Innovations In Clinical Neuroscience

NOV-DEC 2017

A peer-reviewed, evidence-based journal for clinicians in the field of neuroscience

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69 ICNS INNOVATIONS IN CLINICAL NEUROSCIENCE November-December 2017 • Volume 14 • Number 11–12 C O M M E N T A R Y PANSS-6 contains the following six items that tap into the core positive and negative symptom dimensions of schizophrenia (and other psychotic disorders): Delusions, Conceptual Disorganization, Hallucinations, Blunted Affect, Passive/Apathetic Social Withdrawal, and Lack of Spontaneity and Flow of Conversation. This study showed that PANSS-6, as opposed to the full 30-item version of PANSS, is "scalable," which means that each item adds unique information regarding severity and that the total score is therefore a valid measure of severity (Figure 1). 13 Furthermore, this study showed that PANSS-6 is sensitive to changes in the severity of schizophrenia and can separate the effects of typical and atypical antipsychotics from that of placebo (Figure 2). 7 PANSS-6 AND CATIE Since the initial study on PANSS-6 7 was based on data from trials in which the participants were acutely ill hospitalized patients with schizophrenia, 11,12 we went on to assess the psychometric properties of PANSS-6 in chronic schizophrenia via a reanalysis of data from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study. 14 The results of the analysis of the data from CATIE confirmed those from our study in acutely ill patients, namely that PANSS-6 adequately measures symptom severity and antipsychotic efficacy in schizophrenia (Figures 3 and 4). 8 Furthermore, this study also established that PANSS-6 can identify symptom remission as defined by the Andreasen et al. expert consensus criteria 15 with very high accuracy. 8 SNAPSI Our findings so far suggest that PANSS-6 has the qualities to bridge between research and clinical practice for the following reasons: 1) PANSS-6 has content validity, as it is based upon an expert consensus definition of severity/remission 15 and covers core symptoms of schizophrenia; 16 2) As opposed to the full 30-item version of PANSS, PANSS-6 is "scalable," which means that each item adds unique information regarding severity, and the total score is therefore a valid measure of severity; and 3) PANSS-6 is sensitive to changes in the severity of core positive and negative schizophrenia symptoms and can FIGURE 1A–B. A) Illustration of a hypothetical six-item rating scale, which is scalable because the symptoms represented by the items appear in an orderly fashion as the severity of the syndrome increases, such that scoring on higher prevalence items (less severe items) precedes scoring on lower prevalence items (more severe items). Thus, when an outcome measure is scalable, each individual item adds unique information about the severity of the latent syndrome being rated and the individual item scores can therefore be added to a meaningful total score. B) Illustration of the scalability of the Positive and Negative Syndrome Scale-6 (PANSS-6) based on the Rasch locations at baseline—This figure and the figure text is reproduced from Ostergaard et al. 7 with permission from the publisher via RightsLink. FIGURE 2. Positive and Negative Syndrome Scale-6 (PANSS-6)'s sensitivity to change in the severity of illness during treatment. Change in PANSS-6 scores by treatment based on data from Zimbroff et al. 12 Statistics: analyses of covariance of mean change from baseline including the baseline score as covariate. *p<0.05, **p<0.01, ***p<0.001. This figure and the figure text is reproduced from Østergaard et al. 7 with permission from the publisher via RightsLink. 1A 1B

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