Table 1.
Characteristics of participants at enrollment in the Agricultural Health Study (n=20,409), Iowa and North Carolina
| Characteristics | No OI, n (%) (n=18340) |
OI, n (%) (n=2069) |
|---|---|---|
| Age (years)a | ||
| ≤45 | 9220 (50.3) | 812 (39.2) |
| >45-55 | 5098 (27.8) | 584 (28.2) |
| >55-65 | 3332 (18.2) | 520 (25.1) |
| >65 | 690 (3.8) | 153 (7.4) |
| Sex | ||
| Female | 528 (2.9) | 48 (2.3) |
| Male | 17812 (97.1) | 2021 (97.7) |
| Raceb | ||
| Other | 291 (1.6) | 25 (1.2) |
| White | 18033 (98.4) | 2042 (98.8) |
| Statea | ||
| Iowa | 12765 (69.6) | 1500 (72.5) |
| North Carolina | 5575 (30.4) | 569 (27.5) |
| Marital statusa,c | ||
| Never married | 1636 (8.9) | 129 (6.2) |
| Married/Living as married | 15911 (86.9) | 1845 (89.3) |
| Divorced/Widowed | 773 (4.2) | 93 (4.5) |
| Education | ||
| ≤ High school | 9591 (52.3) | 1057 (51.1) |
| 1-3 year beyond high school | 4820 (26.3) | 584 (28.2) |
| ≥ College graduate | 3929 (21.4) | 428 (20.7) |
| Smoking statusa | ||
| Never | 10496 (57.2) | 1037 (50.1) |
| Former | 5666 (30.9) | 726 (35.1) |
| Current | 2178 (11.9) | 306 (14.8) |
| Chewing tobacco use | ||
| No | 15825 (86.3) | 1790 (86.5) |
| Yes | 2515 (13.7) | 279 (13.5) |
| Snuff use | ||
| No | 17534 (95.6) | 1977 (95.6) |
| Yes | 806 (4.4) | 92 (4.4) |
| Alcohol intake (past 12 months)d | ||
| No | 5720 (32.1) | 619 (30.9) |
| Yes | 12081 (67.9) | 1386 (69.1) |
| Ever diagnosed with head injurya,e,f | ||
| No | 9114 (87.3) | 1048 (83.6) |
| Yes | 1325 (12.7) | 205 (16.4) |
| Repair enginesa | ||
| No | 10264 (56) | 1103 (53.3) |
| Yes | 8076 (44) | 966 (46.7) |
| Replace asbestos brake liningsa | ||
| No | 15402 (84) | 1676 (81) |
| Yes | 2938 (16) | 393 (19) |
| Handle stored grain | ||
| No | 4823 (26.3) | 524 (25.3) |
| Yes | 13517 (73.7) | 1545 (74.7) |
| Work in swine confinement areas | ||
| No | 12736 (69.4) | 1431 (69.2) |
| Yes | 5604 (30.6) | 638 (30.8) |
| Weld | ||
| No | 5144 (28) | 539 (26.1) |
| Yes | 13196 (72) | 1530 (73.9) |
| Paint | ||
| No | 5144 (28) | 569 (27.5) |
| Yes | 13196 (72) | 1500 (72.5) |
| Parkinson’s diseasea,g,h | ||
| No | 18237 (99.6) | 1947 (94.8) |
| Yes | 70 (0.4) | 106 (5.2) |
Abbreviations: OI, Olfactory impairment
a
p-value from Chi-square tests ≤ 0.05
b
Race missing: n=18
c
Marital status missing n=22
d
Alcohol intake missing: n=603
e
Head injury missing: n=8717
f
Information on these variables was asked only in the take-home survey (completed by 44% of the enrollees)
g
Parkinson’s disease missing n=49
h
All characteristics except for Parkinson’s disease were asked at enrollment; self-reported Parkinson’s disease at enrollment or at any follow-up to the third.