TABLE II.
Associations between early-life farm exposures and current asthma in the ALHS
| Early-life exposures* |
Cases n (%) |
Noncases n (%) |
Crude OR (95% CI) |
Adjusted OR (95% CI)† |
|---|---|---|---|---|
| Total | 1198 | 2031 | ||
| Mother lived on farm while pregnant | ||||
| No | 328 (27.4) | 476 (23.4) | Ref | Ref |
| Yes | 851 (71.0) | 1534 (75.5) | 0.81 (0.68–0.95) | 0.88 (0.74–1.05) |
| Missing | 19 (1.6) | 21 (1.0) | ||
| Mother performed farm activities while pregnant | ||||
| No | 374 (31.2) | 604 (29.7) | Ref | Ref |
| Yes | 755 (63.0) | 1332 (65.6) | 0.92 (0.78–1.07) | 1.02 (0.87–1.21) |
| Missing | 69 (5.8) | 95 (4.7) | ||
| Mother worked with farm animals while pregnant | ||||
| No | 371 (31.0) | 624 (30.7) | Ref | Ref |
| Yes | 722 (60.3) | 1257 (61.9) | 0.97 (0.83–1.13) | 1.10 (0.93–1.30) |
| Missing | 105 (8.8) | 150 (7.4) | ||
| Family lived on farm when born | ||||
| No | 327 (27.3) | 472 (23.2) | Ref | Ref |
| Yes | 856 (71.5) | 1537 (75.7) | 0.80 (0.68–0.95) | 0.89 (0.74–1.06) |
| Missing | 15 (1.3) | 22 (1.1) | ||
| Farm animal exposure before age 3 | ||||
| No | 316 (26.4) | 540 (26.6) | Ref | Ref |
| Yes | 762 (63.6) | 1313 (64.6) | 0.99 (0.84–1.17) | 1.11 (0.93–1.32) |
| Missing | 120 (10.0) | 178 (8.8) | ||
| Farm animal exposure before age 6 | ||||
| No | 238 (19.9) | 409 (20.1) | Ref | Ref |
| Yes | 913 (76.2) | 1538 (75.7) | 1.02 (0.85–1.22) | 1.18 (0.97–1.42) |
| Missing | 47 (3.9) | 84 (4.1) | ||
| Breast-fed | ||||
| No | 411 (34.3) | 684 (33.7) | Ref | Ref |
| Yes | 568 (47.4) | 961 (47.3) | 0.98 (0.84–1.16) | 1.14 (0.95–1.35) |
| Missing | 219 (18.3) | 386 (19.0) | ||
| Raw milk | ||||
| No | 239 (19.9) | 422 (20.8) | Ref | Ref |
| Yes | 889 (74.2) | 1498 (73.8) | 1.05 (0.88–1.25) | 1.23 (1.01–1.49) |
| Missing | 70 (5.8) | 111 (5.5) | ||
| Indoor furry pets before age 6 | ||||
| No | 839 (70.0) | 1480 (72.9) | Ref | Ref |
| Yes | 340 (28.4) | 507 (25.0) | 1.18 (1.01–1.39) | 1.14 (0.97–1.35) |
| Missing | 19 (1.6) | 44 (2.2) | ||
| Mother smoked cigarettes when pregnant | ||||
| No | 1022 (85.3) | 1764 (86.9) | Ref | Ref |
| Yes | 117 (9.8) | 169 (8.3) | 1.20 (0.93–1.53) | 1.14 (0.88–1.47) |
| Missing | 59 (4.9) | 98 (4.8) | ||
| Parents smoked cigarettes in house before age 6 | ||||
| No | 503 (42.0) | 936 (46.1) | Ref | Ref |
| Yes | 655 (54.7) | 1043 (51.4) | 1.17 (1.01–1.35) | 1.17 (1.01–1.36) |
| Missing | 40 (3.3) | 52 (2.6) | ||
*
Exposures are modeled individually, one at a time.
†
Logistic regression used to estimate ORs adjusted for age, sex, race, state, and pack years.