Table 5.
Risk of RA in relation to combined atrazine with alachlor and/or metolachlor use.
| Ever used1: | Non-cases2 | Specialist-confirmed cases2 | Relative Risk1 |
|---|---|---|---|
| (N = 22,320) | (N = 161) | (95% CI) | |
| N (%) | N (%) | ||
| Atrazine + alachlor and/or metolachlor | |||
| None of these | 3552 (18) | 21 (15) | Reference |
| Alachlor and/or metolachlor, not atrazine | 1534 (8) | < 11 (*) | 1.39 (0.65–2.96) |
| Atrazine, not metolachlor or alachlor | 3056 (16) | 20 (15) | 1.29 (0.70–2.39) |
| Atrazine, and alachlor and/or metolachlor | 11,269 (58) | 88 (63) | 1.84 (1.11–3.04) |
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 coverage without Part C), including an initial ≥ 12-month clean period with no claims for rheumatoid arthritis; specialist-confirmed cases had ≥ 2 claims for RA ≥ 30 days apart plus claims from a rheumatologist. Asterix (*) indicates percent not shown if number or percent not shown due to < 11 in a cell or ability to infer the count of groups with < 11 exposed cases in conjunction with other data presented.
3Relative Risk estimates calculated using log binomial regression, adjusted for categorical age (40–49, 50–59, 60–69, 70+), state (NC, IA), education (≤ high school, > high school), and smoking pack year.