Table 2.

Linear regression analysis of the impact of oral health knowledge and demographic variables on oral hygiene change (Δ OHI_S)

	Unstandardized Coefficients		Coefficients Standardized			95% Confidence Interval for B
	B	Std. Error	Beta	t	P-value	Lower	Upper
Gender
Boy	Ref
Girl	−0.03	0.03	−0.04	−0.95	0.34	−0.08	0.03
Group
Control	Ref
Intervention	−0.28	0.03	−0.46	−10.32	0.00	−0.33	−0.23
Father’s Education
Illiterate/Elementary school1/Middle school2	Ref
High school or Diploma3	0.02	0.02	5.27	1.41	0.16	−0.01	0.06
Associate4/Bachelor/Master’s of science/Doctorate	−0.02	0.02	−5.24	−1.4	0.16	−0.06	0.01
Mother’s Education
Illiterate/Elementary school1/Middle school2	Ref
High school or Diploma3	−0.01	0.04	−0.02	−0.3	0.76	−0.1	0.07
Associate4/Bachelor/Master’s of science/Doctorate	0.07	0.05	0.11	1.41	0.16	−0.03	0.16
Child birth order
First or Second	Ref
Third & more	0.00	0.00	−0.01	−0.32	0.75	0.00	0.00
Number of children in the household
1 and 2	Ref
3 and more	−0.03	0.04	−0.03	−0.7	0.46	−0.12	0.05
Socio-economic status5
Less than 16.5	Ref
Between 16.5–33	−0.04	0.03	−0.07	−1.42	0.16	−0.11	0.02
More than 33	−0.12	0.05	−0.14	−2.62	0.01	−0.22	−0.03
Supervised tooth brushing by parens
Not supervised	Ref
Supervised	0.00	0.02	0.00	0.54	0.96	−0.03	0.03
ΔKnowledge (9Qs)	−0.00	0.01	−0.02	−0.35	0.73	−0.02	0.01

Hygiene change (ΔOHI-S); Dependent Variable: ΔOHI_S;

¹5 years;

²6–8 years;

³9–12 years;

⁴2 years of academic education;

⁵Housing area (m² per person)