Table 6.
Final multivariable models determined for aEPEC and EHEC shedding, using ‘dairy herd’ as a clustering constraint
| Parameter | Comparison | OR* | 95% CI | P value | QIC | QICu | |
|---|---|---|---|---|---|---|---|
| Final models aEPEC | |||||||
| 1 | Any disease or treatment | Any vs. none† | 0·55 | 0·33–0·90 | 0·018 | 297·9 | 299·9 |
| 2 | Average weekly humidity (%) | Each unit increase | 1·067 | 1·034–1·10 | <0·0001 | 290·3 | 294·6 |
| Faecal score | (1, 2) vs. 3† | 0·45 | 0·21–0·95 | 0·037 | |||
| (4, 5) vs. 3† | 0·94 | 0·28–3·19 | 0·92 | ||||
| Final models EHEC | |||||||
| 1 | Hygiene score | >2 vs. (1, 2) † | 0·4 | 0·25–0·65 | 0·0002 | 237·9 | 235·3 |
| Cow contact | Each unit increase | 0·97 | 0·96–0·99 | 0·0002 | |||
| Antibiotic or other treatment | Ever antibiotic vs. none listed† | 1·32 | 1·017–1·72 | 0·0373 | |||
| Ever other vs. none listed† | 0·49 | 0·17–1·44 | 0·196 | ||||
| 2 | Average weekly temperature (°F) | Each unit increase | 1·06 | 1·02–1·10 | 0·003 | 238·9 | 229·9 |
| Days in milk | Each day increase | 0·88 | 0·79–0·99 | 0·028 | |||
aEPEC, Atypical enteropathogenic E. coli; EHEC, Enterohaemorrhagic E. coli; OR, Odds ratio; CI, confidence interval; QIC, quasi-likelihood independent model criterion.
* Comparison odds of shedding.
†
Reference category.