Table 2.

Characteristics of infants hospitalized for RSV in the National Inpatient Sample and Kids Inpatient Database

	NIS		KID
	Weighted n a	%	Weighted n b	%
Total	361,685	100.0	136,344	100.0
Sex
Male	206,214	57.0	77,114	56.6
Female	155,428	43.0	59,215	43.4
Missing	43	0.0	14	0.0
Race/ethnicity
White, non-Hispanic	146,803	40.6	52,572	38.6
Black, non-Hispanic	39,806	11.0	14,886	10.9
Native American	3773	1.0	1167	0.9
Hispanic	60,732	16.8	23,506	17.2
Asian	6336	1.8	2178	1.6
Other	16,776	4.6	6053	4.4
Unknown/missing	87,457	24.2	35,981	26.4
Payer type
Private	126,568	35.0	46,661	34.2
Public	211,939	58.6	81,333	59.7
Self-pay	11,426	3.2	4175	3.1
Other	10,779	3.0	3819	2.8
No charge/unknown	973	0.3	356	0.3
Hospital/site region
Northeast	63,270	17.5	22,883	16.8
Midwest	84,040	23.2	35,774	26.2
South	130,880	36.2	43,966	32.2
West	83,494	23.1	33,721	24.7
Household incomec
1st quartile	119,605	33.1	46,983	34.5
2nd quartile	95,435	26.4	36,373	26.7
3rd quartile	76,469	21.1	28,750	21.1
4th quartile	61,275	16.9	20,617	15.1
Missing	8902	2.5	3621	2.7

KID Kid Inpatient Database, NIS National Inpatient Sample, RSV respiratory syncytial virus

^aAfter excluding the states (Florida, Massachusetts, Maine, New Hampshire, South Carolina, and Texas) with missing “age in days” variable, discharge weights were rescaled to match the national estimate of discharges

^bAfter excluding the states (Connecticut, Florida, Massachusetts, Maine, New Hampshire, South Carolina, and Texas) with missing “age in days” variable, discharge weights were rescaled to match the national estimate of discharges

^cQuartile ranges change by year for NIS and KID (http://www.hcup-us.ahrq.gov/db/vars/zipinc_qrtl/nisnote.jsp). For Anderson et al. [17]: quartile 1 = $1–39,999; quartile 2 = $40,000–50,999; quartile 3 = $51,000–65,999; quartile 4 = $66,000+