Abstract
Objectives: Assessment of psychopathological symptoms is an important part of research and clinical practice. This study examines the psychometric characteristics of the Czech version of the Brief Symptom Inventory (BSI-53 CZ) and forms the basis for creating standards for the Czech non-clinical population.
The BSI-53 is a shorter, multidimensional version of the Symptom-Checklist 90-R (SCL 90-R) questionnaire used to detect the presence of psychopathological symptoms. The instrument contains nine subscales and three general indexes: the Global Severity Index (GSI), Positive Symptom Total (PST) and Positive Symptom Distress Index (PSDI).
Sample and settings. A cross-sectional study on a representative sample of the adult Czech population (N=1800, mean age 46.4, SD 17.4, 48.7% men).
Statistical analyses were performed on the collected BSI-53 data. The Short-Form Health Survey (SF-8) was used to determine the convergent validity.
Results. Spearman's correlation coefficients between the BSI-53 subscales are moderately high, with values of 0.45-0.75.
Confirmatory factor analysis for a standard nine-factor model showed that loadings of all items on the associated factors were medium to high, with values of 0.55-0.87. This model shows a sufficient fit to our data: χ2 (1091)=4328.2, p<0.001, CFI=0.994, TLI=0.994, SRMR=0.045, RMSEA=0.041 (90%CI=0.039-0.042).
Internal consistency of the BSI-53 is high, with Cronbach's α=0.97 (95%CI 0.97-0.98) and Mc-Donald coefficients ωh=0.84 and ωt=0.97. The convergent validity, assessed by correlations with the mental health subscale of the SF-8 questionnaire, was found to be moderate to high.
Significant differences in the occurrence of psychopathological symptoms among different sociodemographic groups of the Czech population were found. Differences between the Czech data and data from several foreign countries (Germany, Great Britain and Israel) were found.
Conclusion. The BSI-53 questionnaire is a short, reliable instrument for the assessment of psychological distress.
The degree of utility of the instrument in clinical work and the evaluation of its potential to identify specific clinical syndromes and sensitivity to detect changes should be documented by further studies.