Table 3.
Means (Standard Deviations) and Intraclass Correlations of Study Outcome Measures and Model Statistics Comparing the Trends Between Control (C) and Intervention Schools (I) over Six Measurement Time Points
| Year 1 baseline (month 1) | Year 1 posttest (month 9) | Year 2 baseline (month 13) | Year 2 posttest (month 20) | Year 3 baseline (month 24) | Year 3 posttest (month 33) | ICC | F/pvalue for treatment – time interaction term | ||
|---|---|---|---|---|---|---|---|---|---|
| Percent body fat | C | 26.66 (9.69) | 26.96 (9.70) | 27.56 (9.48) | 27.73 (9.42) | 29.05 (9.74) | 27.44 (9.40) | 0.94 | F=3.10 |
| (%)a | I | 26.00 (9.07) | 25.53 (9.27) | 26.89 (9.59) | 26.32 (10.04) | 28.15 (10.37) | 27.23 (9.84) | p=0.009 | |
| Contrast estimate (SE) | −0.33 (0.21) | 0.03 (0.28) | −0.44 (0.19) | 0.26 (0.38) | 0.54 (0.43) | ||||
| p value | 0.11 | 0.91 | 0.19 | 0.49 | 0.21 | ||||
| Cardiorespiratory | C | 162.17 (17.46) | 160.52 (15.72) | 161.83 (17.04) | 159.25 (18.44) | 162.2 (19.21) | 160.55 (17.84) | 0.58 | F=4.74 |
| fitness (bpm)b,c | I | 159.25 (17.84) | 154.06 (20.31) | 161.45 (18.33) | 156.98 (20.53) | 162.81 (21.61) | 158.26 (19.20) | p<0.001 | |
| Contrast estimate (SE) | −2.87 (1.39) | 2.87 (1.53) | 1.39 (1.58) | 4.32 (1.65) | 0.70 (1.65) | ||||
| p value | 0.039 | 0.062 | 0.38 | 0.009 | 0.67 | ||||
| Weight (kg)a,e | C | 34.30 (10.28) | 37.14 (11.38) | 39.18 (11.58) | 42.24 (12.87) | 44.81 (13.88) | 47.83 (14.88) | 0.95 | F=1.92 |
| I | 34.74 (11.39) | 37.06 (12.35) | 40.21 (13.53) | 43.22 (14.92) | 46.03 (16.20) | 49.77 (17.02) | p=0.09 | ||
| Contrast estimate (SE) | –0.24 (0.20) | 0.23 (0.30) | 0.29 (0.40) | 0.83 (0.50) | 1.01 (0.59) | ||||
| p value | 0.24 | 0.45 | 0.47 | 0.095 | 0.087 | ||||
| Height (cm)d,e | C | 133.03 (6.72) | 136.57 (7.01) | 138.96 (7.17) | 143.03 (7.58) | 145.65 (7.68) | 149.53 (8.02) | 0.96 | F=0.94 |
| I | 133.55 (7.81) | 137.26 (8.27) | 140.41 (8.58) | 144.39 (8.66) | 146.77 (8.72) | 151.20 (8.85) | p=0.45 | ||
| Contrast estimate (SE) | 0.09 (0.11) | 0.16 (0.17) | 0.22 (0.22) | 0.04 (0.27) | 0.18 (0.32) | ||||
| p value | 0.40 | 0.33 | 0.31 | 0.88 | 0.58 | ||||
| BMI z-scoree | C | 0.78 (1.07) | 0.78 (1.10) | 0.74 (1.09) | 0.76 (1.10) | 0.76 (1.13) | 0.70 (1.13) | 0.96 | F=1.78 |
| I | 0.76 (1.10) | 0.67 (1.11) | 0.69 (1.21) | 0.67 (1.19) | 0.71 (1.25) | 0.72 (1.17) | p=0.12 | ||
| Contrast estimate (SE) | −0.04 (0.02) | –0.03 (0.03) | –0.03 (0.04) | 0.02 (0.04) | 0.05 (0.05) | ||||
| p value | 0.075 | 0.30 | 0.39 | 0.62 | 0.28 | ||||
| Waist circumference | C | 62.37 (10.36) | 63.98 (10.86) | 65.32 (10.81) | 67.37 (12.92) | 67.72 (11.86) | 67.51 (11.64) | 0.90 | F=2.52 |
| (cm)e | I | 62.67 (10.86) | 63.62 (11.11) | 65.85 (12.24) | 67.31 (12.96) | 68.74 (14.18) | 68.90 (13.27) | p=0.03 | |
| Contrast estimate (SE) | −0.26 (0.42) | 0.17 (0.50) | −0.53 (0.53) | 0.89 (0.50) | 1.05 (0.58) | ||||
| p value | 0.54 | 0.73 | 0.32 | 0.073 | 0.072 | ||||
| TC/HDL ratioc | C | 2.89 (0.71) | 3.28 (0.90) | 3.64 (1.27) | 3.68 (1.23) | 3.59 (1.16) | 3.44 (1.07) | 0.49 | F=0.45 |
| I | 3.04 (0.93) | 3.30 (1.16) | 3.65 (1.22) | 3.69 (1.20) | 3.69 (1.35) | 3.61 (1.53) | p=0.82 | ||
| Contrast estimate (SE) | −l0.06 (0.11) | −0.05 (0.12) | −0.10 (0.12) | 0.05 (0.12) | 0.03 (0.12) | ||||
| p value | 0.55 | 0.66 | 0.41 | 0.68 | 0.80 | ||||
| Systolic blood | C | 110.30 (9.02) | 107.79 (9.36) | 108.97 (9.96) | 108.98 (8.16) | 108.31 (8.94) | 110.98 (8.62) | 0.55 | F=1.47 |
| pressure (mmHg)b,d | I | 110.60 (9.55) | 106.60 (10.17) | 109.93 (9.26) | 109.28 (9.63) | 109.29 (8.89) | 111.48 (9.49) | p=0.20 | |
| Contrast estimate (SE) | −1.17 (0.75) | 1.10 (0.84) | −0.12 (0.87) | −0.06 (0.87) | −0.25 (0.92) | ||||
| p value | 0.12 | 0.19 | 0.89 | 0.94 | 0.79 | ||||
| Diastolic blood | C | 66.14 (4.97) | 64.69 (5.59) | 65.42 (5.76) | 65.57 (5.11) | 64.78 (4.95) | 66.04 (4.78) | 0.42 | F=0.75 |
| pressure (mmHg)d | I | 65.89 (5.21) | 63.84 (6.35) | 65.15 (6.11) | 65.10 (5.33) | 65.08 (5.08) | 66.06 (5.58) | p=0.59 | |
| Contrast estimate (SE) | −0.52 (0.50) | 0.17 (0.55) | −0.36 (0.56) | 0.44 (0.57) | 0.04 (0.55) | ||||
| p value | 0.29 | 0.77 | 0.52 | 0.44 | 0.94 |
Model adjusted for sex, race, age, economic disadvantage status, and their interactions with intervention status. Only significant effects are included in the model. A priori contrasts were used to compare the changes from year 1 pretest (month 0) at each time point.
a
Male<female; bMale>female; cWhite>non-white; dWhite<non-white; eIncreases with age.
SE, Standard error; bpm, beats per minute;TC, total cholesterol; HDL-C, high-density lipoprotein cholesterol.