Reliability and validity of a brief patient-report instrument for psychiatric outcome evaluation.

Abstract

The authors describe the Behavior and Symptom Identification Scale (BASIS-32), a brief patient-report measure for psychiatric outcome assessment, and present the measure's factor structure and reliability and validity data. Using the BASIS-32, interviews were conducted with a total of 387 patients shortly after their admission to the adult inpatient services of a private not-for-profit psychiatric hospital. Six months after admission, they received a follow-up questionnaire version of the instrument. Factor analysis of the instrument yielded five factors, on which subscales were based: relation to self and others, daily living and role functioning, depression and anxiety, impulsive and addictive behavior, and psychosis. Internal consistency of the subscales ranged from .63 to .80. Internal consistency of the full 32-item scale was .89. Test-retest reliability ranged from .65 to .81 for the five subscales. Concurrent and discriminant validity analyses indicated that the BASIS-32 ratings successfully discriminated patients hospitalized six months after admission from those living in the community, patients working at follow-up from those not working, and patients with particular diagnoses. Follow-up ratings indicated that the BASIS-32 is sensitive to changes in symptomatology and functioning. The BASIS-32 provides a brief, standardized assessment of symptoms and problems from the patient's perspective. The instrument can be used for outcome assessment with most psychiatric inpatients.