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Table 1 Results of the space-time scan statistic using “parasitic liver” condemnation data

From: Comparison of covariate adjustment methods using space-time scan statistics for food animal syndromic surveillance

Date of cluster No. of abattoirs in cluster Latitude (°N) Longitude (°W) Radius (Km) No. of cases Relative risk1 P-value
a) Unadjusted Poisson space-time scan test
Jul 2004 - Dec 2007 16 44.52 80.92 62.45 12907 3.66 < 0.001
Mar 2002 - Aug 2005 26 43.60 79.81 62.52 6385 0.36 < 0.001
b) Animal-adjusted Poisson space-time scan test
Dec 2006 - Dec 2007 14 44.53 80.99 52.98 4973 3.90 < 0.001
Dec 2001 - May 2005 51 42.91 79.50 117.97 8732 0.45 < 0.001
Aug 2003 - Jan 2007 69 44.36 76.35 255.37 13849 1.59 < 0.001
c) Model-adjusted space-time scan test
Mar 2001 - Jun 2002 1 43.90 81.31 0 420 4.91 < 0.001
Sep 2003 - May 2004 71 43.18 80.51 98.22 4576 1.52 < 0.001
Sep 2001 - Dec 2001 16 43.33 79.98 46.01 1335 2.19 < 0.001
Mar 2004 - Nov 2006 2 44.11 80.80 0 2338 0.62 < 0.001
Jan 2001 - Mar 2001 72 44.40 77.61 197.95 496 0.49 < 0.001
Mar 2005 - Jan 2006 1 44.36 76.35 0 56 0.18 < 0.001
d) Space-time permutation scan test
Jan 2001 - Sep 2002 2 43.65 79.86 4 2335 6.76 < 0.001
Jan 2001 - Sep 2003 7 44.13 80.61 29.42 341 0.11 < 0.001
Sec 2006 - Dec 2007 2 44.11 80.80 0 4431 3.06 < 0.001
e) Space-time scan test of residuals
No statistically significant clusters found
  1. 1The values in this column for the space-time permutation model refer to the observed/expected value.