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Table 4 Regression coefficients of CAR models

From: Environmental and demographic risk factors for campylobacteriosis: do various geographical scales tell the same story?

  Geographical unit Maximal % of variation
  Smallest Municipality Census consolidated subdvision Agriculture CLSC Census division Watershed  
Variable (n=1119) (n=1063) (n=903) (n=319) (n=155) (n=97) (n=71)  
Intercept 34.32 (1.83)* 35.98 (2.11)* 35.12 (2.37)* 39.54 (2.80)* 36.38 (3.97)* 23.35 (8.79)* 16.33 (6.34)*  
Ruminant density per km2 (ref.=none)
>20 8.72 (2.04)* 7.17 (2.14)* 10.76 (2.57)* 4.47 (3.21) 4.75 (5.20) 17.37 (10.55) 16.00 (13.10) 50
≤20 5.44 (1.63)* 3.25 (1.76) 4.68 (2.21)* 3.21 (2.40) 2.96 (3.41) 15.05 (8.98) 8.88 (5.77) 16
Poultry density per km2 (ref.=none)
>250 3.44 (1.52)* 2.06 (1.53) 3.84 (1.50)* −1.32 (2.75) 1.24 (3.82) 4.17 (4.69) 19.02 (7.55)* 453
≤250 −0.28 (1.62) −1.05 (1.60) 1.68 (1.48) −4.62 (2.48) −1.15 (3.28) 1.36 (4.50) 18.38 (4.59)*  
Slaughterhouse (ref.=none)       
Large poultry 65.90 (6.75)* 59.24 (6.47)* 27.81 (5.91)* 24.68 (7.33)* 20.42 (5.91)* 15.99 (6.84)* 1.96 (7.14) 312
Others −1.18 (2.63) 0.94 (2.53) −1.40 (2.30) −2.51 (3.33) 1.72 (2.96) 1.52 (3.41) −5.74 (4.58)  
Diploma in % (ref.=50-75)       
<50 −3.80 (1.42)* −3.76 (1.41)* −4.25 (1.34)* −4.71 (3.09) −18.16 (6.49)* −19.68 (9.06)* −6.37 (4.38) 423
>75 −0.20 (1.54) −1.98 (1.64) −2.04 (1.78) −1.72 (2.50) −4.58 (2.56) −6.81 (4.13) 5.24 (6.00)  
Population density per km2 (ref.=6-400)
≤6 −2.25 (1.47) −2.48 (1.49) −1.28 (1.38) −6.78 (4.09) n/ab n/a 3.64 (5.66)  
>400 3.58 (1.50)* 4.59 (1.52)* 0.36 (1.53) 5.69 (2.16)* 0.91 (2.76) 2.93 (3.21) 0.68 (3.75) 59
Precipitation in mm (ref.=2.9-3.1)
<2.9 −3.91 (1.86)* −3.60 (2.40) −4.56 (2.07)* −9.59 (3.49)* −14.09 (4.52)* −15.96 (5.39)* −7.92 (4.51) 308
>3.1 1.33 (1.57) 1.09 (1.99) 1.19 (1.81) 3.18 (2.94) 8.89 (3.55)* 5.80 (4.31) 5.61 (5.35)  
Temperature in °C (ref.=3.1-6.9)
<3.1 1.08 (1.65) −3.45 (2.18) −1.55 (1.88) 1.67 (3.08) 3.14 (3.39) 7.03 (3.90) 10.25 (4.05)*  
>6.9 −9.50 (1.92)* −4.00 (2.57) −5.32 (2.61)* −10.42 (3.42)* −6.47 (3.87) −6.43 (5.06) −17.30 (8.73)* 225
Lambdac 0.58* 0.8* 0.68* 0.45* 0.59 0.56* 0.31*  
Model r2 0.21 0.27 0.26 0.24 0.48 0.37 0.52  
  1. Regression coefficients (standard errors) of conditional autoregressive models predicting the annual incidence of campylobacteriosis per 100,000 people in Quebec, Canada, 1996–2006.
  2. a Maximal percentage of variation in statistically significant estimates of regression coefficient based on different geographical units.
  3. b Not applicable (absence of areas with those values for the specific unit set).
  4. c Spatial error parameter adjusting for spatial correlation.
  5. *p<0.05.