Table 2.
ORs (95% CI) for paraquat exposure and Parkinson’s disease estimated with logistic regression, according to type of exposure assessment
| Exposure assessment and time window | Patients with PD | Controls | OR (95% CI) | P | Patients with PD | Controls | OR (95% CI) | P | |
|---|---|---|---|---|---|---|---|---|---|
|
|
|
||||||||
| n (%) or mean (SD) | n (%) or mean (SD) | ||||||||
|
| |||||||||
| Application near | Residence | Workplace | |||||||
| Any application, yes | |||||||||
| 1974–index year | 591 (71.7) | 577 (70.3) | 1.10 (0.88, 1.37) | 0.41 | 551 (68.9) | 500 (63.9) | 1.23 (0.99, 1.53) | 0.06 | |
| 20y–10y prior to index year | 423 (51.6) | 363 (44.4) | 1.40 (1.14, 1.72) | 0.001 | 382 (49.9) | 305 (42.8) | 1.38 (1.11, 1.72) | 0.004 | |
| 10 y prior to index year | 347 (42.3) | 290 (35.5) | 1.37 (1.11, 1.69) | 0.003 | 230 (34.2) | 201 (33.8) | 1.14 (0.89, 1.46) | 0.48 | |
| Duration of exposure, per one (equivalent to living near paraquat application within buffer every year in window) | |||||||||
| 1974–index year | 0.23 (0.28) | 0.19 (0.24) | 1.91 (1.30, 2.83) | 0.001 | 0.24 (0.29) | 0.18 (0.24) | 2.15 (1.46, 3.19) | 1.3E-04 | |
| 20y–10y prior to index year | 0.25 (0.33) | 0.19 (0.30) | 1.83 (1.32, 2.53) | 3.0E-04 | 0.25 (0.34) | 0.18 (0.29) | 2.15 (1.53, 3.06) | 1.5E-05 | |
| 10y prior to index year | 0.20 (0.31) | 0.15 (0.28) | 1.67 (1.18, 2.36) | 0.004 | 0.19 (0.33) | 0.14 (0.27) | 1.86 (1.27, 2.77) | 0.002 | |
| Average exposure, per 10 pounds paraquat active ingredient applied per acre per year within buffera | |||||||||
| 1974–index year | 1.02 (1.92) | 0.83 (1.72) | 1.72 (0.99, 3.04) | 0.06 | 1.25 (2.52) | 0.88 (2.01) | 2.08 (1.31, 3.38) | 0.002 | |
| 20y–10y prior to index year | 1.20 (2.70) | 0.90 (2.36) | 1.61 (1.07, 2.44) | 0.02 | 1.51 (3.52) | 0.90 (2.56) | 1.96 (1.54, 2.89) | 5.2E-04 | |
| 10y prior to index year | 1.20 (3.00) | 0.91 (2.55) | 1.35 (0.94, 1.97) | 0.11 | 1.61 (4.26) | 1.08 (3.64) | 1.49 (1.11, 2.05) | 0.01 | |
| Average exposure, log transformed, per oneb | |||||||||
| 1974–index year | 0.46 (0.62) | 0.39 (0.56) | 1.23 (1.04, 1.46) | 0.02 | 0.49 (0.69) | 0.37 (0.60) | 1.32 (1.12, 1.55) | 8.6E-04 | |
| 20y–10y prior to index year | 0.44 (0.71) | 0.35 (0.62) | 1.24 (1.07, 1.45) | 0.006 | 0.48 (0.78) | 0.32 (0.64) | 1.37 (1.18, 1.60) | 6.6E-05 | |
| 10y prior to index year | 0.40 (0.72) | 0.32 (0.65) | 1.19 (1.03, 1.38) | 0.02 | 0.42 (0.83) | 0.30 (0.69) | 1.27 (1.09, 1.49) | 0.003 | |
Models control for age, race/ethnicity, sex, index year and study wave.
PD, Parkinson’s disease; CI, confidence interval; OR, odds ratio; y, years.
a
After outlier removal, the pounds of paraquat applied per acre in any given year ranged from 0 to 41.47 (Figure 2).
b
Average exposure (year average paraquat applied per acre exposure assessment) was offset by 1 and log transformed. Values ranged from 0 to 3.4.