title: Assessing levels of agreement between two commonly used oral health-related quality of life measures.
abstract: OBJECTIVE
  This study aimed to assess the level of agreement between two commonly used oral health-related quality of life (OHRQoL) measures, the short form of the Oral Health Impact Profile (OHIP14) and the Oral Impacts on Daily Performances (OIDP).
  
  
  METHODS
  A sample of 1,675 15- to 16-year-old students attending all schools in Bauru (Sao Paulo, Brazil) was selected. The impact of oral conditions on quality of life in the last 6 months was reported using both OHIP14 and OIDP. To allow for comparison with the 100 percent OIDP score, OHIP14 scores were converted to percentages. Then, agreement between the two OHRQoL measures was analyzed using the Bland and Altman method.
  
  
  RESULTS
  The mean difference between OHIP14 and OIDP was 6.48 percent [confidence interval 95% (6.08; 6.89)], with higher scores reported for OHIP14 than for OIDP. Besides, 95 percent of the differences between the two OHRQoL measures were between -10.59 and 23.56 percent. Finally, differences between OHIP14 and OIDP increased significantly as the magnitude of their average increased (P < 0.001).
  
  
  CONCLUSIONS
  There was a moderate level of agreement between OHIP14 and OIDP, which may be partly due to the fact that both OHRQoL measures assess different levels of oral impacts on quality of life in addition to having different scoring systems.
authors.affiliation: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London WC1E 6BT, UK. e.bernabe@ucl.ac.uk
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bernabé
authors.forename: Cesar M
authors.initials: CM
authors.lastname: de Oliveira
authors.forename: Aubrey
authors.initials: A
authors.lastname: Sheiham
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsakos
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D001938:Brazil; D005260:Female; D006801:Humans; D008297:Male; D009909:Oral Health; D011594:Psychometrics; D011788:Quality of Life; D012044:Regression Analysis; D018434:Sickness Impact Profile