Cross-cultural use of the predetermined scale cutoff points in refugee mental health research

Background Cross-cultural use of the cutoff points determined in Indo-Chinese refugees of the Hopkins Symptom Checklist-25 (HSCL-25) and the Harvard Trauma Questionnaire (HTQ) is common in refugee mental health research but it might have caused misclassifications. Methods We assessed the validity of the predetermined cutoff points in identifying depression and post-traumatic stress disorder (PTSD) cases among Afghan refugees, with the algorithm method as a gold standard. We estimated the prevalence of depression and PTSD, using the HSCL-25 and the HTQ with the cutoff points and the algorithm method, and calculated sensitivity, specificity, positive and negative predictive values of the cutoff points. Results Nine in ten PTSD cases/noncases were correctly identified as cases/non-cases, and nine in ten respondents classified as PTSD cases/noncases were actually cases/non-cases. In contrast, only one in three non-depression cases was correctly identified as a non-case, and three in five respondents who were classified as depression cases was actually a case. The prevalence of depression was estimated to be 86% with the cutoff points and 53% with the algorithm method, and that of PTSD 46% and 44%, respectively. Conclusions The cutoff point approach might have low specificity and positive predictive value particularly for depression in our study. Cross-cultural use of the scale cutoff points determined in one cultural group to another needs to be reconsidered.