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Table 3 The output (parameter estimates, standard errors and p-values) of the mixed effect logistic regression (see Table  1 for definitions)

From: Climate and environmental change drives Ixodes ricinus geographical expansion at the northern range margin

Variable

Estimate

Std. error

Exp(est)

P-value

Δ AIC

Intercept

2.30

0.84

 

0.006

 

Area shrubi 1 vs. 0*

1.05

0.27

2.86

<0.001

14

Area shrubi 2 vs. 0*

0.85

0.23

2.35

<0.001

Area shrubi 3 vs. 0*

0.79

0.23

2.21

<0.001

Meanarea_ p

0.45

0.12

1.40

<0.001

9

Meanarea _p2

−0.11

0.03

<0.001

RHmean Oct-Mar

1.21

0.13

3.34

<0.001

88

BlackFrdays

0.92

0.16

2.50

<0.001

55

SnoStartDays

1.17

0.20

3.23

<0.001

34

NuFarms

2.67

0.31

2.27

<0.001

94

NuFarms2

−1.85

0.21

<0.001

Red deer

1.28

0.22

3.59

<0.001

29

Pasture

−1.36

0.30

0.25

<0.001

18

RRSum May

−0.18

0.15

0.59

0.224

46

RRSu m May 2

−0.35

0.06

<0.001

RRSum Mar

−0.40

0.14

0.67

0.004

6

TIncr + 5 < Days Jun

−1.11

0.21

0.40

<0.001

27

TIncr + 5 < Day s Jun 2

0.19

0.04

<0.001

TMeanSD Apr

0.43

0.22

1.93

0.047

5

TMeanS D Apr 2

0.22

0.08

0.004

TDecr ÷ 5 < DaysJan − Dec

0.22

0.10

1.25

0.035

2

  1. Δ AIC denotes the change in AIC level obtained if excluding the relevant variable from the selected model. The continuous variables are scaled (before taking polynomials) to mean zero and variance one. The factor by which the odds of positive outcome are increased for each one-unit change in the variables are represented by the computed exp (estimates). For the polynomials the odds ratio is calculated only for an increase of one standard deviation from mean. ICC (Intraclass correlation; ratio of the variance between subjects over the total variance) for municipality was 0.33 and ICC for timespan was 0.36. The “Area shrubi” variable was categorized (in 4 equal parts defined by quartiles) to capture the nonlinear relationship (at logit-scale) with the outcome. The variables Area shrubi, BlackFrDays and RRSumMar represent the rough grazing level.