Skip to main content

Table 1 Descriptive statistics of major demographic variables of observed and the matched dataset

From: Spread of porcine circovirus associated disease (PCVAD) in Ontario (Canada) swine herds: Part II. Matched case-control study

  Control times Case times
Variable Mean Median sd* iqr* N* Mean Median sd* iqr* N*
Herd PRRSv status (proportion positive) 0.86 1.00 0.35 0.00 510 0.91 1.00 0.29 0.00 170
Cumulative local exposure (proportion) 0.16   0.37   510 0.17   0.38   170
Number of high-risk exposures 0.04 0.00 0.20 0.00 510 0.08 0.00 0.30 0.00 170
High-risk local exposure (proportion) 0.04   0.19   510 0.08   0.27   170
Number of nursery contacts/month 1.09 0.00 2.41 0.50 510 0.75 0.00 2.09 0.00 170
Number of feed contacts/month 4.06 4.00 2.53 2.33 510 4.59 4.00 3.73 4.00 170
Number of direct contactsa/month 1.39 0.00 2.46 2.00 510 1.13 0.00 2.20 1.17 170
Number of indirect contactsb/month 6.61 5.67 4.25 3.67 510 7.01 6.00 4.08 4.00 170
Total capacity for growing animals 2161.33 2000.00 1586.11 1525.00 510 2180.14 2000.00 1461.31 1520.00 170
Easting (100 kms) 4.87 4.87 0.57 0.65 510 5.05 5.01 0.71 0.50 170
Number of sows 321.60 240.00 281.66 280.00 279 357.13 240.00 398.05 290.00 92
Number of nursery pigs 1363.81 1000.00 1170.90 1600.00 396 1355.88 900.00 1400.92 1600.00 116
Number of finisher pigs 1308.81 1100.00 1083.18 361.00 510 1421.15 1250.00 982.14 1350.00 127
Number of breeding contacts/month 5.11 4.08 4.27 6.92 278 5.57 4.67 4.36 7.38 92
Herd type: farrow-to-finish 43.14     220 41.18     70
Herd type: farrow-to-grow 11.37     58 12.94     22
Herd type: finisher 21.76     111 30.00     51
Herd type: nursery 17.84     91 12.35     21
Herd type: nursery and finisher 5.88     30 3.53     6
High risk exposure: not present 96.27     491 92.35     157
High risk exposure: within ownership 0.00     0 2.94     5
High risk exposure: outside ownership 3.73     19 4.71     8
  1. *sd = standard deviation, iqr = interquartile range, N = number of observations
  2. a frequency of monthly contacts through incoming movement of nursery and finisher pigs
  3. b frequency of monthly contacts through incoming visits of service vehicles without pigs (feed deliveries, veterinarians, veterinary suppliers, other service personnel)
\