The categorical example shown above suggests that there is a statistically significant difference for changes in resting systolic blood pressure when outcomes were partitioned according to the country in which the study was conducted. However, there was no statistically significant difference between types of trials (See Kelley GA, Kelley KS. Aerobic exercise and resting blood pressure in women: a meta-analytic review of controlled clinical trials. Journal of Women's Health & Gender-Based Medicine 8:787-803, 1999).