The current study showed that self ratings
The current study showed that self-ratings with the SFS could predict total working hours in recent months. Self-reports have sometimes been considered to be less reliable compared to performance-based assessment or informants’ observations, partly due to poor insights of patients (for a review, Bellack et al., 2007; Durand et al., in press). It might be concerned that work hours in the current study was obtained by self-report, which could induce a biased association with the self-rated scores in the SFS (i.e. both measures might have been over-estimated). The possibility could be excluded by several reasons. First, it has been shown that patients and informants ratings on the SFS were highly correlated (Dickerson et al., 1997). Second, the SFS ratings have been reported to be correlated with those of the SLOF, which is an informant-based objective measure (Sumiyoshi et al., unpublished data). Third, as shown in the regression analyses, a performance-based measure of the MCCB (Learning/Emotional management component) remained as a significant factor to predict work hours and status, providing an objective support for the accuracy of the self-report on work hours. To further examine this issue, we conducted a supplementary regression analysis assuming that at least one of the performance measures (either the MCCB or the UPSA-B) would certainly contribute to prediction of work hours in patients with schizophrenia. This time, predicting variables were the MCCB Overall composite score, the SFS Total score, and UPSA-B Total score were directly regressed on work hours in recent 3 months using a forced-enter method. As a result, the model was significant (F=7.78, df=3, 41, p <0.01), accounting for 31.4 % of the total variance for work hours (=0.31). The most T-5224 predictor was the SFS total score (β=0.52, t=4.30, p < 0.01), followed by the MCCB Overall composite score (β=27, t=1.98, p=0.05). The UPSA-B Total score was at a trend level only (p=0.07). Although the partial coefficient of the MCCB was near to marginal significance, the result confirmed the contribution of the performance-based measure to prediction of work hours, validating the self-evaluation in the current study. Several limitations should be noted. First, the sample size of plasma cells study was relatively small. Latent predictors might have become significant in the regression analyses with a larger number of patients. Second, we did not include variables related to psychiatric symptoms, which have been shown to affect work outcome (Bowie et al., 2010; Bowie et al., 2008; Bowie et al., 2006; McGurk and Mueser, 2004). Future studies will be aimed to address these issues.
Role of Funding Source This work was supported by Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Scientific Research (C) No. 22530691 to CS and No. 26461761 to TS7, as well as Health and Labour Sciences Research Grants for Comprehensive Research on Disability, Health, and Welfare (H24-Seishin-Ippan-002 and H26-Seishin-Ippan-011) and Intramural Research Grant for Neurological and Psychiatric Disorders of NCNP (21-1) and (27-1) to TS7.
Contributors CS and PH designed the study. TS7 and IS supervised the study. CS, MT, YO, and TS7 collected data. KS and TS4 prepared materials. CS analyzed data, and wrote the draft. TS7, PH, and MT revised the draft critically for important intellectual content. All authors contributed to manuscript writing.
Conflict of interest
Introduction Cognitive deficits in schizophrenia are related to functional outcomes, as shown in both cross-sectional (Fett et al., 2011; Green et al., 2000; Ventura et al., 2009) and longitudinal studies (Allott et al., 2011; Green et al., 2004; Ventura et al., 2011). However, some studies have failed to confirm this relationship (e.g. Addington et al., 1998; Johnstone et al., 1990; Verdoux et al., 2002). The association between neurocognition and clinical outcomes is not equally well documented. Patients with greater neurocognitive ability have a higher likelihood of achieving (Helldin et al., 2006; Kopelowicz et al., 2005) and remaining in remission (Holthausen et al., 2007), though other studies have failed to show an association between neurocognition and clinical outcomes (Buckley et al., 2007; Li et al., 2010; Robinson et al., 1999).