title: Assessing the impact of visual acuity on quality of life in individuals with type 2 diabetes using the short form-36.
abstract: OBJECTIVE
  We sought to ascertain quality-of-life measures and utility values associated with visual acuity in type 2 diabetes.
  
  
  METHODS
  The Medical Outcome Study Short Form with 36 items (SF-36) was administered to 4,051 individuals with type 2 diabetes who were enrolled in the Lipids in Diabetes Study, and their best attainable vision was determined using an Early Treatment of Diabetic Retinopathy Study chart, expressed as a LogMAR score. Eight domain scores and a utility value representing an overall quality-of-life score were calculated using predefined algorithms. The associations between quality of life measured and best-eye visual acuity were assessed graphically and by regression analysis.
  
  
  RESULTS
  All eight SF-36 domain scores were negatively associated with reduced visual acuity. The impact of lower levels of visual acuity ranged from a decline of 1.3 units for a 0.1-LogMAR increase for physical functioning and 0.6 units in mental health. Regression analysis indicated a negative association (P < 0.001) between utility and reduced visual acuity after controlling for sex, BMI, smoking status, and history of diabetes complications. Patients whose LogMAR scores equated to legally blind had, on average, 0.054 (95% CI 0.034-0.074) lower utility compared with patients with normal visual acuity.
  
  
  CONCLUSIONS
  Reduced visual acuity is negatively associated with quality of life. The utility scores estimated here should inform studies quantifying the burden of diabetes and those evaluating potential therapies for treating or preventing diabetic eye diseases.
authors.affiliation: Diabetes Trials Unit, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK. philip.clarke@dphpc.ox.ac.uk
authors.forename: Philip M
authors.initials: PM
authors.lastname: Clarke
authors.forename: Judit
authors.initials: J
authors.lastname: Simon
authors.forename: Carole A
authors.initials: CA
authors.lastname: Cull
authors.forename: Rury R
authors.initials: RR
authors.lastname: Holman
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000523:psychology*; D003930:Diabetic Retinopathy / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D014792:Visual Acuity / Q000502:physiology*