Abbreviated quality of life scales for schizophrenia: Comparison and utility of two brief community functioning measures Gagan Fervaha a,b, ⁎, George Foussias a,b,c , Ishraq Siddiqui a,b , Ofer Agid a,b,c , Gary Remington a,b,c a Schizophrenia Division, Centre for Addiction and Mental Health, Toronto, Canada b Institute of Medical Science, University of Toronto, Toronto, Canada c Department of Psychiatry, University of Toronto, Toronto, Canada abstract article info Article history: Received 6 January 2014 Received in revised form 14 February 2014 Accepted 17 February 2014 Available online 11 March 2014 Keywords: Schizophrenia Abbreviated Quality of Life Scale Functional outcome Psychosocial functioning Avolition-Apathy Clinical assessment tool Background: The Heinrichs-Carpenter Quality of Life Scale (QLS) is the most extensively used real-world commu- nity functioning scale in schizophrenia research. However, the extensive time required to administer it and the inclusion of items that overlap conceptually with negative symptoms limit its use across studies. The present study examined the validity and utility of two abbreviated QLS measures against the full QLS excluding negative symptom items. Method: The sample included 1427 patients with schizophrenia who completed the baseline visit in the CATIE study. The validity of two abbreviated QLS measures (7-item and 4-item) were examined with the full QLS, ex- cluding the intrapsychic foundations subscale, using correlation analysis. The utility of the abbreviated measures was explored by examining associations between the functioning scales and clinical variables and longitudinal change. Results: Both abbreviated QLS measures were highly predictive of the full QLS (both r = 0.91, p b 0.001), with no difference in predictive value between the abridged measures. Functional status was significantly associated with symptoms and cognition. Importantly, the strength of these associations was similar between the abbreviated and full QLS. Finally, multiple regression models examining the explanatory power of amotivation/apathy in predicting functioning scores after other symptoms and neurocognition had been accounted for were essentially identical irrespective of the QLS instrument used as the dependent measure. Longitudinal change was also similar across the three scales. Conclusions: The 7-item abbreviated QLS is recommended as a brief measure of community functioning for indi- viduals with schizophrenia, especially when assessment of functional outcome is not the focus. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Real-world community functioning is increasingly embraced as an important outcome for individuals with schizophrenia. While nu- merous instruments have been developed to assess functional out- comes in schizophrenia, the Heinrichs-Carpenter Quality of Life Scale (QLS; Heinrichs et al., 1984) has been the most extensively employed in schizophrenia research (Leifker et al., 2011), a feature highlighted by the inclusion of this scale in two large antipsychotic effectiveness trials (Lieberman et al., 2005; Jones et al., 2006). The QLS is a rater-administered 21-item semi-structured interview instrument, which is comprised of four subscales: interpersonal rela- tions, instrumental role functioning, intrapsychic foundations, and use of common objects and activities. Though the QLS is a comprehensive instrument which assesses social, vocational and everyday living skills, it also includes items within the intrapsychic foundations subscale that overlap conceptually with negative symptoms and therefore may not assess community functioning per se (Harvey, 2013). Moreover, the extensive time required to administer the scale (approximately 45 minutes) limits its applicability in clinical practice and across re- search studies, especially when functioning is not the focus. To sidestep this latter issue, shortened versions of the QLS have been developed that take much less time to administer yet are able to validly estimate total scores (Bilker et al., 2003; Fervaha and Remington, 2013); however, the validity of this shortened scale has been established against the 21-item QLS which includes the intrapsychic foundations subscale. Given recent recommendations to exclude this subscale from the QLS when assessing functional outcome (Harvey, 2013), as well as the need for shortened instruments in outcome research, we sought to examine the validity and utility of two abbreviated QLS' against the full QLS (excluding intrapsychic foundations). Specifically, the two Schizophrenia Research 154 (2014) 89–92 ⁎ Corresponding author at: Schizophrenia Division, Centre for Addiction and Mental Health, 250 College Street, Room 320, Toronto, Ontario M5T 1R8, Canada. Tel.: +1 416 535 8501x34818; fax: +1 416 979 4292. E-mail address: gagan.fervaha@utoronto.ca (G. Fervaha). http://dx.doi.org/10.1016/j.schres.2014.02.013 0920-9964/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Schizophrenia Research journal homepage: www.elsevier.com/locate/schres