Development and verification of validity and reliability of the WHOQOL-BREF Taiwan version

The World Health Organization (WHO) initiated a cross-cultural project to develop the World Health Organization Quality of Life (WHOQOL) questionnaire. This paper describes how the brief version of this questionnaire was adapted for use in Taiwan and the results of validity and reliability testing.

Data were collected from 1,068 subjects randomly sampled from 17 hospitals throughout Taiwan. According to the psychometric criteria of the WHO, two (culturally relevant) national items were selected, each from a culture-specific facet that was proposed for Taiwan in a previous study. psychometric properties (factor structures and various types of reliability and validity) were assessed for this brief questionnaire.

Exploratory and confirmatory factor analyses revealed a four-factor (physical, psychological, social, and environmental) model. The internal consistency (Cronbach's alpha) coefficients ranged from 0.70 to 0.77 for the four domains. The test-retest reliability coefficients with intervals of 2 to 4 weeks ranged from 0.41 to 0.79 at item/facet level and 0.76 to 0.80 at domain level (all p < 0.01). Content validity coefficients were in the range of 0.53 to 0.78 for item-domain correlations and 0.51 to 0.64 for inter-domain correlations (all p < 0.01). The four domains of the brief form can explain 88% of the variance of the total QOL score and 60% of the variance of the Facet G score (measuring overall quality of life and general health).

This culture-specific study shows that this adaptation of the brief form is a good alternative to the long form of the WHOQOL questionnaire for use in Taiwan.