Table 3.
Demographic and residential characteristics of 252 childhood ALL cases and 306 controls in the California Childhood Leukemia Studya, 2001–2007
| Children’s Characteristics | Cases n (%) | Controls n (%) | p-valueh |
|---|---|---|---|
| Sex | |||
| Male | 146 (57.9) | 181 (59.1) | 0.77 |
| Female | 106 (42.1) | 125 (40.9) | |
| Age, years (mean ±SD) | 4.0 ±1.8 | 3.7 ±1.8 | |
| < 1 | 5 (2.0) | 12 (3.9) | 0.32 |
| 1 to <2 | 32 (12.7) | 41 (13.4) | |
| 2 to 5 | 142 (56.3) | 181 (59.2) | |
| > 5 | 73 (29.0) | 72 (23.5) | |
| Race/ethnicity | |||
| Hispanic | 94 (37.3) | 89 (29.1) | 0.01 |
| White, non-Hispanic | 93 (36.9) | 151 (49.3) | |
| Other, non-Hispanic | 65 (25.8) | 66 (21.6) | |
| Maternal age, years (mean ±SD) b | 29.8±6.2 | 30.5±5.8 | |
| <30 | 114 (45.2) | 138 (45.1) | 0.95 |
| ≥30 | 135 (53.6) | 165 (53.9) | |
| Unknown | 3 (1.2) | 3 (1.0) | |
| Breastfeeding | |||
| Yes | 235 (93.2) | 272 (88.9) | 0.07 |
| Noc | 17 (6.8) | 34 (11.1) | |
| None to <3 months | 84 (33.3) | 90 (29.4) | |
| 3 to <6 months | 43 (17.1) | 49 (16.0) | |
| 6 to <12 months | 64 (25.4) | 78 (25.5) | |
| 12 or more months | 61 (24.2) | 89 (29.1) | 0.16 |
| Annual household income | |||
| <$15,000 | 24 (9.5) | 16 (5.2) | 0.006 |
| $15,000 to $29,999 | 33 (13.1) | 27 (8.8) | |
| $30,000 to $44,999 | 41 (16.3) | 36 (11.8) | |
| $45,000 to $59,999 | 41 (16.3) | 39 (12.7) | |
| $60,000 to $74,999 | 18 (7.1) | 29 (9.5) | |
| >$75,000 | 95 (37.7) | 159 (52.0) | |
| Neighborhood type | |||
| Urban | 181 (71.8) | 225 (73.5) | 0.13 |
| Suburban | 36 (14.3) | 28 (9.1) | |
| Rural | 29 (11.5) | 44 (14.4) | |
| Unknown | 6 (2.4) | 9 (3.0) | |
| Residence build year | |||
| 1980 to present | 96 (38.1) | 123 (40.2) | 0.96 |
| 1950 to 1979 | 88 (34.9) | 109 (35.6) | |
| Before 1950 | 33 (13.1) | 44 (14.4) | |
| Unknown | 35 (13.9) | 30 (9.8) | |
| Household member occupation d | |||
| Farmer/farm or ranch worker | 11 (4.4) | 15 (4.9) | 0.76 |
| Gardener, groundskeeper, landscape, or nursery worker | 11 (4.4) | 14 (4.6) | 0.90 |
| Packer or agricultural worker | 7 (2.8) | 6 (2.0) | 0.52 |
| Pesticide handler or mixer | 4 (1.6) | 7 (2.3) | 0.76 |
| Season of dust collection | |||
| Winter | 62 (24.6) | 42 (13.7) | 0.001 |
| Spring | 54 (21.4) | 91 (29.7) | |
| Summer | 82 (32.6) | 85 (27.8) | |
| Fall | 54 (21.4) | 88 (28.8) | |
| Year of interview | |||
| 2001–2002 | 63 (25.0) | 62 (20.3) | 0.10 |
| 2003–2004 | 92 (36.5) | 94 (30.7) | |
| 2005–2006 | 67 (26.6) | 101 (33.0) | |
| 2007 | 30 (11.9) | 49 (16.0) | |
| Self-reported insecticide use | |||
| Household e | |||
| Ant/cockroach use | 169 (67.1) | 224 (73.2) | 0.10 |
| Carpenter ants/termites | 10 (4.0) | 22 (7.2) | 0.10 |
| Flying insectsf | 63 (25.0) | 93 (30.4) | 0.15 |
| Fleas/ticks in home | 23 (9.1) | 35 (11.4) | 0.37 |
| Fleas/ticks on pets | 56 (22.2) | 90 (29.4) | 0.05 |
| Indoor insects | 200 (79.4) | 260 (85.0) | 0.07 |
| Lawn/garden insects | 65 (25.8) | 98 (32.0) | 0.10 |
| Professional g | |||
| Professional indoor | 24 (9.5) | 41 (13.4) | 0.20 |
| Professional outdoor | 57 (22.6) | 76 (24.8) | 0.71 |
Participants are cases and controls from the CCLS that consented to the tier 2 visit, and had adequate dust samples for measurement of insecticide concentrations
n=3 mothers of cases and n=3 mothers of controls missing age
n=1 participant missing data on breastfeeding was categorized as “no”
n=1 participant missing data on occupations was categorized as “no”
n=7 (n=3 cases and n=4 controls) missing household insecticide use information
Flying insects defined as any product to treat bees, wasps, hornets, flies, or mosquitos
n=76 (n=39 cases and n=37 controls) missing professional insecticide use information
Chi-Square tests were used to examine differences in characteristics comparing cases to controls; unknown values for maternal age, neighborhood type, year the residence was built, and insecticide uses were excluded for testing differences between cases and controls