Table 3.
Growth curve analyses for identification of variables longitudinally associated with physical activity in childrena
| Fixed effects | Model 1 | Model 2 | |
|---|---|---|---|
| Estimate (95% CI) | Initial PA, estimate (95% CI) | Change in PA,b estimate (95% CI) | |
| Intercept | 28.03 (27.62, 28.44) | 27.22 (26.36, 28.07 ) | |
| Time | −2.94 (−3.25, −2.63) | −2.87 (−3.12, −2.62) | |
| Sex, males | 0.19 (−0.63, 1.00) | ||
| Race | |||
| Black | 1.19 (0.57, 1.80) | ||
| Hispanic | 0.34 (−0.50, 1.18) | ||
| Other | 0.42 (−0.25, 1.08) | ||
| White | ref | ||
| Parent education, more than high school |
−0.99 (0.50, 1.47) | ||
| Percent poverty | −0.02 (−0.05, 0.02) | ||
| Maturity offset, 5th grade | −1.12 (−1.49, −0.75) | ||
| Self-efficacy | 0.21 (−0.42, 0.85) | 0.05 (−0.36, 0.45) | |
| Perceived barriers | 0.29 (−0.40, 0.98) | −0.17 (−0.59, 0.26) | |
| Self schema | 0.01 (−0.03, 0.04) | 0.003 (−0.02, 0.03) | |
| Appearance motivation | 0.23 (−0.16, 0.62) | 0.22 (−0.02, 0.46) | |
| Fitness motivation | −0.35 (−1.05, 0.36) | −0.33 (−0.77, 0.10) | |
| Parent rating of child’s PA | 0.86 (0.42, 1.31) | 0.05 (−0.23, 0.32) | |
| Sport/classes participation | 0.92 (0.25, 1.60) | −0.07 (−0.49, 0.36) | |
| Weekend day outdoor hours | 0.19 (0.05, 0.34) | −0.03 (−0.12, 0.06) | |
| How important that child is active | 0.52 (−0.03, 1.07) | −0.21 (−0.55, 0.13) | |
| Parent-reported support | 0.16 (−0.27, 0.60) | −0.03 (−0.31, 0.24) | |
| Parent leisure time | −0.45 (−0.92, 0.02) | 0.02 (−0.27, 0.31) | |
| Perceived environment | 0.01 (−0.48, 0.51) | −0.11 (−0.42, 0.21) | |
| Child-reported equipment |
0.00002 (−0.29, 0.29) | −0.08 (−0.26, 0.11) | |
| Rules on sedentary equipment | −0.11 (−0.52, 0.30) | 0.03 (−0.22, 0.29) | |
| Access to active equipment | −0.003 (−0.13, 0.12) | 0.04 (−0.03, 0.12) | |
| Child-reported parent support | 0.51 (0.10, 0.91) | −0.05 (−0.31, 0.20) | |
| Child-reported parent encouragement | −0.54 (−0.90, −0.18) | 0.27 (0.04, 0.49) | |
| Active friends | 0.12 (−0.11, 0.35) | −0.02 (−0.16, 0.12) | |
| Intramural activities, teacher reported | 0.32 (0.15, 0.50) | −0.28 (−0.42, −0.14) | |
| Social spaces (windshield survey) | −0.34 (−0.64, −0.04) | 0.32 (0.14, 0.51) | |
| PARA weighted score (2-mile buffer) |
0.01 (0.003, 0.02) | −0.003 (−0.01, 0.004) | |
| Goodness of fit | |||
| Deviance | 12,741.8 | 12,412.1 | |
| AIC | 12,757.8 | 12,526.1 | |
| BIC | 12,765.8 | 12,582.8 | |
Note: Boldface indicates statistical significance (p<0.05).
a
Variables were centered, and values reported are coefficients with 95% CI in parentheses estimated using full maximum likelihood.
b
From 5th to 7th grade
PA, physical activity; PARA, Physical Activity Resource Assessment; AIC, Akaike’s Information Criterion; BIC, Bayesian Information Criterion.