title: Using Rasch analysis to evaluate the validity of the diabetes-specific version of the Illness Perception Questionnaire--Revised.
abstract: This study used Rasch analysis to examine the psychometric validity of the Illness Perception Questionnaire--Revised to assess beliefs about diabetes in 470 participants with Type 2 diabetes and 71 participants with Type 1 diabetes. All Illness Perception Questionnaire--Revised scales had psychometric issues, which included poorly utilised response categories, poor scale precision and multidimensionality. Following re-engineering, only four of the eight scales (Consequences, Illness coherence, Timeline cyclical and Emotional representations) were psychometrically adequate according to the Rasch model. The diabetes-specific version of the Illness Perception Questionnaire--Revised provides suboptimal assessment of beliefs held by patients with diabetes.
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Australia grees@unimelb.edu.au.
authors.forename: Gwyneth
authors.initials: G
authors.lastname: Rees
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Australia Singapore Eye Research Institute, National University of Singapore, Singapore Duke-National University of Singapore Graduate Medical School, Singapore.
authors.forename: Ecosse L
authors.initials: EL
authors.lastname: Lamoureux
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Australia.
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Australia.
authors.forename: Bonnie A
authors.initials: BA
authors.lastname: Sturrock
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Australia.
authors.forename: Eva K
authors.initials: EK
authors.lastname: Fenwick
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011594:Psychometrics; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: Rasch analysis; diabetes; illness perception; psychometric evaluation; quantitative methods