S37. CROSS-CULTURAL DIFFERENCES IN PANSS ITEM RATINGS: COMPARISONS OF SIX GEO-CULTURAL REGIONS
Authors: Crittenden Kia , Machizawa Sayaka , Todd Feaster H , Barbone Jordan M , Hong Bomi , Verma Prateek , Zhou Wei 
Published: May 2020

Background

While schizophrenia is observed in different parts of the world across countries, ethnicities, and races, research indicates cultural factors play significant roles in the phenomenology of this illness. Cultural norms and values affect manifestations of this pathology; more specifically, they affect how symptoms are expressed, experienced, and interpreted. Given that culture affects manifestations of schizophrenia, cultural factors should be considered in the assessment of its symptoms in clinical trials. This study explores the differences and patterns in the Positive and Negative Syndrome Scale (PANSS) item ratings across different geocultural regions. Identifying such patterns can give insights into culturally sensitive assessment practices and aid in developing more effective rater training and data surveillance that consider unique cultural factors.

Methods

Data were obtained from an international group of raters from 37 different countries, representing 6 geocultural regions across 13 different studies. As part of the rater training and qualification process for each of these studies, raters viewed and scored the 30-item PANSS based on a video-recorded PANSS interview that was administered using the Structured Clinical Interview-Positive and Negative Syndrome Scale (SCI-PANSS). Raters were deemed qualified if their scores fell within the defined acceptable item score ranges. Given the cultural diversity of the raters, the acceptable passing score ranges for each country were determined by a combination of expert opinion scores, group modal scores, and clinical analyses. Only the scores from raters who achieved qualification on their first scoring attempt were analyzed. The number of raters per geocultural regions included: Asia Pacific, n = 397; Eastern Europe, n = 412; Latin America, n = 88; Middle East/Africa, n = 29; North America, n = 339; and Western Europe, n = 129.

Results

A Shapiro-Wilk test for normality was conducted on the scores for each PANSS item and found all significantly different from a normal distribution (all ps &lt; .0001). A Kruskal-Wallis test for rank-ordered differences was conducted for each item for the influence of region on item score. Most items showed a significant influence of region on score after a Bonferroni correction was applied; most ps &lt; .0001 with the following exceptions: N1, p &lt; .001; G15, p &lt; .05; P2, P7, N6, N7, G1, G6, G10, G12, and G13 were not significant. The most significant cross-regional differences were found with P1, P3 and P6, and these items were analyzed further with a post hoc Dunn test to understand cross-regional patterns. On P1, Asia Pacific and Eastern Europe were significantly lower than Latin America, North America, and Western Europe (all ps &lt; .0008) but not Mideast/Africa. On P3, Western Europe were significantly lower than all other regions (all ps &lt; .0005); Asia Pacific were significantly lower than Eastern Europe, North America, and Western Europe (all ps &lt; .006). On P6, Asia Pacific and Eastern Europe were significantly lower than all other regions (all ps &lt; .03).

Discussion

The present study suggests that ratings of schizophrenia symptoms are influenced by cultural factors. Cultural beliefs and behaviors seem to influence interpretations of schizophrenia pathology. Given that the PANSS is not standardized for cross-cultural contexts, it is important to consider cultural factors when using this scale in clinical studies. In addition, when developing rater training and data surveillance programs, adjustment of acceptable item score ranges for key PANSS items highlighted above for different geocultural region is recommended. Future studies should explore country-level patterning of ratings of the PANSS.