Psychometric properties of the EQ-5D-5L in Thai patients with chronic diseases.

Abstract

Due to the problem of high ceiling effects of the EQ-5D-3L, the EQ-5D-5L was developed. However, little was known about the full psychometric properties of the EQ-5D-5L. Thus, this study aimed to evaluate its practicality, reliability, validity, and responsiveness in Thai patients with chronic diseases. One thousand one hundred and fifty-six adults taking a medicine at least 3months were identified from three university hospitals in Bangkok, Thailand, between July 2014 and March 2015. Practicality was evaluated by administration times and ceiling effects. Test-retest reliability was assessed using weighted kappa and intraclass correlation coefficients (ICCs). Validity was tested with correlations between the EQ-5D-5L and WHOQoL-BREF and SF-12v2, and known-groups validity. Responsiveness was measured with standardized effect sizes (SES). The mean administration time was approximately 2min, and the ceiling effect of the EQ-5D-5L index was 13.6%. The weighted kappa values and ICC of the EQ-5D-5L were 0.48-0.61 and 0.82, respectively. Similar dimensions of the EQ-5D-5L had higher correlations with those of WHOQoL-BREF and SF-12v2. As expected, elderly, female, low-educated, unemployed, higher number of comorbidities and medicines, patients' perception of poor disease control, and having an adverse drug reaction tended to have poorer EQ-5D-5L scores. The SES of EQ-5D-5L index and EQ-VAS were considered small (0.33-0.42) for the improved group. For the worsened group, the SES of the EQ-5D-5L index were considered small (-0.29) but that of the EQ-VAS considered large (-0.82). The EQ-5D-5L was practical, reliable, valid, and responsive in Thai patients with chronic diseases.