Illness perception in Polish patients with chronic diseases: Psychometric properties of the Brief Illness Perception Questionnaire.

The study evaluates the psychometric properties of a Polish translation of the Brief Illness Perception Questionnaire. A total of 276 patients with chronic conditions (58.7% women) completed the Brief Illness Perception Questionnaire and the Hospital Anxiety and Depression Scale. The internal consistency of the Polish Brief Illness Perception Questionnaire measured with Cronbach's alpha was satisfactory (α = 0.74). Structural validity was demonstrated by significant inter-correlations between the Brief Illness Perception Questionnaire components. Discriminant validity was supported by the fact that the Brief Illness Perception Questionnaire enables patients with various conditions to be differentiated. Significant correlations were found between Brief Illness Perception Questionnaire and depression and anxiety levels. The Polish Brief Illness Perception Questionnaire thus evaluated is a reliable and valid tool.