Table. Descriptive Statistics of Study Variables and Associations of BLL With Offending Outcomesa.
| Measure | Descriptive Statistics (N = 553) | Descriptive Statistics by BLL Category | Association With BLL (95% CI)b | ||||||
|---|---|---|---|---|---|---|---|---|---|
| ≤5 μg/dL (n = 33) | 6-10 μg/dL (n = 265) | 11-15 μg/dL (n = 173) | >15 μg/dL (n = 82) | Unadjusted | P Value | Adjusted for Male Sexc | P Value | ||
| Childhood BLL, mean (SD), μg/dL | 11.01 (4.62) | NA | NA | NA | NA | NA | NA | NA | NA |
| Criminal conviction, No. (%) | |||||||||
| No | 399 (72.2) | 25 (75.8) | 204 (77.0) | 112 (64.7) | 58 (70.7) | 1 [Reference] | NA | 1 [Reference] | NA |
| Yes | 154 (27.8) | 8 (24.2) | 61 (23.0) | 61 (35.3) | 24 (29.3) | 1.29 (1.06-1.56) | .01d | 1.23 (1.00-1.51) | .05 |
| Conviction subgroup comparison 1, No. (%) | |||||||||
| One-time offender | 68 (12.3) | 2 (6.1) | 29 (10.9) | 26 (15.0) | 11 (13.4) | 1.29 (0.99-1.68) | .06 | 1.25 (0.95-1.64) | .11 |
| Recidivistic offender | 86 (15.6) | 6 (18.2) | 32 (12.1) | 35 (20.2) | 13 (15.9) | 1.28 (1.01-1.63) | .046d | 1.21 (0.93-1.57) | .15 |
| Conviction subgroup comparison 2, No. (%) | |||||||||
| Nonviolent offender | 101 (18.3) | 5 (15.2) | 40 (15.1) | 38 (22.0) | 18 (22.0) | 1.33 (1.06-1.67) | .01d | 1.28 (1.01-1.61) | .04d |
| Violent offender | 53 (9.6) | 3 (9.1) | 21 (7.9) | 23 (13.3) | 6 (7.3) | 1.20 (0.89-1.62) | .24 | 1.13 (0.82-1.55) | .45 |
| Self-reported offending variety, mean (SD), No. | |||||||||
| Age 15 y | 1.99 (2.82) | 1.39 (2.34) | 1.79 (2.77) | 2.17 (2.83) | 2.49 (3.04) | 0.10 (0.02-0.19) | .02d | 0.10 (0.01-0.18) | .02d |
| Age 18 y | 4.24 (3.15) | 3.25 (2.69) | 4.06 (3.02) | 4.54 (3.33) | 4.64 (3.25) | 0.09 (0.00-0.17) | .04d | 0.06 (–0.02 to 0.14) | .16 |
| Age 21 y | 4.22 (3.02) | 3.82 (2.51) | 4.15 (2.92) | 4.30 (3.21) | 4.49 (3.15) | 0.04 (–0.04 to 0.13) | .30 | 0.01 (–0.06 to 0.09) | .75 |
| Age 26 y | 2.83 (2.55) | 2.03 (1.49) | 2.58 (2.40) | 3.27 (2.74) | 3.01 (2.78) | 0.09 (0.01-0.17) | .03d | 0.06 (–0.02 to 0.13) | .15 |
| Age 32 y | 2.25 (2.19) | 1.50 (1.83) | 2.03 (1.83) | 2.80 (2.54) | 2.08 (2.37) | 0.08 (–0.01 to 0.16) | .08 | 0.04 (–0.04 to 0.12) | .28 |
| Age 38 y | 1.10 (1.59) | 0.74 (0.73) | 1.01 (1.49) | 1.36 (1.88) | 0.99 (1.44) | 0.04 (0.04-0.12) | .32 | 0.02 (–0.06 to 0.10) | .66 |
| Sex, No. (%) | |||||||||
| Female | 255 (46.1) | 17 (51.5) | 137 (51.7) | 68 (39.3) | 33 (40.2) | 1 [Reference] | NA | NA | NA |
| Male | 298 (53.9) | 16 (48.5) | 128 (48.3) | 105 (60.7) | 49 (59.8) | 0.10 (0.02-0.18) | .02d | NA | NA |
Abbreviations: BLL, blood lead level; NA, not applicable.
SI conversion factor: To convert lead to micromoles per liter, multiply by 0.0483.
Full sample, N = 553. Age 15 years, n = 543; age 18 years, n = 535; age 21 years, n = 541; age 26 years, n = 543; age 32 years, n = 542; and age 38 years, n = 540.
For conviction, odds ratio from logistic regression of conviction on BLL in 5-μg/dL units; reference category is no conviction. For conviction subgroups, odds ratios from multinomial logistic regression models of subgroup on BLL in 5-μg/dL units; reference category is no conviction. For variety of self-reported offenses, standardized β coefficients reported for offending variety regressed on BLL; these estimates can be interpreted as correlation coefficients (r).
Model fit was significantly improved by adjusting for all but variety of self-reported offenses at 15 years of age.
P < .05.