TABLE 1

Demographic Characteristics of Children With and Without SSC at Age 7

CharacteristicControl Group, N = 183Case Group, N = 182
N%N%
Age, y
 <7.514478.712468.1
 >7.53921.35831.9
Gender
 Female6937.76837.4
 Male11462.311462.6
Grade levela
 <121.131.7
 113071.011060.4
 23720.25630.8
 ≥394.994.9
Race or ethnicityb
 Nonwhite or Hispanic4725.73720.3
 White, non-Hispanic13674.314579.7
SES
 I (highest)5329.04323.6
 II10255.78144.5
 III158.23619.8
 IV116.02011.0
 V (lowest)21.121.1
Site
 Seattle7138.87440.7
 Chicagoc7641.56636.3
 St Louis94.9189.9
 Atlanta2714.82413.2
  • a Grade level missing for 5 control and 4 case participants.

  • b Includes Hispanic or Latino ethnicity, Asian or Pacific Islander, black or African American, and mixed races or ethnicities.

  • c Includes children from Philadelphia, who were assessed by staff from the Chicago site.