Table 2.

Relations between orthodontic treatment and social characteristics (weighted multivariate logistic regression)

	cOR1	95%CI	aOR2	95%CI	p3	aOR4	95%CI	p5
Sex
Boys	ref		ref			ref
Girls	1.21	[1.03–1.41]	1.20	[1.01–1.42]	0.036	1.20	[1.01–1.42]	0.035
Age group
8–11 years	0.34	[0.28–0.42]	0.33	[0.27–0.41]		0.33	[0.27–0.41]
12–15 years	ref		ref			ref
16–18 years	0.32	[0.26–0.40]	0.33	[0.26–0.41]	<0.001	0.33	[0.27–0.42]	<0.001
Family structure
Two-parent	ref		ref			ref
One-parent	0.89	[0.72–1.11]	1.21	[0.92–1.60]	0.177	1.18	[0.90–1.56]	0.235
Number of children
1	0.70	[0.57–0.85]	0.78	[0.63–0.96]		0.79	[0.64–0.98]
2	ref		ref			ref
3	0.87	[0.71–1.07]	0.93	[0.75–1.17]		0.94	[0.76–1.72]
4 and more	0.41	[0.28–0.61]	0.55	[0.36–0.86]	0.009	0.56	[0.36–0.86]	0.014
Place of birth of mother (or stepmother)
France	ref		ref			ref
Other Europe	1.04	[0.71–1.52]	1.03	[0.70–1.52]		1.05	[0.71–1.56]
Africa	0.46	[0.34–0.62]	0.61	[0.44–0.85]		0.63	[0.45–0.88]
Other World	1.09	[0.66–1.78]	1.24	[0.71–2.16]	0.024	1.25	[0.71–2.19]	0.032
Maternal educational attainment
No or primary education	0.36	[0.28–0.46]				0.59	[0.43–0.81]
Vocational qualification	0.61	[0.49–0.75]				0.77	[0.60–0.98]
General secondary education dilpoma	0.72	[0.58–0.88]				0.85	[0.68–1.08]
Post secondary certification	ref					ref		0.009
Family social status
Professionals, managers	ref		ref
Intermediate professionals	0.75	[0.61–0.92]	0.89	[0.70–1.13]
Office workers, self-employed, farmers, shopkeepers	0.55	[0.44–0.69]	0.73	[0.56–0.96]
Service and sales workers	0.39	[0.28–0.54]	0.50	[0.34–0.76]
Manual workers	0.34	[0.25–0.46]	0.56	[0.39–0.81]	0.002
Income (euros)
< 18 000	0.42	[0.33–0.53]	0.62	[0.45–0.85]		0.56	[0.41–0.76]
18 000 – 27 000	0.48	[0.39–0.59]	0.64	[0.49–0.83]		0.60	[0.47–0.77]
27 000 – 39 000	0.63	[0.51–0.78]	0.76	[0.60–0.96]	0.003	0.74	[0.59–0.94]
> 39 000	ref		ref			ref		<0.001
Supplementary insurance
Private	ref		ref			ref
Government	0.59	[0.40–0.87]	0.89	[0.53–1.48]		0.97	[0.61–1.53]
None	0.35	[0.24–0.52]	0.53	[0.34–0.81]	0.013	0.53	[0.35–0.81]	0.013
Residence area
Urban	ref		ref			ref
Rural	0.68	[0.54–0.87]	0.70	[0.54–0.91]	0.008	0.68	[0.53–0.89]	0.004
Density of orthodontists6
< 21.5	0.60	[0.46–0.79]	0.76	[0.57–1.01]		0.83	[0.61–1.14]
21.5 – 26.8	0.75	[0.59–0.96]	0.79	[0.61–1.02]		0.79	[0.58–1.07]
26.8 – 33.7	0.75	[0.60–0.92]	0.82	[0.65–1.03]		0.84	[0.66–1.05]
33.7 – 53.3	0.75	[0.58–0.97]	0.80	[0.61–1.06]		0.80	[0.63–1.01]
> 53.3	ref		ref		0.211	ref		0.302

¹crude odds-ratio and 95% confidence interval

²adjusted odds-ratio for all variables in the table except maternal educational attainment and 95% confidence interval

³adjusted Wald χ² p-value for all variables in the table except maternal educational attainment

⁴adjusted odds-ratio for all variables in the table except family social status and 95% confidence interval

⁵adjusted Wald χ² p-value for all variables in the table except family social status

⁶in the department for 100 000 inhabitants, aged 10 to 15 years