Bivariate Associations Between Potential Confounders and the Study’s Dependent, Independent, and Moderator Variables
| CCS Intensity Sample (n = 1269) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dependent Variables: 12-y Government Examinations | Independent Variable: CCS Intensity Trajectories | Moderator: SES | |||||||||||
| Reading | Writing | Mathematics | Low Hours (n = 416) | Moderate Hours (n = 394) | High Hours (n = 459) | P | Adequate SES (n = 941) | Low SES (n = 328) | P | ||||
| r | P | r | P | r | P | ||||||||
| Reading | — | — | — | — | — | — | 60.01 (28.13) | 61.62 (26.74) | 66.47 (23.41) | .001 | 67.73 (23.22) | 48.85 (29.09) | <.001 |
| Writing | — | — | — | — | — | — | 61.00 (27.68) | 64.72 (25.17) | 70.31 (22.76) | <.001 | 70.43 (22.20) | 51.45 (28.87) | <.001 |
| Mathematics | — | — | — | — | — | — | 62.36 (28.83) | 64.92 (26.45) | 69.96 (23.58) | <.001 | 70.59 (23.21) | 52.47 (30.35) | <.001 |
| CCS intensity trajectories | 0.10 | <.001 | 0.15 | <.001 | 0.12 | <.001 | — | — | — | — | 2.19 (0.81) | 1.60 (0.72) | <.001 |
| Gender | –0.16 | <.001 | –0.23 | <.001 | –0.09 | .003 | 0.53 (0.50) | 0.50 (0.50) | 0.56 (0.50) | .27 | 0.54 (0.50) | 0.51 (0.50) | .48 |
| Birth order | –0.05 | .12 | –0.08 | .01 | –0.08 | .01 | 1.91 (0.96) | 1.68 (0.79) | 1.62 (0.73) | <.001 | 1.72 (0.79) | 1.79 (0.95) | .20 |
| Family status | 0.17 | <.001 | 0.18 | <.001 | 0.19 | <.001 | 0.78 (0.42) | 0.80 (0.40) | 0.84 (0.37) | .08 | 0.88 (0.33) | 0.61 (0.49) | .00 |
| CSNR | –0.06 | .05 | –0.06 | .07 | –0.05 | .12 | 0.94 (1.19) | 0.85 (1.18) | 0.90 (1.13) | .51 | 0.85 (1.16) | 1.04 (1.18) | .02 |
| Difficult temperament | 0.07 | .01 | 0.08 | .008 | 0.06 | .03 | 2.64 (1.62) | 2.77 (1.57) | 2.73 (1.56) | .51 | 2.73 (1.59) | 2.68 (1.55) | .66 |
| Maternal age | 0.16 | <.001 | 0.14 | <.001 | 0.11 | <.001 | 28.64 (5.93) | 28.18 (5.31) | 30.02 (4.71) | <.001 | 29.91 (4.76) | 26.37 (6.13) | <.001 |
| Family dysfunction | –0.09 | .003 | –0.09 | .002 | –0.08 | .006 | 1.80 (1.42) | 1.70 (1.36) | 1.62 (1.41) | .20 | 1.55 (1.31) | 2.15 (1.55) | <.001 |
| Neighborhood safety | –0.08 | .007 | –0.10 | <.001 | –0.09 | .002 | 1.88 (0.64) | 1.84 (0.64) | 1.73 (0.56) | <.001 | 1.76 (0.59) | 1.98 (0.65) | <.001 |
| Social problems in neighborhood | 0.08 | .007 | 0.11 | <.001 | 0.10 | 0.001 | 2.73 (0.42) | 2.78 (0.35) | 2.84 (0.30) | <.001 | 2.83 (0.31) | 2.67 (0.45) | <.001 |
| T1—SES Factor | –0.32 | <.001 | –0.33 | <.001 | –0.30 | <.001 | 0.43 (0.50) | 0.27 (0.44) | 0.10 (0.30) | <.001 | — | — | — |
| T1—Positive parenting factor | 0.01 | .74 | 0.01 | .68 | 0.00 | .87 | –0.03 (0.39) | –0.02 (0.34) | –0.07 (0.35) | .09 | –0.04 (0.35) | –0.04 (0.39) | .74 |
| T1—Negative parenting factor | –0.06 | .06 | –0.05 | .08 | –0.03 | .25 | 0.05 (0.66) | 0.08 (0.60) | 0.05 (0.61) | .83 | 0.06 (0.60) | 0.07 (0.69) | .71 |
| T1—Family deviancy factor | –0.06 | .06 | –0.07 | .02 | –0.05 | .11 | 0.01 (0.19) | 0.02 (0.21) | 0.00 (0.19) | .60 | –0.01 (0.18) | 0.06 (0.23) | <.001 |
| T1—Parent mental health factor | –0.16 | <.001 | –0.17 | <.001 | –0.16 | <.001 | 0.10 (0.58) | 0.04 (0.54) | –0.08 (0.51) | <.001 | –0.09 (0.51) | 0.31 (0.56) | <.001 |
| T1—Child peer relationships factor | 0.09 | .004 | 0.09 | .003 | 0.10 | <.001 | –0.02 (0.33) | –0.03 (0.29) | 0.00 (0.29) | .36 | 0.00 (0.30) | –0.05 (0.32) | .01 |
| Center-Based CCS Sample (n = 1119) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dependent Variables: 12-y Government Examinations | Independent Variable: Center-Based CCS Trajectories | Moderator: SES | |||||||||||
| Reading | Writing | Mathematics | Never CB CCS (n = 694) | Late-Onset CB CCS (n = 292) | Early-Onset CB CCS (n = 133) | P | Adequate (n = 876) | Low (n = 243) | P | ||||
| r | P | r | P | r | P | ||||||||
| Reading | — | — | — | — | — | — | 64.47 (25.61) | 62.66 (25.37) | 62.38 (25.86) | .47 | 67.45 (23.36) | 50.37 (28.61) | <.001 |
| Writing | — | — | — | — | — | — | 66.99 (24.84) | 66.10 (24.91) | 67.43 (24.91) | .80 | 70.39 (22.38) | 53.88 (28.78) | <.001 |
| Mathematics | — | — | — | — | — | — | 67.19 (25.80) | 65.53 (25.61) | 68.11 (25.83) | .53 | 70.62 (23.26) | 53.33 (29.53) | <.001 |
| CB CCS Trajectories | –0.03 | .28 | 0.00 | .94 | 0.00 | .92 | — | — | — | — | 1.52 (0.71) | 1.40 (0.64) | .02 |
| Gender | –0.16 | <.001 | –0.23 | <.001 | –0.08 | .01 | 0.52 (0.50) | 0.55 (0.50) | 0.50 (0.50) | .63 | 0.54 (0.50) | 0.47 (0.50) | .05 |
| Birth order | –0.02 | .57 | –0.05 | .11 | –0.05 | .11 | 1.68 (0.80) | 1.68 (0.72) | 1.82 (0.98) | .17 | 1.70 (0.78) | 1.70 (0.91) | .90 |
| Family status | 0.16 | <.001 | 0.15 | <.001 | 0.19 | <.001 | 0.84 (0.37) | 0.80 (0.40) | 0.76 (0.43) | .07 | 0.88 (0.33) | 0.60 (0.49) | <.001 |
| CSNR | –0.05 | .17 | –0.04 | .28 | –0.03 | .31 | 0.93 (1.17) | 0.81 (1.17) | 0.80 (1.13) | .19 | 0.85 (1.17) | 1.01 (1.13) | .06 |
| Difficult Temperament | 0.08 | .01 | 0.07 | .02 | 0.07 | .03 | 2.73 (1.63) | 2.78 (1.64) | 2.69 (1.34) | .80 | 2.73 (1.60) | 2.78 (1.59) | .71 |
| Maternal age | 0.17 | <.001 | 0.16 | <.001 | 0.12 | <.001 | 28.76 (5.32) | 29.26 (5.11) | 29.86 (5.60) | .06 | 29.85 (4.70) | 26.03 (6.25) | <.001 |
| Family dysfunction | –0.07 | .03 | –0.07 | .03 | –0.06 | .07 | 1.63 (1.42) | 1.69 (1.35) | 1.83 (1.37) | .20 | 1.55 (1.30) | 2.10 (1.63) | <.001 |
| Neighborhood safety | –0.07 | .02 | –0.10 | .003 | –0.09 | .01 | 1.79 (0.61) | 1.82 (0.61) | 1.76 (0.57) | .57 | 1.76 (0.59) | 1.93 (0.65) | <.001 |
| Social problems in neighborhood | 0.09 | .003 | 0.12 | <.001 | 0.12 | <.001 | 2.80 (0.35) | 2.78 (0.37) | 2.77 (0.33) | .56 | 2.82 (0.31) | 2.67 (0.45) | <.001 |
| T1—SES factor | –0.28 | <.001 | –0.27 | <.001 | –0.28 | <.001 | 0.24 (0.43) | 0.20 (0.40) | 0.15 (0.36) | .06 | — | — | — |
| T1—Positive parenting factor | 0.03 | .34 | 0.03 | .31 | 0.01 | .64 | –0.03 (0.35) | –0.08 (0.35) | –0.07 (0.36) | .11 | –0.04 (0.35) | –0.08 (0.36) | .12 |
| T1—Negative parenting factor | –0.08 | .01 | –0.08 | .01 | –0.04 | .18 | 0.04 (0.60) | 0.14 (0.62) | 0.07 (0.64) | .04 | 0.05 (0.59) | 0.13 (0.67) | .08 |
| T1—Family deviancy factor | –0.06 | .09 | –0.07 | .04 | –0.05 | .14 | 0.01 (0.20) | 0.01 (0.20) | 0.01 (0.20) | .99 | –0.01 (0.18) | 0.08 (0.25) | <.001 |
| T1—Parent mental health factor | –0.15 | <.001 | –0.16 | <.001 | –0.16 | <.001 | –0.04 (0.51) | 0.09 (0.59) | 0.04 (0.62) | .003 | –0.09 (0.51) | 0.35 (0.56) | <.001 |
| T1—Child peer relationships factor | 0.09 | .004 | 0.10 | .002 | 0.10 | .003 | 0.00 (0.30) | –0.04 (0.31) | –0.05 (0.32) | .07 | 0.00 (0.30) | –0.08 (0.32) | <.001 |
Data are presented as r, mean, and SD. The center-based (CB) CCS sample eliminates those who remained in parental care (n = 150), thus comparing only children who attend CCS. Among the variables tested as potential selection bias factors, only the positive parenting factor was not related to child care, SES, or academic achievement. It was thus dropped from our analyses, leaving 14 confound variables in the analyses. Also, children in either child-care trajectory (independent variables) differed on 1 individual (birth order) and 6 family variables (maternal age, neighborhood safety, social problems in neighborhood, SES, negative parenting, and parental mental health); T1, Time 1, 5 months to 5 years. These 7 selection bias variables were used as controls in the analyses. —, not applicable.