Table 1.
Bivariate Correlations
| Mean (SD)/n(%) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. Single item self-report | 2.85 (3.94) | 1 | |||||||||||
| 2. Average number of cigarettes per day across pregnancy (TLFB) | 3.56 (4.63) | 0.76** | 1 | ||||||||||
| 3. Maternal salivary cotinine across pregnancy | n = 141 (54.7%) positive | 0.57** | 0.64** | 1 | |||||||||
| 4. Infant meconium | n = 105 (51.7%) positive | 0.53** | 0.61** | 0.75** | 1 | ||||||||
| 5. Birthweight (kg) | 3233 (575.7) | −0.03 | −0.08 | −0.16* | −0.19** | 1 | |||||||
| 6. Head circumference (cm) | 33.95 (1.86) | −0.02 | −0.08 | −0.20** | −0.29** | 0.63** | 1 | ||||||
| 7. GA (weeks) | 38.94 (1.81) | 0.02 | −0.04 | −0.12 | −0.19** | 0.56** | 0.47** | 1 | |||||
| 8. Birth length (cm) | 50.10 (2.79) | −0.02 | −0.07 | −0.16* | −0.13 | 0.67** | 0.64** | 0.44** | 1 | ||||
| 9. Maternal Edu. | 12.32 (1.87) | −0.13* | −0.14* | −0.18** | −0.15* | 0.15* | 0.16* | 0.11 | 0.07 | 1 | |||
| 10.TANF | n = 36 (14%) receiving | 0.09 | 0.14* | 0.10 | 0.18* | −0.12 | −0.15* | −0.10 | −0.13* | −0.29** | 1 | ||
| 11. Race | n = 178 (69%) minority | 0.17** | 0.25** | 0.09 | 0.06 | 0.26** | 0.30** | 0.10 | 0.21** | 0.14* | −0.17** | 1 | |
| 12. Child sex | n = 134 (51.9%) male | −0.10 | −0.11 | −0.06 | −0.06 | −0.10 | −0.10 | −0.06 | −0.12 | 0.04 | 0.02 | −0.06 | 1 |
Edu. = Education; GA = Gestational Age; SD = standard deviation; TANF = Temporary Assistance for Needy Families; TLFB = Timeline Follow Back. Bivariate n’s ranged from 199 to 258 due to missing data on meconium and head circumference as described in the methods section. Incidence of preterm birth in smoking mothers was 6% when smoking status was determined by single item self-report (n = 258), 7.7% when identified using the TLFB (n = 258) 7.8% when identified by maternal saliva (n = 258), 7.6% when identified by infant meconium (n = 203).
*p < .05. **p < .01.