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. 2012 Oct 5;7(10):e46310. doi: 10.1371/journal.pone.0046310

Table 4. Resource hypothesis model formulation and coefficient estimates for cross sectional prevalence study design.

Model Parameter Coefficient estimate Standard error Z value P value Odds ratio
log [π÷(1−π)] = β12CS+β3DS+β4 |ΔEVI|+β5HS+β6NWB+β7DW+β8DP+β9X+β10Y+r.eff.(location) Calibration: le Cessie-van Houwelingen goodness of fit test (Z = 0.2, P = 0.8) Validation: AUC 0.7 Pseudo r2 = 14% (Intercept) 12.04 143.76 0.08 0.93
Condition score (CS) 0.76 0.39 1.93 0.05 2.13
Dist. to streams (DS) −0.57 0.21 −2.73 0.01 0.57
EVI decline (ΔEVI) −0.38 0.15 −2.59 0.01 0.68 *
Herd size (HS) 0.01 0.02 0.61 0.54 1.01
No. water bodies (NWB) 0.06 0.05 1.26 0.21 1.06
Wallaby herd density (DW) 0.38 0.38 1.00 0.32 1.46*
Wild pig density (DP) −0.84 0.40 −2.09 0.04 0.43 *
X coordinate (X) −0.34 0.90 −0.38 0.71 0.71
Y coordinate (Y) −1.60 2.29 −0.70 0.49 0.20

Random effects terms for herd, and fixed effect covariates for latitude and longitude were included to control clustering of data and spatial trends or autocorrelation.

*

These covariates were transformed (normalised z = (x−μ)÷σ) to yield more interpretable odds ratios.