Reliability and validity of Chinese version of a tool to assess the quality of life in idiopathic pulmonary fibrosis in patients with interstitial lung disease

Abstract

ObjectiveThis paper aims to determine the reliability and validity of the Chinese version of a tool that assesses the quality of life in idiopathic pulmonary fibrosis (cATAQ-IPF) in patients with interstitial lung disease (ILD). MethodsWe used the process of scale introduction to establish cATAQ-IPF. The content validity of the scale was evaluated by six experts. A total of 92 patients with ILD completed the cATAQ-IPF, St. George's respiratory questionnaire (SGRQ), and The Medical Research Council dyspnoea scale at the baseline, and 15 patients completed cATAQ-IPF at the follow-up period 2 weeks later. Thus, yielding data were used to assess various psychometric properties of cATAQ-IPF. Intraclass correlation coefficient (ICC), Cronbach's α coefficient, content validity index (CVI), item-level CVI (I-CVI), Pearson's coefficients, criterion-relation validity, and known-group validity were used for data analysis. ResultsThe cATAQ-IPF showed excellent test–retest reliability (ICC = 0.95), except for the therapy domain (Cronbach's α = 0.60) and acceptable internal consistency (Cronbach's α = 0.96 for the total). The scale-level CVI was 0.80, and the I-CVI was in the range of 0.78–1.00. The total cATAQ-IPF score was strongly correlated with the SGRQ total score (r = 0.71, P < 0.01). The cATAQ-IPF score of patients with ILD was 250.74 ± 47.39, and that of patients with IPF was 287.90 ± 22.56. Patients with IPF possessed considerable impairments in health-related quality of life according to the cATAQ-IPF score (t = 4.94, P < 0.01). ConclusionsThe cATAQ-IPF is a reliable and valid instrument for the evaluation of quality of life of Chinese patients with various forms of ILD.