Sample descriptions by survey year
| Survey year | p Values for tests of difference | |||||
|---|---|---|---|---|---|---|
| 2007 (n=1612) | 2008 (n=1605) | 2014 (n=1601) | Comparison between years | Schools who did versus did not participate in 2014 (2008 data) | Original versus replacement schools (2014 data) | |
| Boys | 778 (48.5) | 792 (49.4) | 797 (49.8) | 0.80 | 0.53 | 0.75 |
| Mean (SD) age | 10.9 (0.4) | 10.9 (0.4) | 10.9 (0.4) | 0.42 | 0.71 | 0.54 |
| Mean (SD) FAS score | 5.6 (1.9) | 5.7 (1.9) | 6.6 (1.9) | <0.001 | 0.43 | 0.90 |
| Mean (SD) FAS score without computers | 3.9 (1.5) | 3.9 (1.4) | 3.9 (1.4) | 0.41 | 0.93 | 0.71 |
| Two parent families | 1120 (69.5) | 1089 (67.9) | 1074 (67.1) | 0.37 | 0.12 | 0.57 |
| Step families | 170 (10.6) | 175 (10.9) | 152 (9.4) | |||
| Single mother | 263 (16.3) | 273 (17.0) | 282 (17.6) | |||
| Single father | 18 (1.1) | 23 (1.4) | 32 (2.0) | |||
| Self-reported smokers | 24 (1.5) | 18 (1.1) | 12 (0.8) | 0.19 | 0.28 | 0.30 |
Figures are frequencies (and percentages) unless otherwise indicated.
p values for design adjusted χ2 analyses, except for age (t test).
FAS, Family Affluence Scale.