Table A2.

Distributions of characteristics in original and imputed samples

	Original sample		Imputed sample
Characteristic	N or range	%^a or mean (SE^b)	% or mean (SE^b)
Total	2546	---	63,650
Female	1248	51	51
Age in years 1997	3.0–13.9	8.5 (0.059)	8.5 (0.059)
Missing	0	0	---
Age in years 2002	7.8–19.3	14.0 (0.068)	14.0 (0.068)
Missing	679	679	---
Age in years 2007	12.8–24.0	19.0 (0.068)	18.9 (0.059)
Missing	671	671	---
Race/Hispanicity
non-Hispanic white	1160	46	46
non-Hispanic black	1063	42	42
Hispanic	193	8	8
Other race	127	5	5
Missing	3	<1	---
Number of parent figures live with 1997
0	24	1	1
1	756	30	30
2	1762	69	69
Missing	4	<1	---
Number of parent figures live with 1997
0	3	<1	7
1	621	30	31
2	1438	70	62
Missing	484	19	---
Marital status of head of household 1997
Married	1606	63	63
Never married	406	16	16
Divorced/Separated/Widowed	533	21	21
Missing	1	<1	---
HOME scale 1997	8.8–24.0	18.9 (0.058)	18.7 (0.058)
Family income/poverty ratio 1996	0–36.9	2.9 (0.068)	2.9 (0.068)
Missing	0	0	---
Family income/poverty ratio 2002	0–111.6	3.7 (0.13)	3.4 (0.13)
Missing	186	7	---
Maximum of caregivers' completed years education 1997	3–17	13.2 (0.062)	13.2 (0.061)
<9	84	3	3
9–11	234	9	9
12	897	36	35
13–15	694	28	28
≥16	613	24	24
Missing	24	1	---
Caregiver achievement score	4–43	30.6 (0.16)	30.4 (0.14)
Missing	631	25	---
Neighborhood as place to raise children 1997
Excellent	427	27	27
Very good	481	30	30
Good	408	26	27
Fair/Poor	263	17	17
Missing	967	38	---
Neighborhood as place to raise children 2002
Excellent	621	30	31
Very good	633	31	29
Good	450	22	22
Fair/Poor	345	17	17
Missing	497	20	---
Urbanicity 1997
Central county, metropolitan area ≥1M	754	30	30
County, metropolitan area ≥250K	1044	41	41
Area <250K	748	29	29
Region 1997
Northeast	362	14	14
North Central	624	25	25
South	1152	45	45
West	407	16	16
Missing	1	<1	---
Primary caregiver-rated health compared to other babies at birth
Same	1633	65	65
Better	662	26	26
Worse	225	9	9
Missing	26	1	---
Low birth weight (<2500 g)	219	9	9
Missing	62	2	---
Spent time in NICU after birth	313	12	12
Missing	38	1	---
Number overnight hospital stays birth–1997
0	1912	75	75
1–2	519	20	20
≥3	107	4	4
Missing	8	<1	---
Number overnight hospital stays 1997–2002
0	1859	90	89
1–2	171	8	9
≥3	31	2	2
Missing	485	19	---
Routine physician check-up 1996–1997	1952	78	78
Missing	40	2	---
Routine physician check-up in 2001–2002	1713	84	83
Missing	507	20	---
Primary caregiver-rated health 1997
Excellent	1237	49	49
Very good	814	32	32
Good	410	16	16
Fair	65	3	3
Poor	5	<1	<1
Missing	15	<1	---
Primary caregiver-rated health 2002
Excellent	1090	53	47
Very good	653	32	32
Good	257	12	13
Fair	56	3	3
Poor	6	<1	5
Missing	484	19	---
Self-rated health 2007
Excellent	464	25	25
Very good	725	39	32
Good	518	28	28
Fair	152	8	10
Poor	14	1	5
Missing	673	26	---
BMI percentile 1997	0–100	59 (0.78)	59 (0.78)
<5 (underweight)	271	12	13
5–84.9 (normal)	1238	54	52
85–94.5 (overweight)	325	14	14
≥95 (obese)	459	20	21
Missing	253	10	---
BMI percentile 2002	0–100	66 (0.75)	66 (0.79)
< 5 (underweight)	49	3	5
5–84.9 (normal)	1102	60	55
85–94.5 (overweight)	288	16	17
≥95 (obese)	399	22	23
Missing	708	28	---
BMI status 2007 (age < 21/age 21+)
< 5^th percentile/<18.5 (underweight)	60	3	5
5–84.9^th percentile/18.5–24.9 (normal)	1035	56	53
85–94.5^th percentile/25–29.9 (overweight)	394	21	22
≥ 95^th percentile/≥ 30 (obese)	347	19	20
Missing	710	28	---
Children's Depression Inventory 2002 (age 12+)	0–18	3.0 (0.092)	3.5 (1.27)
Missing	566	22	---
Too young to be asked question^c	725	28	21
K-6 Non-Specific Psychological Distress Scale 2007 (age 18+)	0–23	5.2 (0.11)	5.2 (0.17)
Missing	522	21	---
Too young to be asked questionc	911	36	35
Behavior Problems Index 1997	0–27	8.0 (0.13)	8.0 (0.13)
Missing	102	4	---
Behavior Problems Index 2002	0–30	8.7 (0.16)	8.7 (0.15)
Missing	509	20	---
Ever repeated a grade 1997	159	6	7
Missing	67	3	---
Changed school during current school year 1997	129	5	5
Missing	49	2	---
Changed school during current school year 2002	122	6	6
Not in school	29	1	8
Missing	513	20	---
Type of school 1997
Public	1867	90	81
Private	188	9	8
Home	17	1	11
Missing	474	19	---
Type of school 2002
Public	1784	91	78
Private	126	6	5
Home	28	1	9
Not in school	29	1	8
Missing	579	23	---
Academic achievement 1997	40.5–163.0	104.3 (0.42)	104.4 (0.40)
Missing	745	29	---
Academic achievement 2002	42.0–169.5	102.2 (0.42)	101.9 (0.39)
Missing	691	27	---
Mean academic achievement 1997–2002	42.0–169.5	103.1 (0.37)	103.1 (0.36)
Missing	316	12	---
Change in academic achievement 1997–2002	−48.0–72.5	−2.6 (0.35)	−2.5 (0.32)
Missing	1120	44	---

To facilitate comparison with the imputed sample, the denominators for percents for nonmissing categories include only observations with nonmissing information. To facilitate interpretation,denominators also exclude participants ineligible to be asked the question because of age.

Standard error of the mean.

Estimated from age in 1997 for participants missing from this wave