Background: There is little research on self-reported negative symptomatology measures in schizophrenia. The aims of this study were to validate the Spanish version of the Motivation and Pleasure Scale-Self-Report (MAP-SR) and determine the concordance between patient-reported outcome measures for reflecting the severity of negative symptoms of schizophrenia and clinician-rated outcome measures.
Method: A sample of 174 subjects who completed the MAP-SR and 104 who completed the Self-Evaluation of Negative Symptoms (SNS) were analyzed. The clinician-reported outcome measures (CROMs) were the Spanish versions of the Clinical Assessment Interview for Negative Symptoms (CAINS) and the Positive and Negative Syndrome Scale (PANSS), while the patient-reported outcome measures (PROMs) were MAP-SR and SNS. Cronbach's a, bivariate analyses and Lin's concordance correlation coefficient (CCC) were calculated.
Results: The Spanish version of the MAP-SR demonstrated excellent reliability (Cronbach's α=.923). Its correlation coefficients were higher with CAINS [CAINS-Total: r=.608, p<.005; CAINS-Motivation and Pleasure subscale(CAINS-MAP): r=.662, p<.005] than with PANSS negative scales [PANSS-Negative scale(PANSS-N): r=.393, p<.005; PANSS-Marder Negative Factor(PANSS-MNF): r=.478, p<.005]. Finally, concordance between clinician and patient ratings was low in all cases, varying from a CCC of 0.661 to .392.
Conclusions: We found poor concordance between patient and clinician ratings, hence we believe that the two evaluations are not mutually exclusive but complementary.