Content validation of two SF-36 subscales for use in type 2 diabetes and non-dialysis chronic kidney disease-related anemia
Department of Quantitative Health Sciences
Medical Subject Headings
Health Surveys; Health Status; Questionnaires; Activities of Daily Living; Quality of Life; Sickness Impact Profile; Diabetes Mellitus, Type 2
Biostatistics | Epidemiology | Health Services Research
PURPOSE: This study aimed to evaluate the relevance and importance of two SF-36 subscales, Vitality (VT) and Physical Function (PF), to assess concepts of energy and physical function in patients with type 2 diabetes mellitus (DM) and non-dialysis CKD-related anemia.
METHODS: Patients with clinical history of DM and non-dialysis CKD-related anemia (n = 68) were identified as follows: 40 participated in concept elicitation (CE) interviews; 20 in cognitive interviews (CI), and 8 in pilot interviews. Relevance and importance ratings for SF-36 VT and PF items were obtained. Interviews were recorded, transcribed, and patient expressions of concepts coded. Inter-rater agreement was used to evaluate coding consistency. Concepts elicited were mapped to SF-36 VT and PF items.
RESULTS: Patients (n = 64) were 65.6% women, 42.2% Caucasian, with mean age of 66.1 +/- 11.6 years. Of 830 coded concepts, 388 (47%) were "Energy" expressions and 287 (35%) were "PF limitations" expressions. Low energy was reported by 85% patients and rated as an important limitation by 88%. Limitations in PF were reported by 56-82% patients and rated important by 44-96%. CE and CI quotes correspond well to SF-36 VT and PF items.
CONCLUSION: SF-36 VT and PF contents were suitable for assessing energy and physical function limitations, respectively, in this patient population.
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Citation: Qual Life Res. 2010 Dec 16. Link to article on publisher's site