title: The influence of ethnicity on health-related quality of life in diabetes mellitus: a population-based, multiethnic study.
abstract: OBJECTIVE
  The aims of this study were to evaluate the influence of ethnicity on health-related quality of life (HRQoL) in diabetic participants using both profile [the Short-Form 36 (SF-36)] and single-index (the SF-6D) instruments and to evaluate the usefulness of the SF-6D as a summary measure for the SF-36.
  
  
  METHODS
  Using data from a cross-sectional, population-based survey of Chinese, Malay, and Indians in Singapore, we analyzed the influence of ethnicity and other variables on each SF-36 scale and SF-6D scores using linear regression models to adjust for the influence of known determinants of HRQoL.
  
  
  RESULTS
  Data from 309 diabetic respondents were analyzed. Compared with other ethnicities, Indians were most likely to report impaired HRQoL. The unadjusted influence of ethnicity on HRQoL exceeded the minimum clinically important difference (MCID) for all SF-36 scales (MCID: 5 points) and the SF-6D (MCID: 0.033 points). After adjusting for gender, age, and education, the influence of Chinese ethnicity exceeded the MCID for all SF-36 scales, except vitality (VT) and mental health (MH), as well as for the SF-6D. The influence of Malay ethnicity exceeded the MCID only for the SF-36 MH scale and the SF-6D. The influence of ethnicity on HRQoL persisted after adjusting further for other determinants of HRQoL. The SF-6D reflected the ethnic trends for some but not all SF-36 scales.
  
  
  CONCLUSIONS
  After adjusting for demographic, socioeconomic, and other factors known to influence HRQoL, ethnicity remained an important factor influencing HRQoL in this population-based multiethnic sample of diabetic Asians. Further studies to identify modifiable factors explaining the ethnic disparities in HRQoL among diabetic participants are needed. The SF-6D may be a useful summary measure for the SF-36.
authors.affiliation: Department of Pharmacy, National University of Singapore, and Department of Rheumatology and Immunology, Singapore General Hospital, Singapore, Republic of Singapore.
authors.forename: Hwee-Lin
authors.initials: HL
authors.lastname: Wee
authors.forename: Shu-Chuen
authors.initials: SC
authors.lastname: Li
authors.forename: Yin-Bun
authors.initials: YB
authors.lastname: Cheung
authors.forename: Kok-Yong
authors.initials: KY
authors.lastname: Fong
authors.forename: Julian
authors.initials: J
authors.lastname: Thumboo
mesh_terms: D000328:Adult; D000368:Aged; D002681:China / Q000208:ethnology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000208:ethnology* / Q000523:psychology; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007194:India / Q000208:ethnology; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D044382:Population Groups / Q000208:ethnology / Q000706:statistics & numerical data; D011788:Quality of Life; D012846:Singapore; D012923:Social Class