Volume 11, Number 8—August 2005
Research
Sheep Feed and Scrapie, France
Sandrine Philippe*, Christian Ducrot†, Pascal Roy‡, Laurent Remontet‡, Nathalie Jarrige*, and Didier Calavas*
Table 2
Multivariate analysis of potential confounding factors
| Factors | Modalities* | No. controls (%) | No. cases (%) | Log-linear model |
|
|---|---|---|---|---|---|
| OR† | 95% CI | ||||
| Flock size | <133* | 100 (29) | 11 (12) | 1.0 | – |
| 133–236 | 87 (25) | 24 (25) | 2.5 | 1.1 – 5.5 | |
| 237–366 | 77 (22) | 33 (35) | 4.0 | 1.8 – 8.6 | |
| >366 | 86 (25) | 26 (28) | 3.0 | 1.3 – 7.0 | |
| Type of flock | Dairy* | 229 (65) | 64 (68) | 1.0 | – |
| Meat | 113 (32) | 27 (29) | 1.0 | 0.3 – 3.2 | |
| Mixed | 8 (2) | 3 (3) | 1.2 | 0.3 – 5.5 | |
| Intensification criteria | None* | 241 (69) | 56 (60) | 1.0 | – |
| Production monitoring | 38 (11) | 16 (17) | 1.8 | 0.8 – 3.8 | |
| Involvement in a breeding scheme | 71 (20) | 22 (23) | 1.1 | 0.6 – 2.1 | |
*Reference modality.
†OR, odds ratio; CI, confidence interval.
