The study population consisted of 578 Thai-speaking individuals from a Hmong hill tribe village in Northern Thailand who were interviewed as part of a genetic linkage study of opioid dependence (OD). All subjects underwent diagnostic interviews using Thai versions of two clinician-administered rating scales adapted for the current study. Given prior estimates of reliability of the English instrument (Pierucci-Lagha et al., 2005), predictions of power, and issues of resources and time, 123 individuals among those initially enrolled participated in an inter-rater reliability substudy (a more conservative estimate of reliability that test-retest), comprised of two separate interviews conducted within a two-week period by different nurse interviewers who received specific training in both instruments.
