Factor structure of the Subjective Well-being under Neuroleptic treatment Scale-short form in schizophrenic outpatients: five factors or only one?

Reliability of a patient-reported outcome measure in schizophrenia: Results from back-to-back self-ratings

This study aimed to assess patient's capacity to perform a patient-reported outcome (PRO) measure (i.e., a self-rating scale) and examine its relationship with clinical characteristics including cognition. Fifty patients with schizophrenia were asked to rate the Subjective Well-being under Neuroleptics scale - Short form (SWNS) twice; the second rating was started immediately after they completed the first to minimize the gap between ratings. At the same time, the Positive and Negative Symptoms Scale (PANSS) and Brief Neurocognitive Assessment (BNA) were administered. The correlations between the two ratings for the SWNS total and each item scores were high (rs=0.94 and rs=0.60-0.84, respectively); however, for 16 (80%) of 20 items, 5 or more patients (i.e., ≥10%) demonstrated a>1 point score difference. There was no significant correlation between the SWNS total score difference and any clinical characteristics including age, education duration, illness duration, antipsychotic dose, psychopathology, and cognition. In contrast, the number of items with a>1 point score difference was significantly correlated with disorganized symptoms and overall severity (rs=0.29 for both), as well as working memory and global cognition (rs=-0.41 and rs=-0.40, respectively). These findings suggest that PROs should be interpreted with caution in patients with schizophrenia with prominent disorganization and cognitive impairment.

Cognitive function and risperidone long-acting injection vs. paliperidone palmitate in schizophrenia: a 6-month, open-label, randomized, pilot trial

BACKGROUND

Recently, long-acting injection (LAI) of second-generation antipsychotics has become a valuable strategy for the treatment of schizophrenia. However, few studies have compared the effects of different LAI antipsychotics on cognitive functions so far. The present study aimed to compare the influence of risperidone LAIs (RLAI) and paliperidone palmitate LAIs (PP) on cognitive function in outpatients with schizophrenia.

METHODS

In this 6-month, open-label, randomized, and controlled study, 30 patients with schizophrenia who were treated with RLAIs were randomly allocated to the RLAI-continued group or the PP group. At baseline and 6 months, the patients were evaluated using the Brief Assessment of Cognition in Schizophrenia (BACS) that was the primary outcome of the study. The Subjective Well-being under Neuroleptic drug treatment-Short form (SWNS), the Positive and Negative Syndrome Scale (PANSS), and the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) scores were secondary outcome variables and they were tested at the same time points.

RESULTS

The two groups did not differ in terms of PANSS, DIEPSS, or SWNS total score changes. However, the BACS score for the attention and processing speed item showed higher improvement in the PP group than the RLAI group (p = 0.039).

CONCLUSIONS

The results of this preliminary study suggest that PPs may improve attention and processing speed more than RLAIs. Anyway, a replication in a larger and double-blind study is needed.

TRIAL REGISTRATION

UMIN000014470 . Registered 10 July 2014.

Refinement of the SWN-20 based on the Rasch rating model

OBJECTIVES

The aim of the present study was to refine the 20-item Subjective Well-Being under Neuroleptic Treatment Scale (SWN-20) using the Rasch rating model to validate measurements of subjective well-being in patients with schizophrenia undergoing antipsychotic treatment.

METHODS

In total, 854 (403 males, 451 females) inpatients (n=213) and outpatients (n=641) with schizophrenia participated in this study, which was designed as an open-label investigation of paliperidone extended release. The participants completed the Korean version of the SWN-20 themselves. Refinement of the Korean version of the SWN-20 was accomplished using the Rasch rating model.

RESULTS

Infit and outfit statistics for all 20 items satisfied the criterion for construct validity. Second, all items except items 2 and 20 had suitable point-measure correlations, reflecting content validity. Third, item characteristic curves indicated that roughly 18 items were evenly distributed along the person ability continuum. Finally, option analysis of the category characteristics showed that categories 3 and 4 in the SWN-20 response format were unnecessary.

CONCLUSIONS

We offer several recommendations for improving the SWN-20: (a) items 2 and 20 should be omitted to ensure construct validity; (b) easier items would be added related to the person ability estimates in the process of validating a short form of the SWN scale based on item response theory; and (c) the number of response categories should be reduced for schizophrenic patients.