Please consider part A and B 5000 subjects completed a lifes

Please consider part A and B:

5,000 subjects completed a lifestyle modification program about changing eating habits and increasing exercise. The article reports that after the intervention the mean difference in weight before and after the intervention is 0.02 kg with p-value=0.001 from a paired t-test.

a.Is this finding statistically significant? Justify your answer

b.Is this finding clinically significant? Justify your answer.

Solution

statistically significant -> yes, the p-value is very small (less than 0.05), and thus this difference is statistically significant.

The mean difference of 0.02 kg might not be clinically significant, we need the actual sample means along with standard deviations in order judge if the intervention made a clinical difference.