Table 2.

Comparison of the groups in terms of the PIU score (continuous variable)

Variables	df	χ² and Z scores	p value
Sex^a		z = –2.52^a	< *0.05*
Study mode (full time/extramural)^a		z = –2.98^a	< *0.01*
Study cycle (bachelor, master, uniform)^b	2	χ² = 8.65^b	< *0.05*
Year of studies^b	3	χ² = 4.09^b	NS^f
Field of studies^b	9	χ² = 32.44^b	< *0.001*
Preferred device (computer/smartphone/computer and smartphone comparably)^b	2	χ² = 11.34^b	< *0.01*
Purpose of Internet use^b	5	χ² = 29.35^b	< *0.001*
Severity of IZZ^{b, c}	2	χ² = 7.26^b	< *0.05*
BDI risk category^{a, d}		z = –5.01^a	< *0.001*
EAT risk category^{a, e}		z = –1.17^a	NS

^aMann–Whitney U test

^bKruskal–Wallis test

^cIZZ severity—groups of low, medium and high frequency of health-related behaviors

^dBDI risk category—comparison of groups which meet and do not meet diagnostic criteria for a depressive episode

^eEAT risk category—comparison of groups which meet and do not meet diagnostic criteria for eating disorders

^fnot statistically significant