Assessment of the Construct Validity of the EQ-5D in Patients with Acute Cough/Lower Respiratory Tract Infections

Although EQ-5D has been used in the context of acute cough/lower respiratory tract infections (acute cough/LRTI), it has not been formally validated in this disease area. The primary aim of this study is to assess the construct validity of EQ-5D as a measure for economic evaluation in the context of acute cough/lower respiratory tract infections. Data were collected alongside an observational study of the management of patients with acute cough/LRTI in thirteen European countries. However, the analysis was limited to 349 patients from the UK. Hypotheses were specified a priori and tested in order to establish the construct validity of EQ-5D. Statistical methods used to test the a priori hypotheses included Wilcoxon signed rank sum test, Kruskal-Wallis test, Chi-square test and regression analysis. Most of the relationships that were tested were in line with the a priori hypotheses. The main results indicate that there was a negative relationship between symptom severity scores and EQ-5D, smoking was associated with worse EQ-5D scores and EQ-5D was able to discriminate between patients with headache, interference with normal activities and disturbed sleep. This study also showed that the EQ-5D is moderately responsive in patients with acute cough/LRTI, and is a suitable measure for use in economic evaluation studies of acute cough/LRTI.