Table 4. Relationship between demographic factors and sleep quality after surgery (n=374)

Factors	Quality of sleep			p (CI: 95%)
		Good	Poor
Age	≤ 50 years	38	130	p = 0.005 OR = 2.02 (1.23- 3.32).
	> 50 years	44	162
Ethnic group	Kinh people	53	204	p = 0.81 OR = 1.26 (0.75- 2.12)
	Ethnic minority	29	88
Gender	Female	37	108	p = 0.18 OR = 1.26 (0.85- 2.29)
	Male	45	184
Educational level	High school or higher education	23	47	p < 0.05 OR = 2.03 (1.14 – 3.6)
	Other (Primary/ Secondary education)	59	245