The reliability and validity of the outcome questionnaire

Abstract

With the rise in efforts to evaluate the quality of mental health care and its outcomes, the measurement of change has become an important topic. This paper tracks the creation of a new instrument designed to assess psychotherapy outcome. The Outcome Questionnaire (OQ) was designed to include items relevant to three domains central to mental health: subjective discomfort, interpersonal relations, and social role performance. This study describes the theoretical development and psychometric properties of the OQ. Psychometric properties were assessed using clinical, community, and undergraduate samples. The OQ appears to have high reliability and evidence to suggest good concurrent and construct validity of the total score. The data presented show that it distinguishes patient from non-patient samples, is sensitive to change, and correlates with other measures of patient distress. © 1996 by John Wiley & Sons, Ltd.