title: Do chronic disease patients value generic health states differently from individuals with no chronic disease? A case of a multicultural Asian population.
abstract: BACKGROUND
  There is conflicting evidence as to whether patients with chronic disease value hypothetical health states differently from individuals who have not experienced any long-lasting diseases. Furthermore, most studies regarding this issue have been conducted in western countries, with only one conducted in Asia. We aimed to evaluate possible systematic differences in the valuation of EuroQol Group five dimensions 3-level (EQ-5D-3L) health states by chronic disease patients and a population with no chronic disease in Singapore.
  
  
  METHODS
  A face-to-face survey for the valuation of the 42 health states of the EQ-5D-3L using the visual analogue scale (VAS) method was conducted in Singapore. The survey also asked participants to report any chronic diseases they had. Ordinary least-square regression models were employed to assess possible differences in the valuation scores of all health states, severe health states and non-severe health states by individual chronic disease patient groups (diabetes, rheumatism, hypertension, heart diseases and lung diseases) and by a group of participants with no chronic disease. A difference of 4 to 8 points on the 100-point VAS was considered to be of practical significance.
  
  
  RESULTS
  The analysis included 332 participants with at least one chronic disease and 651 participants with no chronic disease. After taking health state descriptors and covariates into account, mean valuation scores of the 42 health states by the heart disease group were higher by 4.6 points (p-value = 0.032) compared to the no chronic disease group. Specifically, the heart disease group valued severe health states 5.4 points higher (p-value = 0.025) than the no chronic disease group. There was no practically significant difference in the mean valuation score of non-severe health states between the heart disease group and the no chronic disease group. No practically significant differences were found in the mean valuation score of all health states, severe health states and non-severe health states between any other chronic disease group and the no chronic disease group.
  
  
  CONCLUSIONS
  In Singapore, heart disease patients valued EQ-5D-3L severe health states differently from individuals with no chronic disease. Other chronic disease groups did not value EQ-5D-3L health states differently from the no chronic disease group.
authors.affiliation: Biostatistics, Singapore Clinical Research Institute, Singapore, Singapore. mihir.gandhi@scri.edu.sg.|Centre for Quantitative Medicine, Duke-NUS Graduate Medical School, Singapore, Singapore. mihir.gandhi@scri.edu.sg.|Department of International Health, School of Medicine, University of Tampere, Tampere, Finland. mihir.gandhi@scri.edu.sg.
authors.forename: Mihir
authors.initials: M
authors.lastname: Gandhi
authors.affiliation: Department of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore. julian.thumboo@sgh.com.sg.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. julian.thumboo@sgh.com.sg.
authors.forename: Julian
authors.initials: J
authors.lastname: Thumboo
authors.affiliation: School of Public Health, National University of Singapore, Singapore, Singapore. ephln@nus.edu.sg.
authors.forename: Nan
authors.initials: N
authors.lastname: Luo
authors.affiliation: Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore. phawhl@nus.edu.sg.
authors.forename: Hwee-Lin
authors.initials: HL
authors.lastname: Wee
authors.affiliation: Centre for Quantitative Medicine, Duke-NUS Graduate Medical School, Singapore, Singapore. yinbun.cheung@duke-nus.edu.sg.|Department of International Health, School of Medicine, University of Tampere, Tampere, Finland. yinbun.cheung@duke-nus.edu.sg.
authors.forename: Yin-Bun
authors.initials: YB
authors.lastname: Cheung
mesh_terms: D000328:Adult; D002908:Chronic Disease / Q000453:epidemiology* / Q000523:psychology*; D003430:Cross-Sectional Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011788:Quality of Life / Q000523:psychology*; D012846:Singapore / Q000453:epidemiology; D011795:Surveys and Questionnaires / Q000592:standards*; D064232:Visual Analog Scale