Table 4.

The multivariate logistic regression with number of teeth as the dependent variable and, linear trend over time (study year), age, marital status and social group as the independent variables

Independent variables	P-value	Odds ratio	95% confidence interval
Dependent variable: Number of teeth 1+ vs 0 teeth (Model I)
Linear trend over time	<0.001	0.20	0.13-0.31
38 years old (reference)
50 years old	<0.001	4.79	2.73-8.43
Living together (reference)
Single living	0.028	1.74	1.06-2.84
High social group (reference)
Medium social group	0.051	7.42	0.99-55.45
Low social group	0.002	24.72	3.38-180.96
Dependent variable: Number of teeth 11+ vs 0–10 teeth (Model II)
Linear trend over time	<0.001	0.21	0.15-0.28
38 years old (reference)
50 years old	<0.001	5.09	3.45-7.50
Living together (reference)
Single living	0.004	1.74	1.20-2.52
High social group (reference)
Medium social group	0.001	4.86	1.90-12.43
Low social group	<0.001	11.57	4.58-29.35
Dependent variable: Number of teeth 21+ vs 0–20 teeth (Model III)
Linear trend over time	<0.001	0.25	0.21-0.30
38 years old (reference)
50 years old	<0.001	4.94	3.72-6.55
Living together (reference)
Single living	0.001	1.63	1.21-2.20
High social group (reference)
Medium social group	<0.001	2.92	1.78-4.80
Low social group	<0.001	5.61	3.41-9.23
Dependent variable: Number of teeth 25+ vs 0–24 teeth (Model IV)
Linear trend over time	<0.001	0.30	0.26-0.34
38 years old (reference)
50 years old	<0.001	4.39	3.42-5.63
Living together (reference)
Single living	0.005	1.48	1.13-1.93
High social group (reference)
Medium social group	<0.001	2.13	1.47-3.10
Low social group	<0.001	4.13	2.81-6.08