Table II.

Associations of HbA_1c with clinical and demographic characteristics (adjusted): SEARCH for Diabetes in Youth, prevalent 2001 and incident 2002–2005 study participants

Characteristic	T1D (n = 3606)			T2D (n = 421)
	Estimate	95% CI	P *	Estimate	95% CI	P *
Age at examination, years			<.0001			.1470
0–5	Ref	—	—	—	—	—
6–12	−0.33	−0.49 to −0.16	<.0001	0.66	−1.60 to 0.28	.1679
13–18	−0.15	−0.32 to 0.03	.0956	−0.75	−1.50 to 0.00	.0515
19+	−0.56	−0.84 to −0.28	<.0001	Ref	—	—
Diabetes duration, months			<.0001			.0058
< 12	Ref	—	—	Ref	—	—
12–23	0.67	0.54 to 0.80	<.0001	0.41	−0.14 to 0.96	.1417
24–47	0.89	0.74 to 1.03	<.0001	0.72	0.08 to 1.36	.0286
48+	1.18	1.05 to 1.30	<.0001	1.38	0.60 to 2.17	.0006
Weight status†			.0018			.2378
Underweight or normal weight (< 85th percentile)	0.19	0.05 to 0.34	.0096	0.57	−0.15 to 1.29	.1231
Overweight (85th to 94th percentile)	0.02	−0.15 to 0.19	.8255	0.33	−0.36 to 1.02	.3447
Obese (> 95th percentile)	Ref	—	—	Ref	—	—
Family structure			.0003			.1866
Two-parent household	Ref	—	—	Ref	—	—
Single-parent household	0.19	0.08 to 0.30	.0011	−0.42	−0.91 to 0.07	.0896
Other household structure	0.39	0.14 to 0.65	.0024	0.01	−0.80 to 0.83	.9746
Diabetes care provider			.0049			.1218
Pediatric endocrinologist or diabetologist	Ref	—	—	Ref	—	—
Adult endocrinologist	0.41	0.10 to 0.72	.0090	0.34	−0.79 to 1.47	.5517
General pediatrician or family physician or general internist	0.21	−0.05 to 0.47	.1069	0.49	−0.32 to 1.30	.2346
Nurse practitioner or physician assistant	−0.06	−0.19 to 0.07	.3831	0.78	−0.01 to 1.56	.0530
Other/don’t know	−0.07	−0.42 to 0.29	.7130	−0.12	−1.19 to 0.95	.8221
None, no medical care	1.48	0.41 to 2.54	.0068	1.96	0.18 to 3.75	.0310
Race/ethnicity			<.0001			.1322
Non-Hispanic white	Ref	—	—	Ref	—	—
African American	0.69	0.52 to 0.87	<.0001	0.52	−0.09 to 1.14	.0959
Hispanic	0.25	0.09 to 0.40	.0025	0.47	−0.19 to 1.13	.1652
Asian/Pacific Islander	0.41	0.14 to 0.67	.0027	0.90	0.03 to 1.77	.0418
American Indian	1.02	0.34 to 1.71	.0034	1.16	0.10 to 2.21	.0327
Sex			.0277			.7680
Female	0.10	0.01 to 0.20	.0277	0.07	−0.38 to 0.52	.7680
Male	Ref	—	—	Ref	—	—
Household income			.0597			.4847
<$25 K	Ref	—	—	Ref	—	—
$25–49 K	−0.13	−0.31 to 0.04	.1323	−0.04	−0.61 to 0.52	.8813
$50–74 K	−0.22	−0.42 to −0.02	.0328	0.17	−0.61 to 0.96	.6622
$75 + K	−0.27	−0.47 to −0.07	.0081	−0.53	−1.42 to 0.36	.2434
Parental education			<.0001			.0447
Less than high school	0.40	0.12 to 0.68	.0052	−0.07	−0.90 to 0.77	.8694
High school graduate or GED	0.35	0.19 to 0.50	<.0001	−0.75	−1.43 to −0.07	.0300
Some college (but less than bachelor’s degree)	0.26	0.15 to 0.38	<.0001	−0.64	−1.30 to 0.01	.0554
Bachelor’s degree or more	Ref	—	—	Ref	—	—
Insurance			.2499			.8844
None	0.38	−0.04 to 0.79	.0763	0.20	−1.12 to 1.53	.7617
Private	Ref	—	—	Ref	—	—
Medicaid/Medicare	0.03	−0.13 to 0.20	.6946	−0.18	−0.75 to 0.39	.5347
Other‡	−0.17	−0.54 to 0.20	.3720	−0.25	−1.42 to 0.92	.6760

^*Each characteristic was adjusted for all other variables shown in the table, with HbA_1c treated as a continuous outcome (n = 3606 for the type 1 adjusted model and n = 421 for the type 2 adjusted model).

^†Weight status defined based on CDC guidelines using age- and sex-specific BMI percentiles (Ref).

^‡Includes Indian Health Service, military, school-based, and other (when these are not in combination with either private insurance or Medicaid/Medicare).