Table 2.
Ever use of specific pesticides and risk of specialist-confirmed RA among AHS applicators with ≥ 24 months continuous Medicare-FFS (1999–2016)
| Ever-used1 | Non-cases (N = 22,084) | Cases2 (N = 161) | Relative Risk (95% CI)3 |
|---|---|---|---|
| N (%) | N (%) | ||
| Insecticides | |||
| Organochlorines | |||
| Aldrin | 6502 (33) | 46 (33) | 1.07 (0.73–1.55) |
| Chlordane | 7065 (36) | 51 (36) | 0.93 (0.66–1.32) |
| DDT | 8906 (45) | 72 (51) | 1.05 (0.75–1.48) |
| Dieldrin | 2295 (12) | 14 (10) | 0.85 (0.48–1.49) |
| Heptachlor | 5178 (26) | 33 (24) | 0.98 (0.64–1.50) |
| Lindane | 4674 (24) | 33 (24) | 1.09 (0.73–1.62) |
| Toxaphene | 4169 (21) | 40 (29) | 1.31 (0.90–1.90) |
| Organophosphates | |||
| Chlorpyrifos | 8203 (41) | 57 (40) | 1.05 (0.75–1.48) |
| Diazinon | 7059 (36) | 53 (38) | 0.99 (0.70–1.41) |
| Dichlorvos | 2064 (11) | 14 (10) | 1.16 (0.66–2.04) |
| Fonofos | 4328 (22) | 31 (23) | 1.37 (0.89–2.12) |
| Malathion | 14,493 (73) | 115 (82) | 1.77 (1.14–2.73) |
| Parathion | 3681 (19) | 37 (26) | 1.32 (0.90–1.94) |
| Phorate | 7447 (38) | 55 (39) | 1.40 (0.96–2.04) |
| Terbufos | 7122 (37) | 50 (37) | 1.25 (0.87–1.81) |
| Carbamates | |||
| Aldicarb | 2000 (10) | 18 (13) | 0.82 (0.47–1.45) |
| Carbaryl | 12,247 (62) | 106 (75) | 1.65 (1.10–2.46) |
| Carbofuran | 5917 (30) | 49 (37) | 1.41 (0.99–2.01) |
| Pyrethroids | |||
| Permethrin - crops | 2184 (11) | 17 (13) | 1.18 (0.71–1.96) |
| Permethrin - animals | 1950 (10) | 12 (9) | 1.11 (0.61–2.03) |
| Herbicides | |||
| Anilids/anilines | |||
| Alachlor | 10,517 (54) | 81 (59) | 1.40 (0.99–1.98) |
| Metolachlor | 8647 (44) | 70 (51) | 1.57 (1.11–2.23) |
| Pendimethalin | 8606 (44) | 58 (41) | 0.97 (0.69–1.36) |
| Trifluralin | 10,103 (52) | 70 (52) | 1.29 (0.89–1.86) |
| Phenoxy | |||
| 2,4-D | 15,885 (79) | 109 (77) | 1.08 (0.72–1.63) |
| 2,4,5-T | 6317 (32) | 38 (27) | 0.80 (0.54–1.17) |
| 2,4,5-TP | 2504 (13) | 13 (9) | 0.70 (0.40–1.25) |
| Thiocarbamate | |||
| Butylate | 6456 (34) | 49 (36) | 1.17 (0.79–1.74) |
| EPTC | 3288 (17) | 27 (20) | 1.57 (1.00-2.44) |
| Triazine/Triazinone | |||
| Atrazine | 14,409 (74) | 107 (78) | 1.36 (0.88–2.12) |
| Cyanazine | 7912 (41) | 53 (38) | 1.24 (0.84–1.82) |
| Metribuzin | 8963 (46) | 66 (47) | 1.45 (1.01–2.08) |
| Other | |||
| Chlorimuron Ethyl | 6623 (34) | 48 (34) | 1.16 (0.82–1.66) |
| Dicamba | 9581 (49) | 60 (43) | 1.12 (0.74–1.68) |
| Glyphosate | 15,985 (80) | 113 (80) | 0.99 (0.65–1.50) |
| Imazethapyr | 7492 (39) | 44 (32) | 1.07 (0.69–1.65) |
| Paraquat | 4661 (24) | 41 (29) | 1.12 (0.77–1.65) |
| Petroleum Oil | 8918 (46) | 65 (46) | 1.22 (0.86–1.72) |
| Fungicides/Fumigants | |||
| Benomyl | 2294 (12) | 28 (20) | 1.56 (0.99–2.44) |
| Captan | 2054 (11) | 16 (12) | 1.15 (0.68–1.94) |
| Chlorothalonil | 1583 (8) | 20 (14) | 1.32 (0.74–2.34) |
| Carbon tetrachloride/disulfide | 1741 (9) | 12 (9) | 0.98 (0.54–1.78) |
| Maneb | 2226 (11) | 20 (14) | 0.98 (0.59–1.62) |
| Metalaxyl | 4547 (23) | 44 (32) | 1.25 (0.84–1.85) |
| Methyl bromide | 3233 (16) | 31 (22) | 1.05 (0.67–1.65) |
1Lifetime history ever used specific pesticides at enrollment (1993–1997) or first follow-up (1999–2003) prior to rheumatoid arthritis (RA) diagnosis.
2Among participants with ≥ 24 months continuous fee for service (FFS) coverage (Parts A and B without Part C), including an initial ≥ 12-month clean period with no claims for RA, specialist-confirmed cases had ≥ 2 claims for RA ≥ 30 days apart plus ≥ 1 claim from a rheumatologist.
3Relative Risk and 95% confidence intervals (CI) calculated using log binomial regression in covariate-adjusted models. Models adjust for categorical age at enrollment (40–49, 50–59, 60–69, 70+), state (NC, IA), education (≤ high school, > high school) and smoking pack-years, and correlated pesticides: aldicarb (chlorothalonil and benomyl), chlorothalonil (aldicarb and benomyl), atrazine (alachlor), butylate (cyanazine and metribuzin).