Validity Evidence and Normative Assessment of the Brief Adjustment Scale-6 in Brazil

Abstract Psychological adjustment (PA) reflects an individual’s capacity to adapt to environmental stressors by mobilizing responses that promote balance and well-being. This study evaluated the psychometric properties of the Brief Adjustment Scale-6 (BASE-6). The sample comprised 4,115 adults from all Brazilian states. Confirmatory factor analysis and measurement invariance testing were conducted, along with hierarchical linear and multinomial logistic regressions and correlations with external instruments (PHQ-9 and WHO-5) for validity testing. The results supported a unidimensional model with all fit indices exhibiting satisfactory values. The model remained invariant across sociodemographic variables at all assessment levels. Classification strata for PA (high, moderate, and low) were proposed based on score standardization. The results indicated lower levels of PA among women and younger participants. Overall, the findings support the use of BASE-6 as a brief and standardized screening measure of PA in Brazilian adults.