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Table 5 Logistic regression model for clinical variables related to killing or spontaneously death of newborn piglets dying until day 5 of age

From: Killing underweighted low viable newborn piglets: Which health parameters are appropriate to make a decision?

Risk categories Alive Dead Univariable model Multivariable model
n % n % OR 95%-CI p OR 95%-CI pb
Low Up    Low Up  
Total 372 71.68 147 28.32 x x x x x x x x
Herd/group (p = 0.0033) a
 11(ref) 26 56.52 20 43.48 1 x x x 1 x x x
 12 27 65.85 14 34.15 0.674 0.282 1.609 0.3741 0.229 0.053 0.984 0.4722
 13 19 51.35 18 48.65 1.232 0.516 2.937 0.6386 0.618 0.145 2.636 0.2897
 21 33 73.33 12 26.67 0.473 0.196 1.141 0.0956 0.281 0.074 1.071 0.7145
 22 25 60.98 16 39.02 0.832 0.353 1.959 0.6738 0.845 0.239 2.989 0.0373
 23 38 74.51 13 25.49 0.445 0.189 1.049 0.0643 0.326 0.086 1.232 0.9287
 31 26 83.87 5 16.13 0.250 0.082 0.767 0.0153 0.083 0.014 0.479 0.0451
 32 35 87.50 5 12.50 0.186 0.062 0.560 0.0028 0.212 0.048 0.933 0.4034
 33 38 95.00 2 5.00 0.068 0.015 0.318 0.0006 0.102 0.017 0.627 0.1074
 41 43 82.69 9 17.31 0.272 0.108 0.686 0.0058 0.195 0.055 0.687 0.2282
 42 28 66.67 14 33.33 0.650 0.273 1.547 0.3301 1.523 0.430 5.394 0.0005
 43 34 64.15 19 35.85 0.726 0.323 1.632 0.4390 0.401 0.117 1.369 0.6833
Body weight (p = 0.0418) a
  ≤ 0.86 kg 69 41.07 99 58.93 23.475 11.870 46.424  < .0001 3.715 1.103 12.507 0.1221
 0.86–1 kg 123 76.88 37 23.13 4.922 2.417 10.023  < .0001 2.973 1.238 7.140 0.1885
  > 1 kg (ref) 180 94.24 11 5.76 1 x x x 1 x x x
Vitality score (p ≤ .0001) a
 0 (ref) 296 90.80 30 9.20 1 x x x 1 x x x
 1 74 54.41 62 45.59 8.265 4.989 13.694  < .0001 3.325 1.589 6.958 0.0710
 2 2 3.51 55 96.49 271.333 63.013 1168.351  < .0001 61.358 10.609 354.867  < .0001
Intrauterine growth retardation score (p = 0.1765) a
 0 (ref) 274 88.10 37 11.90 1 x x x 1 x x x
 1 86 63.24 50 36.76 4.305 2.640 7.022  < .0001 1.582 0.656 3.814 0.6534
 2 12 16.67 60 83.33 37.027 18.231 75.201  < .0001 3.412 0.929 12.538 0.0678
Rectal temperature (p = 0.0003) a
  ≤ 37.5 °C 48 32.21 101 67.79 14.818 9.336 23.519  < .0001 3.372 1.745 6.517 0.0003
  > 37.5 °C (ref) 324 87.57 46 12.43 1 x x x 1 x x x
Sex (p = 0.0680)a
 Female (ref) 187 73.91 66 26.09 1 x x x 1 x x  
 Male 185 69.55 81 30.45 1.241 0.846 1.820 0.2704 1.712 0.961 3.049 0.0680
  1. Due to missing values vitality scores 2 and 3 were aggregated to one category for modelling purposes
  2. ref, reference category; OR, odds ratio estimate; CI, confidence limits; p, level attained for the statistical test associated
  3. aGeneral p value Wald’s Chi2-test (p < 0.05 are marked in bold)
  4. bp value Wald’s Chi2-test (p < 0.05 are marked in bold) to the reference category