Table 2.
Description of Sample and Analysis Variables
| Variable | NICHD Study of Early Child Care |
Focus on infant-toddler care | Focus on preschool care | Focus on both infant-toddler and preschool care | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Early low | Early high | Late low | Late high | Low-low | High-low | Low-high | High-high | ||||
| Child outcomes: M (SD) | |||||||||||
| Cognitive development at 24 mo. | 0.00 (1.00) | 0.02 (0.94) | 0.32 (0.92) | 0.09 (0.98) | 0.23 (0.92) | −0.04 (0.98) | 0.34 (0.95) | 0.15 (0.86) | 0.39 (0.87) | ||
| Memory for sentences at 54 mo. | 0.00 (1.00) | −0.05 (0.98) | 0.27 (0.95) | −0.11 (0.96) | 0.19 (0.94) | 0.05 (0.96) | 0.29 (0.97) | ||||
| Language comprehension at 54 mo. | 0.00 (1.00) | −0.14 (0.99) | 0.36 (0.84) | −0.17 (0.97) | 0.10 (0.92) | 0.12 (0.95) | 0.48 (0.82) | ||||
| Letter–word identification at 54 mo. | 0.00 (1.00) | −0.10 (0.97) | 0.35 (0.95) | −0.17 (0.96) | 0.10 (0.90) | 0.14 (0.96) | 0.48 (0.99) | ||||
| Applied problems at 54 mo. | 0.00 (1.00) | −0.11 (0.99) | 0.30 (0.88) | −0.19 (0.94) | 0.06 (0.97) | 0.10 (0.96) | 0.43 (0.89) | ||||
| Family characteristics | |||||||||||
| At 1 mo. after birth | |||||||||||
| Maternal age (years): M (SD) | 29.59 (4.77) | 28.80 (5.25) | 29.41 (4.91) | 29.08 (5.15) | 29.47 (5.29) | 28.42 (5.04) | 29.49 (4.69) | 29.60 (5.37) | 29.65 (4.99) | ||
| Maternal education (years): M (SD) | 15.12 (2.28) | 14.46 (2.16) | 15.19 (2.53) | 14.44 (2.45) | 15.08 (2.28) | 14.19 (2.09) | 15.03 (2.61) | 15.09 (2.15) | 15.50 (2.34) | ||
| Maternal paid leave: % | 67 | 60 | 65 | 59 | 49 | 68 | 65 | 57 | 68 | ||
| Maternal child-rearing attitudes: M (SD) | 70.62 (15.04) | 73.83 (15.93) | 70.73 (15.10) | 74.42 (15.93) | 70.05 (15.23) | 74.91 (15.07) | 73.00 (14.93) | 70.01 (15.44) | 68.18 (14.90) | ||
| Paternal education (years): M (SD) | 15.06 (2.57) | 14.37 (2.42) | 15.07 (2.68) | 14.40 (2.44) | 15.32 (2.64) | 14.05 (2.20) | 14.73 (2.54) | 15.15 (2.57) | 15.49 (2.64) | ||
| Maternal separation anxiety: M (SD) | 66.45 (12.39) | 67.94 (13.01) | 67.01 (12.33) | 66.59 (12.66) | 66.37 (12.77) | 68.96 (12.76) | 66.76 (11.78) | ||||
| Mother has a job: % | 81 | 74 | 81 | 82 | 85 | 71 | 82 | ||||
| Maternal depression: M (SD) | 10.22 (8.19) | 11.22 (8.59) | 11.53 (8.78) | 10.89 (8.61) | 10.93 (9.69) | 10.82 (7.89) | 10.50 (8.36) | ||||
| Partner in household: % | 97 | 95 | 98 | 94 | 97 | 95 | 98 | ||||
| Family income-to-needs ratio: M (SD) | 3.43 (2.80) | 2.89 (2.58) | 3.52 (2.69) | 2.66 (2.24) | 3.28 (2.33) | 3.45 (3.14) | 3.88 (3.02) | ||||
| At 24 mo. of age | |||||||||||
| Maternal separation anxiety: M (SD) | 59.73 (12.42) | 61.48 (13.00) | 61.68 (12.92) | ||||||||
| Mother has a job: % | 89 | 80 | 71 | ||||||||
| Maternal depression: M (SD) | 8.34 (7.38) | 9.87 (9.14) | 8.81 (7.81) | ||||||||
| Partner in household: % | 93 | 88 | 93 | ||||||||
| Family income-to-needs ratio: M (SD) | 4.67 (3.38) | 3.91 (3.15) | 4.40 (3.18) | ||||||||
| Child characteristics | |||||||||||
| At 1 mo. after birth | |||||||||||
| Gender (1 = male): % | 48 | 50 | 49 | 48 | 48 | 51 | 43 | 44 | 51 | ||
| Ethnicity: White/non-Hispanic: % | 88 | 84 | 89 | 86 | 87 | 84 | 88 | 86 | 90 | ||
| Difficult temperament: M (SD) | 3.31 (0.63) | 3.30 (0.62) | 3.34 (0.67) | 3.25 (0.65) | 3.34 (0.64) | 3.26 (0.60) | 3.28 (0.69) | 3.34 (0.66) | 3.38 (0.62) | ||
| Child’s birth order: M (SD) | 1.66 (0.79) | 1.78 (0.86) | 1.63 (0.80) | 1.82 (0.87) | 1.77 (0.90) | 1.78 (0.83) | 1.70 (0.78) | 1.71 (0.84) | 1.54 (0.76) | ||
| Health of baby: M (SD) | 3.72 (0.51) | 3.68 (0.53) | 3.73 (0.50) | 3.65 (0.54) | 3.70 (0.52) | 3.75 (0.49) | 3.75 (0.49) | ||||
| At 24 mo. of age | |||||||||||
| Health of baby: M (SD) | 3.18 (0.71) | 3.20 (0.68) | 3.22 (0.72) | ||||||||
| Sample size | 1,364 | 475 | 412 | 511 | 474 | 251 | 162 | 139 | 186 | ||
| Proportion of sample | 100% | 35% | 30% | 37% | 35% | 18% | 12% | 10% | 14% | ||
Note. NICHD = National Institute of Child Health and Human Development.