Internal Consistency and Convergent Validity of the Portuguese Versions of the Global Appraisal of Individual Needs-Initial and Short Screener: Validity of the Portuguese GAIN-I and SS.

The goal of this article is to present evidence on the internal consistency and convergent validity of the Brazilian Portuguese versions of the Global Appraisal of Individual Needs-"Initial" and "Short Screener" versions. METHODS: One hundred sixty-eight individuals from an inpatient service and/or a community-based outpatient service located in São Paulo were interviewed using the Brazilian Portuguese versions of the instruments. The internal consistency of the instruments scales was computed, along with evidence for the convergent validity between corresponding subscales of the Initial and Short Screener instruments. RESULTS: Cronbach's alpha values for both instruments' total scale scores were greater than .7. The Short Screener scales showed strong-to-moderate correlations with corresponding subscales of the Initial. The General Individual Severity Scale from the Initial and Total Disorder Screener from the Short Screener have convergent validity with each other (ρ = 0.801). CONCLUSIONS: The Brazilian Portuguese instrument scales showed evidence for internal consistency and convergent validity performing similarly to the American English versions.

Rasch model of the GAIN substance problem scale among inpatient and outpatient clients in the city of São Paulo, Brazil.

INTRODUCTION: This study used the Rasch model to evaluate the psychometric properties of the Portuguese version of the Substance Problem Scale (SPS) of the "Global Appraisal of Individual Needs - Initial" for use in Brazil. The SPS measures alcohol and drug problem severity within a DSM-IV-TR framework. The goal of the Rasch analysis was to assess scale dimensionality, item severity, and differential item functioning (DIF). METHODS: Data was collected from 40 inpatients and 70 outpatients in São Paulo, Brazil. The Rasch model fit and DIF by gender and level of care were examined. RESULTS: The SPS fit the Rasch model, with no items distorting the measure. Only three of the sixteen items performed differently between men and women and three performed differently by level of care. CONCLUSIONS: The results were compatible with those from Rasch analyses of the American English and Canadian English versions of the scale. The Portuguese version of the SPS is, thus, valid for use in Brazil, both with men and women in inpatient and outpatient programs.

•Rasch analysis of the Portuguese version of the Substance Problem Scale performed•This scale has performance similar to Canadian and American versions.•None of the scale items distort the measurement.•Further differential item functioning analysis with larger sample needed.