Table 3.
Association of livestock exposures and contacts in general practice adjusted for distance to general practice in 144,984 person years between 2006 and 2009
| All contacts | Contacts for respiratory symptoms | Contacts for respiratory diagnoses | Contacts for acute respiratory infections | |
|---|---|---|---|---|
| RR (95 % CI) | RR (95 % CI) | RR (95 % CI) | RR (95 % CI) | |
| Livestock exposures | ||||
| Distance weighted PM10 emission from farms within 500 ma | 0.96 (0.94-0.97) | 0.89 (0.84-0.94) | 0.93 (0.88-0.98) | 0.94 (0.89-1.00) |
| Distance to the nearest farma | 1.04 (1.03-1.05) | 1.09 (1.05-1.13) | 1.07 (1.04-1.10) | 1.07 (1.03-1.11) |
| One or more farms within 500 m (ref no farms) | 0.97 (0.95-0.99) | 0.92 (0.87-0.97) | 0.94 (0.90-0.98) | 0.95 (0.90-1.00) |
| Number of farms within 500 m | 0.99 (0.99-0.99) | 0.98 (0.96-0.99) | 0.99 (0.98-0.995) | 0.98 (0.95-1.00) |
| Presence of farm animals within 500 m | ||||
| Cattle (ref no cattle) | ||||
| 1-69 | 0.99 (0.97-1.02) | 1.00 (0.92-1.08) | 0.98 (0.92-1.05) | 0.98 (0.91-1.06) |
| 70-299 | 0.96 (0.94-0.99) | 0.99 (0.92-1.07) | 0.95 (0.90-1.02) | 0.96 (0.89-1.04) |
| 300-4,210 | 0.96 (0.94-0.98) | 0.95 (0.88-1.04) | 0.95 (0.89-1.02) | 0.95 (0.87-1.03) |
| Swine (ref no swine) | ||||
| 1-649 | 1.00 (0.97-1.03) | 0.86 (0.79-0.94) | 0.99 (0.92-1.06) | 1.01 (0.93-1.10) |
| 650-1,999 | 0.99 (0.96-1.01) | 0.93 (0.85-1.01) | 0.95 (0.89-1.02) | 0.99 (0.91-1.08) |
| 2,000-32,660 | 0.94 (0.91-0.96) | 0.83 (0.76-0.90) | 0.89 (0.83-0.96) | 0.89 (0.82-0.97) |
| Poultry (ref no poultry) | ||||
| 1-13,999 | 0.99 (0.97-1.02) | 0.91 (0.82-1.01) | 1.03 (0.95-1.13) | 1.00 (0.90-1.11) |
| 14,000-401,250 | 1.05 (1.02-1.08) | 1.08 (0.98-1.19) | 1.09 (1.00-1.18) | 1.17 (1.06-1.30) |
| Sheep (ref no sheep) | ||||
| 1-49 | 0.99 (0.96-1.02) | 1.02 (0.92-1.13) | 1.01 (0.93-1.10) | 0.98 (0.88-1.09) |
| 50-1400 | 1.00 (0.97-1.04) | 1.04 (0.93-1.17) | 1.03 (0.93-1.13) | 1.00 (0.89-1.12) |
| Minks (ref no minks) | 0.95 (0.91-0.99) | 0.93 (0.81-1.07) | 0.97 (0.87-1.09) | 0.94 (0.81-1.08) |
| Goats (ref no goats) | 0.96 (0.91-1.01) | 1.01 (0.86-1.19) | 0.90 (0.79-1.03) | 0.95 (0.80-1.12) |
RRs or betas and 95 % CI were adjusted for age, gender and number of chronic diseases. Bold type indicates statistical significance (p<0.05). Presence of farm animals within 500 m adjusted for the presence of other types of livestock. aRR or beta and 95 % CI for an IQR increase in log-transformed exposure. IQR for ln(PM10, g∙y-1∙m-2) = 10.31, IQR for ln(distance to the nearest farm, m) = 0.82, IQR for ln(distance to GP practice, m)=1.60, corresponding to a 30,000-fold increase (exp10.31), a 2.28-fold increase (exp0.82) and a 4.96-fold increase (exp1.60) for non-transformed values. Increased RRs for ‘distance to the nearest farm’ indicate that living further away from the nearest farm is associated with an increased odds of disease, i.e. an inverse association with farm exposure.