title: The Impact of Diabetes-Related Complications on Preference-Based Measures of Health-Related Quality of Life in Adults with Type I Diabetes.
abstract: This study estimates health-related quality of life (HRQoL) or utility decrements associated with type 1 diabetes mellitus (T1DM) using data from a UK research program on the Dose Adjustment For Normal Eating (DAFNE) education program.
  
  
  
  A wide range of data was collected from 2341 individuals who undertook a DAFNE course in 2009-2012, at baseline and for 2 subsequent years. We use fixed- and random-effects linear models to generate utility estimates for T1DM using different instruments: EQ-5D, SF-6D, and EQ-VAS. We show models with and without controls for HbA1c and depression, which may be endogenous (if, for example, there is reverse causality in operation).
  
  
  
  We find strong evidence of an unobserved individual effect, suggesting the superiority of the fixed-effects model. Depression shows the greatest decrement across all the models in the preferred fixed-effects model. The fixed-effects EQ-5D model also finds a significant decrement from retinopathy, body mass index, and HbA1c (%). Estimating a decrement using the fixed-effects model is not possible for some conditions where there are few new cases. In the random-effects model, diabetic foot disease shows substantial utility decrements, yet these are not significant in the fixed-effects models.
  
  
  
  Utility decrements have been calculated for a wide variety of health states in T1DM that can be used in economic analyses. However, despite the large data set, the low incidence of several complications leads to uncertainty in calculating the utility weights. Depression and diabetic foot disease result in a substantial loss in HRQoL for patients with T1DM. HbA1c (%) appears to have an independent negative impact on HRQoL, although concerns remain regarding the potential endogeneity of this variable.
authors.affiliation: School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom (TP, AB, HB, JK)
authors.forename: Tessa
authors.initials: T
authors.lastname: Peasgood
authors.affiliation: School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom (TP, AB, HB, JK)
authors.forename: Alan
authors.initials: A
authors.lastname: Brennan
authors.affiliation: Department of Diabetes and Endocrinology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom (PM)
authors.forename: Peter
authors.initials: P
authors.lastname: Mansell
authors.affiliation: Academic Unit of Diabetes, Endocrinology and Metabolism, Department of Human Metabolism, School of Medicine and Biomedical Sciences, Sheffield, United Kingdom (JE)
authors.forename: Jackie
authors.initials: J
authors.lastname: Elliott
authors.affiliation: School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom (TP, AB, HB, JK)
authors.forename: Hasan
authors.initials: H
authors.lastname: Basarir
authors.affiliation: School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom (TP, AB, HB, JK)
authors.forename: Jen
authors.initials: J
authors.lastname: Kruger
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003863:Depression / Q000453:epidemiology; D048909:Diabetes Complications / Q000453:epidemiology / Q000523:psychology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D006442:Glycated Hemoglobin; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires / Q000592:standards*; D006113:United Kingdom
chemical_list: D006442:Glycated Hemoglobin
keywords: EQ-5D; EQ-VAS; HbA1c; SF-6D; T1DM; depression; health-related quality of life; type 1 diabetes; utility