Table 2. Baseline characteristics 1996 to 1999, comparing those included and those excluded because Medicare was not the sole, primary payer

Dialysis Inception 1996 to 1999	Included (%; n = 196,356)	Excluded (%; n = 96,076)	P^a	Odds Ratio for Exclusion^b	95% CI^b	P^b
^a Using the χ² test.
^b Using a multiple logistic regression model including the variables shown in the first column. The reference categories were peritoneal dialysis; age 20 to 44 yr; male gender; other race; non-Hispanic ethnicity; 1996 as year of dialysis inception; absence of congestive heart failure, atherosclerotic heart disease, cardiac arrest or dysrhythmia, stroke or transient ischemic attack, peripheral vascular disease, chronic obstructive pulmonary disease, current tobacco use, cancer, alcohol or drug dependence, inability to ambulate or transfer; hemoglobin 11 to 12 g/dl; serum albumin 3.1 to 3.4 g/dl; estimated GFR 5.1 to 10 ml/min per 1.73 m²; and body mass index 18.5 to 24.9 kg/m².
^c Age data were missing in 0.007% of patients and 0.008% of excluded individuals.
Mode of dialysis			<0.0001
hemodialysis	89.6	86.0		0.92	0.90 to 0.94	<0.0001
peritoneal dialysis	10.4	14.0		1	—	—
Age (yr)^c			<0.0001
0 to 19	0.8	2.0		1.47	1.37 to 1.57	<0.0001
20 to 44	13.2	21.6		1	—	—
45 to 64	30.7	47.4		0.98	0.96 to 1.00	0.07
65 to 74	30.6	17.7		0.36	0.35 to 0.37	<0.0001
≥75	24.7	11.4		0.28	0.27 to 0.29	<0.0001
Gender			<0.0001
male	52.9	54.9
female	47.1	45.1		0.96	0.95 to 0.98	<0.0001
Race			<0.0001	1	—	—
white	61.4	60.6		0.93	0.89 to 0.97	0.001
black	32.1	30.4		0.70	0.67 to 0.74	<0.0001
Asian	3.1	4.6		1.26	1.18 to 1.33	<0.0001
other	3.4	4.4			—	—
Hispanic ethnicity			<0.0001
yes	11.5	12.8		0.89	0.87 to 0.91	<0.0001
no	88.5	87.2		1	—	—
Year of dialysis inception			<0.0001
1996	23.5	21.3		1	—	—
1997	24.2	24.2		1.13	1.10 to 1.16	<0.0001
1998	25.5	26.2		1.18	1.15 to 1.21	<0.0001
1999	26.8	28.2		1.22	1.19 to 1.24	<0.0001
Congestive heart failure	34.1	26.1	<0.0001	0.91		<0.0001
Atherosclerotic heart disease	27.3	20.4	<0.0001	0.95	0.93 to 0.97	<0.0001
Cardiac arrest or dysrhythmia	6.6	4.5	<0.0001	0.97	0.94 to 1.01	0.1
Stroke or transient ischemic attack	9.5	6.7	<0.0001	0.87	0.84 to 0.90	<0.0001
Peripheral vascular disease	15.3	11.3	<0.0001	0.91	0.88 to 0.93	<0.0001
Diabetes	46.7	44.2	<0.0001	0.92	0.91 to 0.94	<0.0001
Chronic obstructive pulmonary disease	7.4	4.9	<0.0001	0.90	0.87 to 0.93	<0.0001
Current tobacco use	5.6	5.2	<0.0001	0.78	0.75 to 0.81	<0.0001
Cancer	5.0	4.0	<0.0001	1.00	0.96 to 1.04	1.00
Alcohol or drug dependence	2.3	2.5	<0.0001	0.91	0.87 to 0.96	0.0009
Inability to ambulate or transfer	4.3	3.1	<0.0001	0.96	0.91 to 1.00	0.05
Hemoglobin (g/dl)			<0.0001
missing	6.3	5.0		0.77	0.74 to 0.81	<0.0001
<11	76.3	76.2		0.92	0.90 to 0.94	<0.0001
11 to 12	10.9	11.5		1	—	—
>12	6.6	7.4		1.04	1.00 to 1.08	0.05
Serum albumin (g/dl)			<0.0001
missing	22.6	21.6		1.01	0.99 to 1.04	0.4
≤3.0	30.8	30.0		0.98	0.96 to 1.01	0.1
3.1 to 3.4	19.0	18.0		1	—	—
≥3.5	27.7	30.4		1.08	1.05 to 1.11	<0.0001
Estimated GFR (ml/min per 1.73 m²)			<0.0001
missing	2.5	1.7		0.67	0.63 to 0.71	<0.0001
≤5.0	16.8	20.1		1.01	0.99 to 1.03	0.6
5.1 to 10.0	56.9	58.0		1	—	—
>10.0	23.8	20.2		0.94	0.92 to 0.96	<0.0001
Body mass index (kg/m²)			<0.0001
missing	2.9	2.2		0.78	0.73 to 0.82	<0.0001
<18.5	6.6	6.0		0.95	0.92 to 0.98	0.004
18.5 to 24.9	42.1	40.1		1	—	—
25 to 29.9	26.7	27.3		1.01	0.99 to 1.03	0.2
≥30	21.7	24.4		0.99	0.97 to 1.01	0.4