title: Health-related quality of life measured using the EQ-5D-5L: South Australian population norms.
abstract: BACKGROUND
  Although a five level version of the widely-used EuroQol 5 dimensions (EQ-5D) instrument has been developed, population norms are not yet available for Australia to inform the future valuation of health in economic evaluations. The aim of this study was to estimate HrQOL normative values for the EQ-5D-5L preference-based measure in a large, randomly selected, community sample in South Australia.
  
  
  METHODS
  The EQ-5D-5L instrument was included in the 2013 South Australian Health Omnibus Survey, an interviewer-administered, face-to-face, cross-sectional survey. Respondents rated their level of impairment across dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) and global health rating on a visual analogue scale (EQ-VAS). Utility scores were derived using the newly-developed UK general population-based algorithm and relationships between utility and EQ-VAS scores and socio-demographic factors were also explored using multivariate regression analyses.
  
  
  RESULTS
  Ultimately, 2,908 adults participated in the survey (63.4 % participation rate). The mean utility and EQ-VAS scores were 0.91 (95 CI 0.90, 0.91) and 78.55 (95 % CI 77.95, 79.15), respectively. Almost half of respondents reported no problems across all dimensions (42.8 %), whereas only 7.2 % rated their health >90 on the EQ-VAS (100 = the best health you can imagine). Younger age, male gender, longer duration of education, higher annual household income, employment and marriage/de facto relationships were all independent, statistically significant predictors of better health status (p < 0.01) measured with the EQ-VAS. Only age and employment status were associated with higher utility scores, indicating fundamental differences between these measures of health status.
  
  
  CONCLUSIONS
  This is the first Australian study to apply the EQ-5D-5L in a large, community sample. Overall, findings are consistent with EQ-5D-5L utility and VAS scores reported for other countries and indicate that the majority of South Australian adults report themselves in full health. When valuing health in Australian economic evaluations, the utility population norms can be used to estimate HrQOL. More generally, the EQ-VAS score may be a better measure of population health given the smaller ceiling effect and broader coverage of HrQOL dimensions. Further research is recommended to update EQ-5D-5L population norms using the Australian general population specific scoring algorithm once this becomes publically available.
authors.affiliation: Flinders Health Economics Group, Flinders University, Repatriation General Hospital, Rm 55, Level 1, Block A, Repatriation General Hospital, Daws Road, Daw Park, SA, 5041, Australia. nicola.mccaffrey@flinders.edu.au.|Palliative and Supportive Care, Bedford Park, Flinders University, Bedford Park, SA, 5042, Australia. nicola.mccaffrey@flinders.edu.au.
authors.forename: Nikki
authors.identifier: http://orcid.org/0000-0003-3684-3723
authors.initials: N
authors.lastname: McCaffrey
authors.affiliation: Flinders Health Economics Group, Flinders University, Repatriation General Hospital, Rm 55, Level 1, Block A, Repatriation General Hospital, Daws Road, Daw Park, SA, 5041, Australia.
authors.forename: Billingsley
authors.initials: B
authors.lastname: Kaambwa
authors.affiliation: Palliative and Supportive Care, Bedford Park, Flinders University, Bedford Park, SA, 5042, Australia.
authors.forename: David C
authors.initials: DC
authors.lastname: Currow
authors.affiliation: Flinders Health Economics Group, Flinders University, Repatriation General Hospital, Rm 55, Level 1, Block A, Repatriation General Hospital, Daws Road, Daw Park, SA, 5041, Australia.
authors.forename: Julie
authors.initials: J
authors.lastname: Ratcliffe
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006306:Health Surveys / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D012737:Sex Factors; D012959:Socioeconomic Factors; D013021:South Australia
keywords: EQ-5D; Population norms; Quality of life; Utility