Table 2

Odds ratios for appendiceal rupture among children in the United States.
		Unadjusted race/ethnicity odds	Race/ethnicity odds adjusted for biologic factors	With additional adjustments for social and system factors	With additional adjustments for hospital factors

Race/ethnicity	white	ref	ref	ref	ref
	black	1.40 (1.27–1.55)	1.38 (1.25–1.53)	1.27 (1.14–1.42)	1.23 (1.10–1.37)
	Hispanic	1.36 (1.28–1.44)	1.24 (1.17–1.31)	1.14 (1.07–1.22)	1.07 (1.00–1.15)
	Asian	1.37 (1.16–1.61)	1.32 (1.13–1.52)	1.29 (1.10–1.53)	1.24 (1.05–1.46)

Gender	male		1.00 (0.95–1.06)	0.99 (0.94–1.05)	0.99 (0.94–1.05)
	female		ref	ref	ref

Age group	4–8		2.05 (1.90–2.21)	2.02 (1.87–2.18)	1.90 (1.76–2.06)
	9–11		1.36 (1.25–1.47)	1.36 (1.25–1.47)	1.30 (1.20–1.41)
	12–14		1.32 (1.23–1.42)	1.31 (1.22–1.42)	1.28 (1.18–1.38)
	15–18		ref	ref	ref

ZIP code median annual household income	$0–$24,999			1.15 (1.05–1.27)	1.13 (1.02–1.24)
	$25,000–$34,999			1.06 (0.99–1.14)	1.11 (1.03–1.20)
	$35,000–$44,999			1.00 (0.93–1.08)	1.04 (0.96–1.12)
	≥ $45,000			ref	ref

Expected primary payer	private			ref	ref
	public			1.10 (0.99–1.23)	1.09 (0.98–1.21)
	other			0.87 (0.78–0.97)	0.87 (0.78–0.96)

Admission source	emergency department			ref	ref
	other healthcare referral			1.28 (1.19–1.38)	1.29 (1.20–1.39)
	other			1.03 (0.93–1.14)	1.05 (0.95–1.16)

Hospital type	teaching				1.06 (0.99–1.14)
	other				ref

Pediatric discharge volume	4–1,578				0.72 (0.65–0.80)
	1,579–3,471				0.73 (0.66–0.80)
	3,472–6,582				0.79 (0.73–0.86)
	6,583–22,785				ref

Sample size	unweighted	32,784	32,773	30,940	30,940
	weighted	62,555	62,533	57,791	57,791

Jablonski and Guagliardo Population Health Metrics 2005 3:4 doi:10.1186/1478-7954-3-4