TABLE 7.
Factors associated (P ≤ 0.05) with survival on multivariate analysis
| Factor | Category | No. of cases | SPSS results
|
LogXact results
|
||||
|---|---|---|---|---|---|---|---|---|
| Adjusted odds ratio | 95% confidence interval | P value | Adjusted odds ratio | 95% confidence interval | P value | |||
| Farm | Farm O | 17/20 (85%) | 0.23 | 0.02, 3.06 | 0.0006 | 0.26 | 0.004, 4.15 | 0.0012 |
| Farm Wa | 29/30 (97%) | 1 | 1 | |||||
| Farm M | 63/63 (100%) | 15,700 | <10−6, >106 | 3.97 | 0.1, infinity | |||
| Other | 60/74 (81%) | 0.31 | 0.03, 3.13 | 0.33 | 0.006, 3.35 | |||
| Strain | Aa | 31/32 (97%) | 1 | 0.048 | 1 | 0.083 | ||
| B | 12/12 (100%) | 1,840 | <10−6, >106 | 0.15 | 0.004, infinity | |||
| C | 22/22 (100%) | 6,150 | <10−6, >106 | 0.78 | 0.02, infinity | |||
| D | 13/16 (81%) | 0.11 | 0.006, 2.03 | 0.15 | 0.002, 3.71 | |||
| E | 18/22 (81%) | 0.08 | 0.005, 1.15 | 0.11 | 0.001, 1.84 | |||
| Other | 73/83 (88%) | 0.49 | 0.05, 4.57 | 0.50 | 0.01, 4.63 | |||
| Date of isolation | Sept./Oct. | 40/40 (100%) | 31,600 | <10−6, >106 | 0.005 | 8.11 | 1.07, infinity | 0.013 |
| Novembera | 62/68 (91%) | 1 | 1 | |||||
| December | 56/62 (90%) | 0.93 | 0.23, 3.8 | 0.94 | 0.19, 4.54 | |||
| Jan./Feb. | 11/17 (65%) | 0.45 | 0.09, 2.19 | 0.48 | 0.08, 2.84 | |||
a
This category was the reference category.