Does Interviewer Status Matter? An examination of Lay Interviewers and Medical Doctor Interviewers in an Epidemiological Study in Vietnam.

In 2006, typhoon Xangsane disrupted a large-scale multi-agency mental health study of 4,982 individuals in the DaNang province of Vietnam. Following this disaster, 795 of the original 4,982 participants were randomly assigned to be re-interviewed by either a medical doctor or a lay interviewer using structured clinical interviews to determine prevalence of lifetime and post-typhoon post-traumatic stress disorder (PTSD), major depressive disorder (MDD), panic disorder (PD), and generalized anxiety disorder (GAD) according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (APA, 1994). The aim of the present study was to determine if prevalence of disorders differed by interviewer type. Bivariate analyses and multivariable analyses, as well as internal reliability estimates, all indicated no significant differences between the medical doctor interviewers versus the lay interviewers. This held for both lifetime prevalence as well as post-typhoon prevalence of disorders. This study has implications for epidemiologic studies, as it indicates that with adequate training, the use of lay interviewers may be a valid means of data collection.