Appendix Table 1.
List of Potential Variables for Linear Regression, Northern California Childhood Leukemia Study, 1999-2007
| Variable Group | Variable | Unit |
| Self-reported smoking | Lifetime smoking status of mother | Dichotomous |
| Smoking status of mother 3 months before conception | Dichotomous | |
| Smoking status of mother while pregnant | Dichotomous | |
| Smoking status of mother after birth | Dichotomous | |
| Smoking status of mother at initial interview | Dichotomous | |
| Cigarette consumption of mother 3 months before conception | Continuous (cigarettes/day) | |
| Cigarette consumption of mother while pregnant | Continuous (cigarettes/day) | |
| Cigarette consumption of mother after birth | Continuous (cigarettes/day) | |
| Lifetime smoking status of father | Dichotomous | |
| Smoking status of father 3 months before conception | Dichotomous | |
| Smoking status of father at initial interview | Dichotomous | |
| Cigarette consumption of father 3 months before conception | Continuous (cigarettes/day) | |
| Smoking status of others in the house before birth | Dichotomous | |
| Smoking status of others in the house after birth | Dichotomous | |
| Household cigarette consumption during the month before dust collection | Continuous (cigarettes/day) | |
| Parental demographics | Mother's age | Continuous (years) |
| Father's age | Continuous (years) | |
| Mother's education | Categorical | |
| Father's education | Categorical | |
| Household annual income | Categorical | |
| House characteristics | Residence is apartment | Dichotomous |
| Residence is townhouse | Dichotomous | |
| Residence is mobile home | Dichotomous | |
| Age of residence | Categorical | |
| Child-specific variables | Case-control status | Dichotomous |
| Sex | Dichotomous | |
| Age at reference date | Continuous (years) | |
| Down syndrome status | Dichotomous | |
| Birth weight | Continuous (g) | |
| Breastfeeding duration | Continuous (months) | |
| Sampling conditions | Sampling method | Dichotomous |
| Sampling temperature | Continuous (°Fa) | |
| Sampling humidity | Continuous (% relative humidity) | |
| Size of sampling area | Continuous (m2) | |
| Age of carpet sampled | Continuous (years) | |
| Room throughway distinction | Dichotomous | |
| Vacuum use frequency | Categorical | |
| Interview respondent | Dichotomous | |
| Time effects | Time from diagnosis to initial interview | Continuous (days) |
| Time from diagnosis to dust collection | Continuous (days) | |
| Year of dust collection | Continuous | |
| Season is spring | Dichotomous | |
| Season is summer | Dichotomous | |
| Season is fall | Dichotomous | |
| Residence stability | Continuous (years) | |
| Ethnicity | Child is white | Dichotomous |
| Child is other ethnicity | Dichotomous | |
| Mother is white | Dichotomous | |
| Mother is other ethnicity | Dichotomous | |
| Father is white | Dichotomous | |
| Father is other ethnicity | Dichotomous |
a
°C = (5/9)(°F – 32).