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Negative Symptom Dimensions of the Positive and Negative Syndrome Scale Across Geographical Regions: Implications for Social, Linguistic, and Cultural Consistency.

Publication ,  Journal Article
Khan, A; Liharska, L; Harvey, PD; Atkins, A; Ulshen, D; Keefe, RSE
Published in: Innov Clin Neurosci
December 1, 2017

Objective: Recognizing the discrete dimensions that underlie negative symptoms in schizophrenia and how these dimensions are understood across localities might result in better understanding and treatment of these symptoms. To this end, the objectives of this study were to 1) identify the Positive and Negative Syndrome Scale negative symptom dimensions of expressive deficits and experiential deficits and 2) analyze performance on these dimensions over 15 geographical regions to determine whether the items defining them manifest similar reliability across these regions. Design: Data were obtained for the baseline Positive and Negative Syndrome Scale visits of 6,889 subjects across 15 geographical regions. Using confirmatory factor analysis, we examined whether a two-factor negative symptom structure that is found in schizophrenia (experiential deficits and expressive deficits) would be replicated in our sample, and using differential item functioning, we tested the degree to which specific items from each negative symptom subfactor performed across geographical regions in comparison with the United States. Results: The two-factor negative symptom solution was replicated in this sample. Most geographical regions showed moderate-to-large differential item functioning for Positive and Negative Syndrome Scale expressive deficit items, especially N3 Poor Rapport, as compared with Positive and Negative Syndrome Scale experiential deficit items, showing that these items might be interpreted or scored differently in different regions. Across countries, except for India, the differential item functioning values did not favor raters in the United States. Conclusion: These results suggest that the Positive and Negative Syndrome Scale negative symptom factor can be better represented by a two-factor model than by a single-factor model. Additionally, the results show significant differences in responses to items representing the Positive and Negative Syndrome Scale expressive factors, but not the experiential factors, across regions. This could be due to a lack of equivalence between the original and translated versions, cultural differences with the interpretation of items, dissimilarities in rater training, or diversity in the understanding of scoring anchors. Knowing which items are challenging for raters across regions can help to guide Positive and Negative Syndrome Scale training and improve the results of international clinical trials aimed at negative symptoms.

Duke Scholars

Published In

Innov Clin Neurosci

ISSN

2158-8333

Publication Date

December 1, 2017

Volume

14

Issue

11-12

Start / End Page

30 / 40

Location

United States
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Khan, A., Liharska, L., Harvey, P. D., Atkins, A., Ulshen, D., & Keefe, R. S. E. (2017). Negative Symptom Dimensions of the Positive and Negative Syndrome Scale Across Geographical Regions: Implications for Social, Linguistic, and Cultural Consistency. Innov Clin Neurosci, 14(11–12), 30–40.
Khan, Anzalee, Lora Liharska, Philip D. Harvey, Alexandra Atkins, Daniel Ulshen, and Richard S. E. Keefe. “Negative Symptom Dimensions of the Positive and Negative Syndrome Scale Across Geographical Regions: Implications for Social, Linguistic, and Cultural Consistency.Innov Clin Neurosci 14, no. 11–12 (December 1, 2017): 30–40.
Khan A, Liharska L, Harvey PD, Atkins A, Ulshen D, Keefe RSE. Negative Symptom Dimensions of the Positive and Negative Syndrome Scale Across Geographical Regions: Implications for Social, Linguistic, and Cultural Consistency. Innov Clin Neurosci. 2017 Dec 1;14(11–12):30–40.
Khan A, Liharska L, Harvey PD, Atkins A, Ulshen D, Keefe RSE. Negative Symptom Dimensions of the Positive and Negative Syndrome Scale Across Geographical Regions: Implications for Social, Linguistic, and Cultural Consistency. Innov Clin Neurosci. 2017 Dec 1;14(11–12):30–40.

Published In

Innov Clin Neurosci

ISSN

2158-8333

Publication Date

December 1, 2017

Volume

14

Issue

11-12

Start / End Page

30 / 40

Location

United States