Development, reliability and validity of a self-administered questionnaire on subjective opinion about delusions and voices.

OBJECTIVE

This study focuses on the psychometric characteristics of a self-report instrument, the Delusion and Voices Self-Assessment (DV-SA) questionnaire, to assess delusions and auditory hallucinations from the clients' perspective.

METHODS

The DV-SA was administered to 70 schizophrenic patients in treatment in an outpatient mental health clinic in Naples, Italy. It was administered twice to determine the test-retest reliability. A clinician who was blind to the patients' DV-SA ratings also rated the Brief Psychiatric Rating Scale (BPRS). Sensitivity to change was assessed in 30 patients who completed a 24-week course of cognitive-behavioural therapy sessions.

RESULTS

The DV-SA showed good internal consistency and structure, and an acceptable average of item-total correlation. The test-retest reliability was very satisfactory. The comparison between DV-SA and BPRS showed a good association for illness severity.

CONCLUSIONS

The DV-SA may be a reliable, valid and sensitive instrument for assessing subjective experiences on delusions and auditory hallucinations. The brevity and limited need for assistance make it an efficient instrument to assess patients' evolution during therapy.