Table 1.

Geocoding match rates at each level for 85,397 non-PO Box and PO Box addresses by selected characteristics, Southern Community Cohort Study, USA 2002–2009.

	Geocode level
	Street address		Street centroid		ZIP code centroid (non-PO Box address)		ZIP code centroid (PO Box address)		Did not geocode
Characteristic	N	%	N	%	N	%	N	%	N	%
Total population	79,811	93.46	1,148	1.34	1,981a	2.32	2,424	2.84	33	0.04
State
Alabama	17,048	94.88	275	1.53	322	1.79	315	1.75	8	0.04
Arkansas	4,556	87.90	160	3.09	209	4.03	258	4.98	0	0.00
Florida	5,395	96.56	26	0.47	29	0.52	134	2.40	3	0.05
Georgia	10,153	96.29	100	0.95	138	1.31	148	1.40	5	0.05
Kentucky	6,870	97.09	48	0.68	66	0.93	92	1.30	0	0.00
Louisiana	3,273	97.58	29	0.86	29	0.86	23	0.69	0	0.00
Mississippi	12,046	89.90	321	2.40	416	3.10	608	4.54	9	0.07
North Carolina	2,041	97.66	2	0.10	8	0.38	39	1.87	0	0.00
South Carolina	4,573	89.28	78	1.52	130	2.54	339	6.62	2	0.04
Tennessee	7,052	98.44	33	0.46	30	0.42	48	0.67	1	0.01
Virginia	3,873	93.17	28	0.67	184	4.43	70	1.68	2	0.05
West Virginia	2,931	78.12	48	1.28	420	11.19	350	9.33	3	0.08
Population density quartilesb
Q1	18,128	83.12	702	3.22	1,482	6.80	1,497	6.86	0	0.00
Q2	20,328	96.52	176	0.84	268	1.27	289	1.37	0	0.00
Q3	20,331	98.55	110	0.53	75	0.36	115	0.56	0	0.00
Q4	20,437	98.74	122	0.59	97	0.47	42	0.20	0	0.00
Enrollment source
CHC	68,769	94.02	1,062	1.45	1,644	2.25	1,636	2.24	30	0.04
General population	11,042	90.09	86	0.70	337	2.75	788	6.43	3	0.02
Sex
Male	32,380	93.47	501	1.45	813	2.35	926	2.67	21	0.06
Female	47,431	93.45	647	1.27	1,168	2.30	1,498	2.95	12	0.02
Race
African American	52,872	94.45	735	1.31	888	1.59	1,464	2.62	21	0.04
White	23,110	91.46	359	1.42	963	3.81	826	3.27	9	0.04
Other	3,829	92.27	54	1.30	130	3.13	134	3.23	3	0.07
Annual household income
<US$ 15,000	42,786	93.74	649	1.42	997	2.18	1,190	2.61	20	0.04
US$ 15,000–24,999	16,335	93.64	241	1.38	412	2.36	450	2.58	7	0.04
US$ 25,000–49,999	10,892	93.21	145	1.24	282	2.41	364	3.11	3	0.03
≥US$ 50,000	7,366	92.51	66	0.83	212	2.66	316	3.97	2	0.03
Education (years)
<9	6,012	90.50	131	1.97	238	3.58	256	3.85	6	0.09
9–11	16,217	93.55	271	1.56	403	2.32	437	2.52	7	0.04
12–15	45,665	93.90	615	1.26	1,079	2.22	1,261	2.59	14	0.03
≥16	10,187	93.53	94	0.86	202	1.85	404	3.71	5	0.05

Abbreviations: CHC = Community Health Center; PO = Post Office.

^aOf these, all were delivery-weighted. 7 were ZIP + 4 centroids, 595 (30.0%) were ZIP + 2 centroids, and 1,379 (69.6%) were 5-digit ZIP code centroids.

^bQ1: <44 persons/km², Q2: 44–236 persons/km², Q3: 237–920 persons/km², Q4: >920 persons/km².