Factorial structure of the Brief Symptom Inventory (BSI)-18 among Chinese drug users

Although the Brief Symptom Inventory-18 (BSI-18) has been widely used for mental health screenings in both clinical and non-clinical populations, the validation of its application to Chinese populations has been very limited. The objective of this research is to assess the factorial structure of the BSI-18 within a Chinese drug using population.

A total sample of 303 drug users recruited via Respondent Driven Sampling (RDS) from Changsha, China was used for the study. Our results show: (1) The BSI-18 item scores are highly skewed; (2) With dichotomous items measures (1 - problem at least moderately caused respondent discomfort during the past week; 0 - otherwise), our findings support the designed 3 - factor solution of the BSI-18 (somatization, depression, and anxiety); (3) The BSI-18 has a hierarchical factorial structure with 3 first-order factors and an underlying second-order factor (general psychological distress); (4) Tentative support should also be given to a single dimension of general psychological distress in Chinese drug using populations. Our study recommends a useful alternative approach for evaluating the factorial structure of the BSI-18 - i.e. CFA with dichotomous item measures. Both the total BSI-18 score and the three subscales (SOM, DEP, and ANX) can be used in applications of the BSI-18.

Overall, our findings suggest the BSI-18 is useful with Chinese drug users, and shows potential for use with non-Western and substance using populations more generally.