Psychometric evaluation of an interview-administered version of the WHOQOL-BREF questionnaire for use in a cross-sectional study of a rural district in Bangladesh: an application of Rasch analysis.

BACKGROUND: This study aimed to validate the psychometric properties of the World Health Organization Quality of Life Instrument, Short Form (WHOQOL-BREF) questionnaire for use in a rural district of Bangladesh. METHODS: This cross-sectional study recruited a multi-stage cluster random sample of 2425 participants from the rural district Narail of Bangladesh in May-July 2017. Rasch analysis was carried out using the sampled participants, as well as multiple validation random sub-samples of 300 participants, to validate four domains of the WHOQOL-BREF questionnaire: physical, psychological, social and environmental. RESULTS: The original WHOQOL-BREF appeared to be a poor fit for both sampled and sub-sampled group of participants in Narail district in all underlying domains: physical, psychological, social and environmental. Two items (sleep and work capacity) from the physical domain, two items (personal belief and negative feelings) from the psychological domain and three items (home environment, health care and transport) from the environment domain were excluded for goodness of fit of the Rasch model. The social domain exhibited reasonably reliable fitness while fulfilling all the assumptions of the Rasch model. A modified version of the WHOQOL-BREF questionnaire using five-items for the physical ([Formula: see text] = 36.47, p = 0.013, Person Separation Index (PSI) = 0.773), four-items for the psychological ([Formula: see text] = 28.30, p = 0.029, PSI = 0.708) and five-items for the environmental ([Formula: see text] = 36.97, p = 0.011, PSI = 0.804) domain was applied, which showed adequate internal consistency, reliability, unidimensionality, and similar functioning for different age-sex distributions. CONCLUSIONS: The modified WHOQOL-BREF questionnaire translated into Bengali language appeared to be a valid tool for measuring quality of life in a typical rural district in Bangladesh. Despite some limitations of the modified WHOQOL-BREF questionnaire, further application of Rasch analysis using this version or an improved one in other representative rural areas of Bangladesh is recommended to assess the external validity of the outcomes of this study and to determine the efficacy of this tool to measure the quality of life at the national rural level.