The use of the EQ-5D preference-based health status measure in adults with Type 2 diabetes mellitus

BACKGROUND: The EQ-5D is a generic preference-based health status measure that has been widely applied to measure the impact of Type 2 diabetes mellitus. This review summarizes evidence on the validity, reliability and responsiveness of the EQ-5D in studies of Type 2 diabetes and provides a catalogue of EQ-5D index scores for Type 2 diabetes and various complications and subgroups. METHODS: A structured search was conducted (1987-2009) using keywords relevant to Type 2 diabetes and the EQ-5D. Original research studies in Type 2 diabetes that reported EQ-5D results and/or measurement properties were included. RESULTS: Of the 59 included articles, 54 publications reported EQ-5D responses and 39 papers presented evidence on the measurement properties of the EQ-5D. Studies that reported measurement properties supported construct, convergent and discriminant validity, test-retest reliability and responsiveness of the EQ-5D in Type 2 diabetes. Several studies reported a ceiling effect for the EQ-5D and an inability to capture multiple complications was observed. EQ-5D index scores ranged from 0.20 (severe diabetic peripheral neuropathic pain) to 0.88 (general population: good HbA(1c) level). For six subgroups, sufficient studies were available to calculate pooled mean index scores (95% CI): general population 0.67 (0.59-0.75), no complications 0.76 (0.68-0.83), microvascular complications 0.73 (0.57-0.89), macrovascular complications 0.73 (0.57-0.88), diabetic peripheral neuropathic pain 0.45 (0.39-0.51) and retinopathy 0.57 (0.46-0.69). CONCLUSIONS: Evidence supported validity, reliability and responsiveness of the EQ-5D in Type 2 diabetes. EQ-5D index scores associated with Type 2 diabetes and various complications can be useful for modelling health outcomes in economic evaluations of health programmes for Type 2 diabetes.