Cultural adaptation and psychometric properties of the Chinese Burden of Treatment Questionnaire (C-TBQ) in primary care patients with multi-morbidity

Background. The Burden of Treatment Questionnaire (TBQ) assesses the impact of a patient's treatment workload on their quality of life Objectives. The aim was to translate and validate the TBQ on Chinese primary care patients with multi-morbidity. Methods. The English TBQ was translated and back-translated using professional translators. Cognitive debriefing interviews were performed on 15 patients. The resulting instrument was tested on 200 primary care patients with multi-morbidity (>1 chronic disease) to examine its psychometric performance including exploratory factor analysis, confirmatory factor analysis, internal consistency and reliability. The EuroQol Five-Dimension Five-Level Questionnaire (EQ-5D-5L), Short-Form Six-Dimension (SF-6D), WONCA COOP Charts and the Global Health Rating Scale were used to assess convergent and divergent validity. Results. Median age of the respondents was 62 years (range 22-95 years) with a median of four conditions. The median TBQ total score was 16 (interquartile range 7.25-30). There was a significant floor effect (>15%) observed for all items. Spearman's correlations was >0.4 for all items demonstrating adequate internal construct validity. TBQ global score correlated with number of conditions (P = 0.034), EQ-5D-5L (P < 0.001), SF-6D (P < 0.001) and the feelings (P = 0.004), daily activities (P = 0.003) and social activities (P < 0.001) domains of the WONCA COOP. There was no significant correlation between global health rating and TBQ global scores (P = 0.298). Factor analysis demonstrated a three-factor structure. There was good internal consistency (Cronbach's alpha = 0.842) and good test-retest reliability (intra-class correlation coefficient = 0.830). Conclusion. The newly translated Chinese version of the TBQ appears to be valid and reliable for use in Cantonese-speaking, adult primary care patients with multi-morbidity.