The Quality of Life Scale: An Instrument for Rating the Schizophrenic Deficit Syndrome

TLDR

Schizophrenia research increasingly focuses on deficit symptoms, yet current assessment tools mainly target productive symptoms. The study introduces the 21‑item Quality of Life Scale, a semistructured interview designed to assess deficit symptoms in schizophrenia. The authors present reliability data and training procedures for administering the QLS. Factor analysis confirmed the scale’s conceptual structure and showed similar results for men and women.

Abstract

There is growing interest in deficit symptoms in studies of the course and treatment response of schizophrenia. However, existing clinical assessment instruments focus primarily on productive symptoms. The authors describe the Quality of Life Scale (QLS), a 21-item scale based on a semistructured interview designed to assess deficit symptoms and thereby fill an important gap in the range of instruments now available. Data regarding reliability and training in the use of the QLS are presented. A factor analysis of the items yields results compatible with the conceptual model on which the scale is based. The factor analysis was also performed separately by sex and was fundamentally similar for men and women.