Table 1.

Mann-Whitney U test for gender and Kruskal-Wallis H test for grade (M ± SD)

	Mobile phone addiction	Bedtime procrastination	Physical exercise	Anxiety
Mann-Whitney U	1,320,595	1380599.5	1430591.5	1,327,696
Wilcoxon W	2,580,673	2640677.5	3225156.5	2,587,774
Z	-6.176	-4.199	-2.454	-5.973
Asymptotic significance (two-tailed)	< 0.001	< 0.001	0.014	< 0.001
chi-square (math.)	22.020	34.160	8.312	32.885
df	2	2	2	2
Progressive significance	< 0.001	< 0.001	0.016	< 0.001
Male	37.25 ± 16.47	3.27 ± 1.69	17.36 ± 19.21	5.30 ± 5.41
Female	32.94 ± 16.05	3.22 ± 1.71	18.65 ± 20.56	4.36 ± 4.90
first-year student	39.32 ± 13.91	3.29 ± 1.26	17.47 ± 18.79	4.98 ± 4.40
Sophomore	34.06 ± 17.05	3.28 ± 1.80	17.96 ± 20.15	4.87 ± 5.40
Junior	31.03 ± 15.03	3.17 ± 2.14	20.88 ± 20.93	4.00 ± 6.02