1. To show causality, researchers must use a/an ______________ study design.
2. The Texas Men’s Health Study enrolled 38,649 men in 1999 and collected exposure and lifestyle information to assess the relationship between these factors and subsequent occurrence of heart disease, is an example of which type of study?
3. Clinical trials occur under very specialized, controlled conditions that do not represent everyday life. Generalizing the results obtained in this environment to populations not engaged in the research is a concern for this type of study.