Table 1. Characteristics of the 6-Month Cohort at Enrollment.
| IDA | Nonanemic | |||
|---|---|---|---|---|
| Surveillance (N = 36) |
Intervention (N = 33) |
Surveillance (N = 26) |
Intervention (N = 33) |
|
| Family characteristics | ||||
| Maternal age, y | 27.6 ± 1.5 | 27.1 ± 1.2 | 26.6 ± 1.0 | 27.3 ± 1.2 |
| Maternal education, ya | 7.9 ± 0.5 | 9.2 ± 0.6 | 9.5 ± 0.6 | 9.9 ± 0.4 |
| Maternal IQa,b | 79.5 ± 1.6 | 81.8 ± 2.0 | 86.4 ± 2.0 | 84.9 ± 2.0 |
| Maternal depressionc | 16.9 ± 2.1 | 14.1 ± 2.4 | 15.3 ± 2.4 | 9.9 ± 1.6 |
| Father present, n (%) | 26 (72.2) | 26 (78.8) | 22 (84.6) | 25 (75.8) |
| Household head education, y | 8.0 ± 0.5 | 9.0 ± 0.6 | 9.2 ± 0.6 | 8.7 ± 0.7 |
| No. of people in household | 5.0 ± 0.2 | 5.2 ± 0.4 | 5.2 ± 0.4 | 6.0 ± 0.6 |
| Social class indexd | 27.5 ± 1.2 | 29.9 ± 1.4 | 28.2 ± 1.6 | 27.4 ± 1.2 |
| Life stressa,e | 4.9 ± 0.4 | 4.9 ± 0.5 | 4.0 ± 0.4 | 3.6 ± 0.4 |
| Home environmentf | 28.1 ± 0.8 | 27.9 ± 1.1 | 29.7 ± 0.9 | 29.5 ± 0.9 |
| Child characteristics | ||||
| Male, n (%)g | 23 (63.9) | 28 (84.8) | 14 (53.8) | 17 (51.5) |
| Birth weight, kga | 3.38 ± 0.05 | 3.47 ± 0.06 | 3.57 ± 0.08 | 3.60 ± 0.07 |
| Gestational age, wk | 39.2 ± 0.2 | 39.1 ± 0.2 | 39.4 ± 0.2 | 39.5 ± 0.2 |
| Weight-for-age z score | − 0.26 ± 0.14 | − 0.04 ± 0.19 | 0.19 ± 0.15 | 0.12 ± 0.17 |
| Length-for-age z score | − 0.23 ± 0.12 | 0.15 ± 0.16 | −0.07 ± 0.14 | − 0.04 ± 0.17 |
| Age at first bottle, d | 101.7 ± 14.9 | 145.7 ± 24.2 | 103.1 ± 20.4 | 110.9 ± 18.9 |
| Intake of milk/formula, mL/d | 451.3 ± 58.9 | 366.5 ± 63.2 | 451.1 ± 73.5 | 391.7 ± 70.0 |
| Baseline developmental status | ||||
| Age at first test, mo | 7.5 ± 0.1 | 7.5 ± 0.1 | 7.5 ± 0.1 | 7.3 ± 0.2 |
| Mental raw score, points | 78.5 ± 0.9 | 76.9 ± 0.9 | 76.1 ± 0.7 | 75.7 ± 0.6 |
| Mental Development Index | 102.9 ± 3.2 | 101.6 ± 2.7 | 97.0 ± 2.5 | 97.7 ± 2.4 |
| Motor raw score, points | 29.9 ± 0.6 | 29.1 ± 0.7 | 28.9 ± 0.5 | 28.8 ± 0.6 |
| Motor Development Index | 94.7 ± 2.1 | 96.5 ± 2.5 | 94.7 ± 2.2 | 96.7 ± 2.3 |
| Behavior-rating scaleh | ||||
| Factor 1 | 0.01 ± 0.02 | 0.01 ± 0.03 | −0.02 ± 0.02 | − 0.01 ± 0.02 |
| Factor 2 | − 0.09 ± 0.04 | − 0.10 ± 0.05 | −0.12 ± 0.04 | − 0.11 ± 0.05 |
| Factor 3 | 0.11 ± 0.02 | 0.13 ± 0.02 | 0.09 ± 0.02 | 0.01 ± 0.03 |
| Factor 4a | − 0.11 ± 0.06 | − 0.11 ± 0.06 | 0.09 ± 0.06 | 0.12 ± 0.05 |
| No. of weekly visits before infant's last assessmenti | 29.6 ± 1.9 | 30.6 ± 1.4 | 30.1 ± 1.9 | 30.1 ± 1.9 |
Values are mean ± SE unless otherwise indicated. Behavior Rating Scale factor scores are expressed in SD units. Values for n are at enrollment (intention to treat); 1 infant with IDA and 2 nonanemic infants were removed before the baseline developmental assessment.
Values for the IDA group were significantly lower than those for the nonanemic group (P< .05), as tested by 2-way analysis of variance.
Measured by use of a short form of the Wechsler Adult Intelligence Scale, Revised.49
Measured by use of the Center for Epidemiologic Studies Depression Scale.50
Measured by use of the Graffar Scale,51 designed to differentiate families at the lower end of the socioeconomic spectrum.
Measured by use of a scale modified from Weinraub et al (1987).52
Measured by use of the Home Observation for Measurement of the Environment, Revised.53
More infants with IDA than infants without IDA were male (P = .01).
Behavior-Rating Scale factors consisted of the following scales: factor 1, energy, interest, initiative, exploration, attention, persistence, enthusiasm, and fearfulness; factor 2, gross-motor, fine-motor, movement control, hypotonicity, and slow movement; factor 3, negative affect, hypersensitivity, adaptation, frustration, orientation, and cooperation; and factor 4, positive affect, social referencing, and social engagement.
The number of visits before the second assessment was used if there was no third assessment.