Predictors of poor sleep quality among Lebanese university students: association between evening typology, lifestyle behaviors, and sleep habits

Figures & data

Table 1 Demographic and socioeconomic status of respondents

Variable	n	%§	Mean ± SD
Age (n=539), years
Males	266	49.4	20.08±1.61
Females	273	50.6	19.68±1.39
Educational level (n=461)
Sophomore	246	53.4
Junior	114	24.7
Senior	101	21.9
Employment status (n=538)
Employed	170	31.6
Looking for a job	64	11.9
Not employed	304	56.5
Socioeconomic status (n=509)
Low	56	11.0
Medium	402	79.0
High	51	10.0

Note:

§ Valid percentages are reported.

Abbreviation: SD, standard deviation.

Table 2 Personal lifestyle habits and sleep behavior of respondents

Variable	n	%§	Mean ± SD
Smoking cigarettes/narghile (n=539)
Yes	231	42.9
No	308	57.1
Smoking cigarettes (n=539)			Cigarettes/day: 12.74±10.30
Yes	111	20.6
No	428	79.4
Smoking narghile (n=533)			Narghile/month: 9.79±10.33
Yes	169	31.7
No	364	68.3
Study onset (n=497)
>12 am–6 am	15	3.0
>6 am–12 pm	130	26.2
>12 pm–6 pm	168	33.8
>6 pm–12 am	184	37.0
Bedtime
Weekdays (n=525)			12:10 am±83 min
Weekends (n=522)			1:39 am±100 min
Irregular bedtime between weekdays and weekends (n=516)
Yes	259	50.2
No	257	49.8
Nocturnal sleep duration, hours (SD) (n=496)
<6.5	61	12.3
6.5–8	197	39.7
>8	238	48.0

Note:

§ Valid percentages are reported.

Abbreviations: SD, standard deviation; min, minutes.

Figure 1 Mean nocturnal sleep duration (hours) on weekdays (left) and weekends (right) by chronotype. The weekend–weekday difference in sleep duration was significant in the E and N groups (P<0.001, Student’s t-test), but not the M group. When comparing the chronotype groups together, mean sleep duration was not significantly different between groups on weekdays, but was so on weekends (P=0.007, analysis of variance).

Note: *Significant difference in sleep duration among the chronotype groups on weekends.
Abbreviations: E, evening chronotype; N, neither type; M, morning chronotype.

Table 3 Variation of respondent sleep–wake habits and duration between weekdays and weekends with respect to circadian typology

	Chronotypes			F	P	η^2ρ
	Evening Mean ± SD	Neither Mean ± SD	Morning Mean ± SD
Wake-up time
Weekdays	8:33 am±90 min	7:44 am±82 min	7:04 am±62 min	19.494	<0.001*	0.086
Weekends	11:38 am±97 min	10:04 am±101 min	8:16 am±85 min	61.084	<0.001*	0.224
Bedtime
Weekdays	12:47 am±80 min	12:01 am±74 min	11:12 pm±87 min	23.023	<0.001*	0.098
Weekends	2:37 am±82 min	1:27 am±96 min	12:22 am±101 min	33.258	<0.001*	0.137
Sleep duration (hours)
Weekdays	7.78±1.48	7.67±1.48	7.86±1.12	0.419	0.658	0.002
Weekends	9.00±1.54	8.62±1.79	7.91±1.96	4.957	0.007*	0.023

Note:

* Significant difference in sleep/wake timing among chronotype groups on weekdays and weekends.

Abbreviations: SD, standard deviation; min, minutes.