TABLE 1.

ORs for Association Between Demographic Variables and Probability of FBD, by Time Periods

	1991–1998 n = 363 178	1999–2006 n = 339 799	2007–2015 n = 362 045	Interactions
				1991–1998 vs 1999–2006	1999–2006 vs 2007–15	1991–1998 vs 2007–2015
Sex
Boy	1	1	1
Girl	0.58 (0.57–0.60)	0.65 (0.64–0.67)	0.71 (0.70–0.73)	***	***	***
Race
White	1	1	1
African American	0.42 (0.40–0.44)	0.42 (0.40–0.44)	0.53 (0.51–0.56)	N/S	***	***
Hispanic	1.00 (0.97–1.04)	0.97 (0.93–1.00)	0.96 (0.93–1.00)	N/S	N/S	N/S
Other	0.75 (0.72–0.77)	0.75 (0.72–0.78)	0.78 (0.75–0.81)	N/S	N/S	N/S
Parent education
High school or less	1	1	1
College or more	0.83 (0.82–0.85)	0.81 (0.79–0.83)	0.79 (0.77–0.81)	N/S	N/S	***
Age, y
13–14	1	1	1
14–15	1.40 (1.33–1.47)	1.35 (1.28–1.43)	1.44 (1.33–1.55)	N/S	N/S	N/S
15–16	2.41 (2.30–2.53)	2.84 (2.69–2.99)	3.29 (3.07–3.52)	***	***	***
16–17	2.82 (2.69–2.95)	3.28 (3.12–3.45)	3.74 (3.50–4.00)	**	**	***
17–18	4.08 (3.90–4.27)	4.49 (4.26–4.72)	5.64 (5.28–6.02)	***	***	***
18–19	4.59 (4.39–4.81)	5.18 (4.92–5.44)	6.40 (6.00–6.83)	***	***	***

95% confidence intervals are in parentheses. N/S, not significant.

^**P < .01.

^***P < .001.