What is hidden in my data? Practical strategies to reveal Yule-Simpson's paradox and strengthen research quality in health education research.

Yule-Simpson's paradox (YSP) often occurs when statistical data are aggregated from multiple groups, research sites, or time points. If YSP-type effects go unrecognized, health educators risk yielding erroneous and spurious findings or misinterpreting study data. These paradoxical effects may be avoided if health researchers carefully consider strategies to avoid YSP at the onset of and throughout research studies. This article presents strategies to reduce or avoid YSP-type effects across multiple stages of the research process. A practical checklist is also provided to minimize the likelihood YSP will go unnoticed in research studies.