Table 1.

Characteristics of ED visits with valid New York University ED classification from the 1997-2009 National Hospital Ambulatory Medical Care Survey (N = 241,167 records)

Characteristics	Observed (N)	Weighted % (95% CI)
Health insurance type
Private	83,586	36.2 (35.3–37.2)
Medicare	42,155	18.2 (17.6–18.7)
Medicaid	57,739	23.1 (22.3–23.9)
Self-pay/uninsured	34,345	15.2 (14.6–15.8)
Other	18,007	7.3 (6.7–8.0)
Arrival time
Business hours (M-F, 8:00–15:59)	72,330	29.7 (29.4–30.1)
Weekend evenings (M-F, 16:00–23:59)	69,389	29.1 (28.9–29.4)
Nights (M-Su, 0:00–7:59)	38,663	16.2 (15.9–16.5)
Weekends (Sa-Su, 8:00–23:59)	58,806	24.9 (24.6–25.2)
Age, yr
0–9	42,802	17.8 (17.0–18.6)
10–19	22,556	9.5 (9.3–9.7)
20–29	38,330	16.0 (15.7–16.4)
30–39	33,554	13.9 (13.6–14.1)
40–49	31,847	13.0 (12.8–13.3)
50–59	23,591	9.7 (9.5–9.9)
60–69	16,850	7.0 (6.8–7.2)
≥ 70	31,637	13.2 (12.7–13.6)
Sex
Female	138,175	57.6 (57.3–57.9)
Male	102,992	42.4 (42.1–42.8)
Race/ethnicity
Non-Hispanic white	142,138	62.0 (60.2–63.8)
Non-Hispanic black	56,628	22.7 (21.0–24.5)
Hispanic	32,555	12.2 (10.8–13.7)
Other	9,846	3.1 (2.7–3.6)
Region
Northeast	56,875	18.4 (16.4–20.5)
Midwest	52,986	23.8 (20.9–27.0)
South	85,561	40.1 (36.4–43.9)
West	45,763	17.7 (15.2–20.5)
Metropolitan statistical area
Urban	206,968	81.4 (75.2–86.4)
Nonurban	34,199	18.6 (13.6–24.8)