Psychometric properties of the Turkish Version of the Brief Quality of Life in Bipolar Disorder (Brief QoL.BD) Scale

Abstract

Objectives: The aim of this study was to determine the reliability and validity of the Turkish version of the Brief Quality of Life in Bipolar Disorder Scale [QoL.BD]. Methods: Conducted using a methodological and identifying design, this study included 76 patients who had been diagnosed with bipolar disorder and from whom the data was obtained in 2013. Patients from the mood disorders centers of two different psychiatry clinics constituted the population of the study. The Turkish version of the Brief QoL.BD was assessed in terms of language, content, and structure in the sample of 76 patients diagnosed with bipolar disorder. Lawshe's methods were used to assess content validity; exploratory factor analysis was used to determine latent structure; and Cronbach's internal consistency coefficient was used to test internal reliability. Results: The study included 76 patients diagnosed as bipolar I and II. Content validity of the 12-item scale was found to be strong (Lawshe index =.82), as was the internal reliability of the scale [alpha =.86]. Factorability of the correlation matrix was confirmed, and a single factor extraction was suggested on the basis of the scree plot and Velicer's minimum average partial test. This single factor explained 36.05% of the variance, with all items having positive loadings and six items having factor loadings >.3. Conclusion: The Turkish version of the Brief QoL.BD was concluded to have adequate internal reliability and validity for assessing disorder-specific quality of life in euthymic patients with bipolar disorders.