Table 1.

Sleep duration and quality by independent variables (n = 18,211).

Variable	n	Sleep Duration (n = 17845) 1		Sleep Quality-Problem (n = 17875) 2
		6 or Less	9 or More	Mild	Moderate	Severe/Extreme
		M (SD)	M (SD)	M (SD)	M (SD)	M (SD)
Sociodemographics
Age (in years)	18,189	21.0 (3.0)	21.0 (2.8)	20.7 (2.7)	21.0 (2.8)	21.1 (3.0)
Socioeconomic Status
Poor	9201	39.4	13.1	34.9	25.4	8.8
Wealthy	8909	40.0	13.8	30.6	24.7	9.1
Region
Central Latin America/Caribbean	2742	42.3	16.1	32.1	26.7	10.2
Sub-Saharan Africa	4866	39.3	16.2	26.1	28.9	11.0
South/Southeast Asia	9725	39.1	11.9	36.3	23.6	6.8
Central Asia and other regions	3310	36.6	14.6	31.4	20.3	10.8
Country Income
Low- or lower middle-income 3	9725	37.7	13.5	31.0	24.8	9.3
Upper middle- or high-income 4	8486	41.5	13.4	34.3	25.3	8.7
Health Risk Behaviours
Tobacco use
No	15,848	39.7	12.8	33.9	24.7	8.1
Yes	2140	36.5	17.5	27.9	25.1	14.6
Binge alcohol use
No	14,140	40.1	12.6	32.5	24.5	8.6
Yes	3758	38.4	16.2	33.5	26.9	10.2
Physical inactivity
No	10,574	41.0	12.0	33.1	25.4	8.8
Yes	7348	40.0	13.0	35.7	23.5	8.3
Sedentary behaviour
No	12,378	40.7	13.2	32.9	26.8	8.6
Yes	5509	43.1	12.2	33.9	25.2	9.0
Depressive symptoms
No	15,834	39.0	13.2	33.7	24.1	7.1
Yes	2366	44.4	15.0	26.6	31.3	21.6

¹ Reference category for sleep duration is normal sleep (7–8 h); ² Reference category for sleep quality-problem is “None”; ³ Low- or lower middle-income country: Bangladesh, India, Ivory Coast, Kenya, Kyrgyzstan, Laos, Madagascar, Myanmar, Nigeria, Pakistan, Philippines, Tunisia and Vietnam; ⁴ Upper middle- or high-income country: Barbados, Colombia, Grenada, Jamaica, Malaysia, Mauritius, Namibia, Russia, Singapore, South Africa, Thailand, Turkey, and Venezuela [27]; M: Mean, SD: Deviation