The purpose of this study was to compare the sensitivity of four generic effectiveness measures with clinically meaningful symptom improvement in persons with schizophrenia.
Baseline and 6-month interviews were conducted with 134 subjects diagnosed with schizophrenia or schizoaffective disorder. The design was observational. The four generic effectiveness measures included the Quality of Well-Being scale (QWB), a quality-adjusted index score based on the SF-36 VAS, Veterans SF-36 mental health component summary score (MCS), and the World Health Organization Disablement Assessment Schedule (WHO-DAS). Symptom measures included the Positive and Negative Syndrome Scale (PANSS) and Calgary Depression Scale (CDS). The side effect measure was the Extrapyramidal Symptom Rating Scale (ESRS). Data analysis included correlations between symptom, side effect, and generic effectiveness change scores; and an effect size calculation to detect a clinically significant improvement in the total PANSS.
All four effectiveness measures were correlated with changes in side effects. All but the SG-36 VAS were correlated with changes in depression. Only the QWB was correlated with changes in PANSS scores. The QWB required at least three times fewer subjects (n = 61) to detect a clinically significant improvement in total PANSS compared with the other effectiveness measures (n = 201–324).
It is recommended that clinicians and researchers use the QWB to demonstrate the effectiveness and cost-effectiveness of schizophrenia interventions. The QWB allows for direct comparison of the effectiveness and cost-effectiveness of schizophrenia interventions with other mental and physical health interventions and may contribute to a greater recognition of the value of mental health interventions.
*From the South Central VA Healthcare Network, and the Department of Psychiatry, Central Arkansas Veterans Healthcare System, the University of Arkansas for Medical Sciences, Little Rock, Arkansas.
†From the Department of Family and Preventive Medicine, University of California San Diego, La Jolla, California.
‡From the Department of Biometry, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
Supported by a VA Career Development Award from the Department of Veterans Affairs Health Services Research & Development Service (Grant #CD-97310-2) and the South Central (VISN 16) MIRECC.
An earlier version of this work was presented at the 2001 APA Annual Meeting, New Orleans, LA.
Address correspondence and reprint requests to: Jeffrey M. Pyne, MD, Central Arkansas Veterans Healthcare System, Department of Psychiatry, 116F2/NLR, 2200 Fort Roots Drive, North Little Rock, AR 72114. E-mail: firstname.lastname@example.org
Received January 9, 2002; initial review March 15, 2002; accepted July 16, 2002.