Cross-cultural adaptation and inter-rater reliability of the Schizophrenia proneness instrument adult version (SPI-A) in the Indonesian context

This study aims to adapt the Schizophrenia Proneness Instrument, Adult Version (SPI-A) for the assessment of basic symptoms to the Indonesian context (culturally and linguistically) and analyze the inter-rater reliability of the translated version. Following a specific methodology for cultural adaptation, direct and back-translations were conducted together with cognitive interviews to analyze the comprehensibility of the translated version. A linguistic expert analyzes the resulting version to determine its grammatical and linguistic adequacy. Finally, the interclass correlation (ICC) of the three expert ratings of the samples (N = 9) was analyzed. The direct and back-translation phases showed good conceptual equivalence to the original version. The cognitive interviews revealed items that were challenging to understand and required revision. The final version also considered the judgments of a linguistic expert for grammatical and conceptual improvements. Inter-rater reliability analysis showed an excellent degree of agreement (ICC value: 0.984; 95% CI: 0.950-0.996). The translated SPI-A fits the Indonesian context and can be used in clinical settings to assess basic symptoms in help-seeking individuals in Indonesia.