The WHO Quality of Life (WHOQoL)-BREF

The short version of the WHO’s Quality of Life Instrument (WHOQoL-BREF) is widely validated and popularly used to assess the subjective QoL of patients and the general public [26]. To evaluate the criterion validity of the Chinese version of the PaArticular Scales, we used the Chinese version of the WHOQoL-BREF developed from the WHO’s WHOQoL group, which contains 26 items (Supplementary File 5). When the amount of missing data is large (greater than 10 %), the results of subsequent statistical analyses may be biased [27]. Therefore, questionnaires with more than 20 % missing data were discarded. Multiple imputation methods were used to manage missing data. If more than two values were missing in a domain, the domain score was not calculated (except for domain 3; the score was calculated only if the missing value was < 1).

For the Chinese version of the WHOQOL-BREF, Cronbach’s α coefficient for the internal consistency of the overall questionnaire ranged from 0.73 to 0.83, and the test-retest reliability coefficients of each category ranged from 0.41 to 0.79 [28]. The Pearson correlation between each item and its category ranged from 0.45 to 0.82 (p < .01), and the correlation between different categories ranged from 0.48 to 0.63 (p < .01). For the confirmatory factor analysis (CFA) of the construct validity, the structural equation model of the four factors replicates the potential structure designed by the questionnaire, and the comparative fitness indices (CFIs) of these two analyses had values of 0.886, which is equivalent to that of the Hong Kong version of the questionnaire (CFI = 0.894) and similar to that of the questionnaire using global data (CFI = 0.903) [28].