Developing an instrument to study the tuberculosis screening behaviors of Mexican migrant farmworkers

This article details the use of qualitative data in the construction of a Spanish-language, quantitative research instrument designed for a study of Mexican migrant farmworkers' participation in tuberculosis screening. In the qualitative study, 19 Mexican migrant farmworkers were interviewed in Spanish to elicit their explanatory models (EMs) about tuberculosis. The Tuberculosis Interview Instrument (TII) was developed from the results of the qualitative study and concepts from a theoretical framework consisting of a combination of the Health Belief Model (HBM) and the Theory of Reasoned Action (TRA). After its development, the TII was subjected to translation and back-translation procedures to insure the equivalency of the English and Spanish versions, and it was reviewed for content validity. Internal consistency reliability, based on the responses of 206 subjects, was satisfactory for all subscales. Future testing of the TII is recommended to evaluate its stability among Mexican migrant farmworkers in other parts of the United States.