Table 2.
Descriptive Statistics of Explanatory and Outcome Variables (n=1,208)
| Variable | Mean | Std. Dev. | Min | Max |
|---|---|---|---|---|
| Demographic characteristics | ||||
| Gender (female) | .52 | .50 | 0 | 1 |
| Race/ethnicity (African-American) | .94 | .24 | 0 | 1 |
| Early and middle childhood factors | ||||
| CPC preschool participation (ages 3-4) | .65 | .48 | 0 | 1 |
| Child protection services (ages 4-9) | .10 | .30 | 0 | 1 |
| Family conflict (ages 5-10) | .06 | .24 | 0 | 1 |
| Parent substance abuse experience (ages 5-10) | .05 | .21 | 0 | 1 |
| School mobility (ages 6-9) | .74 | .85 | 0 | 4 |
| CPC school-age participation (ages 6-9) | .57 | .50 | 0 | 1 |
| Social maturity (ages 7-9) | 19.31 | 4.71 | 7 | 30 |
| Family risk (age 8) | 4.23 | 1.79 | 0 | 8 |
| Parent expectations (ages 8-10) | 3.39 | .87 | 1 | 5 |
| Intrinsic motivation (ages 9-10) | −.01 | .79 | −3.2 | 1.7 |
| No trouble-making behavior (ages 9-12) | 6.06 | 1.76 | 1 | 12 |
| Reading achievement (age 10) | 102.83 | 14.66 | 53 | 150 |
| Adolescence factors | 0 | |||
| School mobility (ages 10-14) | .97 | .99 | 0 | 4 |
| School quality (ages 10-14) | .13 | .34 | 0 | 1 |
| Parent substance abuse experience (ages 10-15) | .09 | .28 | 0 | 1 |
| Personal substance use experience (ages 10-15) | .03 | .17 | 0 | 1 |
| School mobility (ages 14-18) | .21 | .48 | 0 | 3 |
| Deviant peer affiliation (age 16) | .39 | .49 | 0 | 1 |
| School dropout (by age 16) | .13 | .33 | 0 | 1 |
| Outcomes | ||||
| Age of first substance use | 17.21 | 3.20 | 9 | 26 |
| Substance abuse | .26 | .44 | 0 | 1 |
| Substance dependency (among those with use)1 | .38 | .49 | 0 | 1 |
| Length of time from use to dependency (in years)2 | 5.49 | 2.97 | 3 | 16 |
1
Dichotomous variable that takes a value of 1 if the individual was classified as drug dependent and 0 otherwise (sample size is 440).
2
Information was available for one-year, two-year or four-year periods. When a participant satisfied the definition for dependency, he/she was classified as substance dependent for the whole period (e.g. 4 years). The sample size for length of time from use to dependency includes only participants who were classified as substance dependent (n=168).
CPC = Child-Parent Center program