The Family Burden Questionnaire (FBQ) is designed to measure treatment outcome in patients with psychotic disorders. Following an interview with the patient's key relative (i.e. a family representative significant and close to the patient) the questionnaire is filled out by the interviewer:
Aims – To analyse psychometric properties or the questionnaire and to establish its possible limitations.
Subjects – Three groups participated in validation of the tool: (1) 113 patients included in a program of evaluation of care provided by mobile community treatment teams; (2) 40 patients receiving inpatient treatment at the Institute of Psychiatry and Neurology, and (3) 32 representatives of the general population.
Method – The following properties of the questionnaire were assessed: (1) reliability (internal consistency, using the Cronbach α); (2) validity (a) theoretical validity (including an analysis of intergroup differences, a matrix of intercorrelation between items, and factor analysis), (b) diagnostic criterion validity (i.e. correlation between the FBQ score and scores on a social functioning scale); (3) test-retest stability (or susceptibility to change over time).
Results – The Cronbach a reliability coefficient was 82. The FBQ score turned out to significantly correlate with the level of the patient's social functioning. Family burden was significantly lower in families of patients participating in the community-based care evaluation program than in inpatients' families, at the same time being significantly higher than that in the general population. Two factors were found in the factor analysis: contrary to expectations, the first factor included 6 items, while the second one – only 2 items. During the 2 years of care pro vision by mobile community treatment teams the family burden has decreased by almost 40%.
Discussion – The study indicates that the questionnaire has satisfaction reliability, diagnostic criterion and theoretical validity, as well as test-retest stability. The instrument should be used as a single scale, since its present construction does not justify any separate subscales.
Conclusions – Psychometric properties of the FBQ are rather good and the too/may be used to evaluate treatment outcomes.