Capturing trafficking trauma: A proposed measure using principal component analysis

Trafficked individuals often exhibit mental health problems due to the multiple abuses they experienced while trafficked. Prior research has mostly examined the mental health effects of specific types of abuses (usually, sexual, physical, and emotional abuse). This analytical design ignores the likely different and more complex psychological sequelae of multiple traumas as compared to individual traumas, and thus may limit our understanding of the psychological impact of human trafficking.

Using cross-sectional pilot data (n=73) from a post-trafficking project in Vietnam, we: (1) describe a method of computing a composite measure of trafficking trauma using principal component analysis (PCA); and (2) discuss the relationship between this measure of trafficking trauma and psychological symptoms, assessed via the 20-item Self-Reporting Questionnaire (SRQ), and compared these results to those of selected individual abuses.

We assessed 18 (yes/no) items of abuse that are characteristic of the trafficking experience. We used exploratory factor analysis (EFA) to derive a parsimonious, reduced set of items, and then used factor loadings from the PCA of the reduced set to compute a composite Trafficking Abuse Score (TAS). Ordinary least squares regression analyses were used to examine the association between SRQ score and TAS as well as some individual abuses.

Findings from EFA yielded a 5-item set (physical-, emotional-, labor-, sexual abuse, and forced alcohol use) that had good reliability (ɑ=0.864). Participants’ Trafficking Abuse Score averaged at 1.58 (SD=1.46, range 0–3.71) and SRQ Score 8.3 symptoms (SD=4.2, range 0–20). Linear regression results showed that the associations between individual abuses and psychological symptoms varied, and that TAS was positively associated with SRQ Score (β=1.213; 95% CI 0.60–1.82).

The PCA-derived composite measure of trafficking trauma presented in this study accounts for the likely interactive effects of the multiple abuses that trafficked individuals experience. This and similar techniques should be explored in other studies, so that we can more comprehensively assess the trauma and its health consequences among trafficked populations.