title: Positive and negative affect and oral health-related quality of life.
abstract: BACKGROUND
  The aims of the study were to assess the impact of both positive (PA) and negative affect (NA) on self-reported oral health-related quality of life and to determine the effect of including affectivity on the relationship between oral health-related quality of life and a set of explanatory variables consisting of oral health status, socio-economic status and dental visiting pattern.
  
  
  METHODS
  A random sample of 45-54 year-olds from metropolitan Adelaide, South Australia was surveyed by mailed self-complete questionnaire during 2004-05 with up to four follow-up mailings of the questionnaire to non-respondents (n = 986 responded, response rate = 44.4%). Oral health-related quality of life was measured using OHIP-14 and affectivity using the Bradburn scale. Using OHIP-14 and subscales as the dependent variables, regression models were constructed first using oral health status, socio-economic characteristics and dental visit pattern and then adding PA and NA as independent variables, with nested models tested for change in R-squared values.
  
  
  RESULTS
  PA and NA exhibited a negative correlation of -0.49 (P < 0.01). NA accounted for a larger percentage of variance in OHIP-14 scores (3.0% to 7.3%) than PA (1.4% to 4.6%). In models that included both PA and NA, PA accounted for 0.2% to 1.1% of variance in OHIP-14 scores compared to 1.8% to 3.9% for NA.
  
  
  CONCLUSIONS
  PA and NA both accounted for additional variance in quality of life scores, but did not substantially diminish the effect of established explanatory variables such as oral health status, socio-economic status and dental visit patterns.
authors.affiliation: Australian Research Centre for Population Oral Health, School of Dentistry, The University of Adelaide, South Australia 5005 Australia. david.brennan@adelaide.edu.au
authors.forename: David S
authors.initials: DS
authors.lastname: Brennan
authors.forename: Kiran A
authors.initials: KA
authors.lastname: Singh
authors.forename: A John
authors.initials: AJ
authors.lastname: Spencer
authors.forename: Kaye F
authors.initials: KF
authors.lastname: Roberts-Thomson
mesh_terms: D000339:Affect; D000704:Analysis of Variance; D003752:Dental Health Services / Q000706:statistics & numerical data*; D003778:Dentures / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009909:Oral Health; D010551:Personality; D011594:Psychometrics / Q000295:instrumentation; D011788:Quality of Life / Q000523:psychology*; D012649:Self Concept; D018434:Sickness Impact Profile; D012923:Social Class; D013021:South Australia; D011795:Surveys and Questionnaires; D014076:Tooth Diseases / Q000523:psychology* / Q000628:therapy; D014505:Urban Population