gudnason
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology*; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008485:Medical Audit; D012042:Registries; D015203:Reproducibility of Results; D012650:Self Disclosure; D011795:Surveys and Questionnaires