TABLE 2.

Risk Factors for Sleep-Related Death by Age Category

Characteristic	Totala		Age Categorya				P
			0–3 Months		4 Months to 364 Days
	n	%	n	%	n	%
Bed-sharing							<.001
Yes	5681	69.2	4191	73.8	1489	58.9
No	2333	28.4	1375	24.2	958	37.9
Unknown	193	2.4	111	1.9	83	3.3
Number of objects in the sleep environment							<.001
0	5308	64.7	3775	66.5	1533	60.6
1	2014	24.5	1295	22.8	719	28.4
2	672	8.2	461	8.1	211	8.3
3	182	2.2	127	2.2	55	2.2
4	25	0.3	15	0.3	10	0.4
5	5	0.1	3	0.1	2	0.1
6	1	0.0	1	0.0	0	0.0
One or more dangerous objectsb	2879	33.3	1893	33.4	986	39.0	<.001
Position placed to sleep							<.001
On back	3258	39.7	2160	38.0	1098	43.4
On side	1041	12.7	820	14.4	221	8.7
On stomach	1806	22.0	1299	22.9	507	20.0
Unknown	2102	25.6	1398	24.6	704	27.8
Position infant found							<.001
On back	2204	26.9	1567	27.6	637	25.2
On side	981	11.9	710	12.5	271	10.7
On stomach	3144	38.3	2075	36.6	1068	42.2
Unknown	1878	22.9	1325	23.3	554	21.9
Change in position from position placed to position found							<.001
Back/side to back/side	2676	32.6	1934	34.1	742	29.3
Back/side to stomach	1251	15.2	786	13.8	465	18.4
Stomach to stomach	1501	18.3	1083	19.1	418	16.5
Stomach to back/side	157	1.9	101	1.8	56	2.2
Either placed or found position unknown	2622	32.0	1774	31.3	848	33.5
Sleep place at time of death							<.001
Crib, bassinet, or playpen	2259	27.5	1398	24.6	860	34.0
Car seat, stroller, or infant chair	245	3.0	174	3.1	72	2.8
Adult bed or person	4037	49.2	2929	51.6	1108	43.8
Other	1393	17.0	984	17.3	409	16.2
Unknown	273	3.3	192	3.4	81	3.2

^aFrequencies are nonintegers due to averaging over 5 independent imputations during the multiple imputation process; frequencies shown are rounded to the nearest integer.

^b“Dangerous objects” includes pillows, blankets, bumper pads, stuffed toys, clothing, cords, and bags.