Table 2.

Participants’ chronotypes 

	Chronotypes			p-value	Chi-Squared Statistic	Degrees of Freedom	Cramer’s V
	Morning	Intermediate	Evening
Chronotypes of participants, n (%)	134 (26.7)	306 (60.5)	100 (12.7)
Poland, n (%)	16 (24.6)	31 (47.7)	18 (27.7)	<0.01	59.8	6	0.24
Russia, n (%)	83 (24.3)	214 (62.7)	44 (13.0)
Australia, n (%)	20 (66.6)	8 (26.7)	2 (6.6)
Japan, n (%)	15 (14.4)	53 (50.9)	36 (34.6)

Students (n = 540) were categorized into morning types, n = 134; intermediate types, n = 306; and evening types, n = 100. Data were analyzed with Chi-square test and with Cramer’s V for chi squared test

A value of p < 0.05 was considered as significant