Table 1.

Sample characteristics (N = 200).

Variables	Mean (SD)/N (%)
Age in years	27.75 (5.11)
Male:Female (% of Female)	64:136 (68%)
Education
High school	23 (11.5%)
High diploma	22 (11.0%)
Bachelor’s degree	117 (58.5%)
Master’s degree	31 (15.5%)
Doctorate degree	7 (3.5%)
Consumption of caffeine beverages
Never	45 (22.5%)
Once per week	34 (17.0%)
2–3 times per week	55 (27.5%)
4–5 times per week	27 (13.5%)
More than 5 times per week	39 (19.5%)
Pittsburgh Sleep Quality Index (PSQI)
Global PSQI score	6.26 (2.88)
Subjective sleep quality	1.24 (0.70)
Sleep latency	1.03 (0.86)
Sleep duration	1.22 (0.91)
Habitual sleep efficiency	0.67 (1.01)
Sleep disturbance	1.12 (0.49)
Use of sleep medication	0.03 (0.17)
Daytime dysfunction	0.95 (0.77)
Morningness–Eveningness Questionnaire (MEQ)
MEQ score	48.48 (9.00)
MEQ subtypes
Morning type	27 (13.5%)
Intermediate type	130 (65.0%)
Evening type	43 (21.5%)
Connor–Davidson Resilience Scale (CD-RISC)
CD-RISC score	64.42 (11.56)
Depression Anxiety and Stress Scale (DASS)
Depressive symptoms score	5.04 (4.65)
Anxiety symptoms score	5.66 (3.94)