Table 4. Values of p* for between-group comparisons of the seven components and the global score of the Pittsburgh Sleep Quality Index.

Groups	COMPONENTS							Global score
	1st	2nd	3rd	4th	5th	6th	7th
A vs. B	0.59	0.19	0.70	0.21	0.68	0.78	0.10	0.37
A vs. C	0.40	0.90	0.53	0.65	0.19	0.37	0.05	0.10
B vs. C	0.19	0.26	0.73	0.09	0.37	0.22	0.74	0.37

A: first- and second-year students; B: third- and fourth-year students; and C: fifth- and sixth-year students. *Wilcoxon test for the components and Student’s t-test for the global score.