Background: The present study was conducted to translate and validate the World Health Organization's Quality-of-Life Scale - BREF into local language of Pakistan. Methods: A forward- backward translation procedure was followed to develop the Pakistani version of the questionnaire. Through a multi- stage clustered sampling technique, a sample of individuals aged 18 years and above completed the questionnaire in Abbottabad district, Pakistan. Psychometric properties of the instrument including reliability (internal consistency and test-retest analysis), validity (known group comparison and items' correlation) and their domains were assessed. Satisfactory results were also shown in the correlation matrix in all domains. Results: A total of 2060 participants were recruited in this study. Participants' mean age was 35.51 (SD= 14.31) years in healthy individuals and 39.29 (SD= 14.31) years in diseased individuals. The internal consistency of the WHOQOL-BREF (Pakistani Version) was 0.86. Moreover, the physical, psychological, and environmental domains had acceptable reliability (alpha= 0.78, 0.75, and 0.73, respectively), but reliability was low (alpha= 0.56) in the social domain. Reproducibility of the WHOQOL-BREF was as follows: ICC range: 0.72-0.92 at 2-week retest interval. After performing comparison analysis, the results indicated that the questionnaire significantly segregated the study groups in all QoL domains, except for social relationship. Conclusion: The study provided strong exploratory evidence for the reliability and validity of the WHOQOL-BREF for use in Pakistan. However, more exploration is needed to improve the reliability results in the social domain.
Keywords: Pakistan; Quality of life; Reliability; Validity; WHOQOL-BREF.