| bi-national evaluation of herbal product use on the united states/méxico border. | the study objective was to compare the prevalence of herbal product use between el paso, texas, and ciudad juárez, chihuahua, the largest u.s./méxico border population. 500 households on each side of the border were randomly selected following a strict procedure for household and participant selection. 1001 adult residents of selected households participated. trained bi-lingual interviewers conducted semistructured interviews using a bi-lingual questionnaire. a chi-square test was used to compar ... | 2007 | 18928136 |