Measurement and data analysis in research addressing health disparities in substance abuse.

This article describes concrete strategies for conducting substance abuse research with ethnic minorities. It addresses two major issues associated with valid analysis: measurement and data analysis. Both empirical (e.g., confirmatory factor analysis, item response theory, and regression) and nonempirical (e.g., focus groups, expert panels, pilot studies, and translation equivalence) approaches to improve measures are described. A discussion of the use of norms and cutoff scores derived from a different ethnic group along with the effects of the ethnicity of the interviewer or coder on measurement is also included. The diversity represented in large, multisite clinical trials such as the National Drug Abuse Treatment Clinical Trials Network (CTN) is cited as a tremendous opportunity to address a number of important issues beyond the original purpose of the data sets, such as whether treatments work differently for specific subgroups of an ethnic minority group or whether the mechanisms of how treatments work are different for specific ethnic groups. The article also contains a section on data analysis that describes why the use of race-comparison designs may lead to misleading conclusions. Alternatives to race-comparison analysis including within-group and between-group analyses are detailed, as well as the shortcomings of combining ethnic groups for analyses. The article ends with a list of recommendations for research with ethnic minorities.