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Table 5 Fixed effects in the final optimized generalized linear mixed models to determine potential risk factors for T. gondii-seropositivity in wild felids in human care. Modeling was performed assuming random effects by the variable “Zoo”

From: Toxoplasma gondii in small exotic felids from zoos in Europe and the Middle East: serological prevalence and risk factors

Model (AIC, model fit) Category Variable Odds ratio (95% confidence interval) z value P-value
15 (276.8)   (Intercept) 16.82 (2.36–120) 2.818 0.005**
  Individual Age 1.232 (1.13–1.34) 4.725 < 0.001***
  Food-related Cattle: fresh (ref.)    
   Cattle: fresh/frozen 0.507 (0.14–1.85) − 1.028 0.304
   Cattle: frozen 0.143 (0.04–0.57) − 2.756 0.006**
   Cattle: no 0.397 (0.12–1.37) − 1.462 0.144
  Housing Outdoor housing fenced in on all sides: no (ref.)    
   Outdoor housing fenced in on all sides: yes 0.261 (0.08–0.88) − 2.166 0.030*
  Housing Mesh size more > 5 cm (ref.)    
   Mesh size < 2 cm 0.547 (0.14–2.20) − 0.849 0.396
   Mesh size 2–5 cm 0.317 (0.10–0.99) − 1.982 0.047*
  Hygiene Wearing gloves: no (ref.)    
   Wearing gloves: yes 0.419 (0.20–0.90) − 2.239 0.025*
  1. Notes: Optimization of modeling was started with a full model [including all variables with a statistically significant effect (P < 0.1) in an initial bivariable generalized linear mixed model always including “Age” (years) in addition to the variable in question and proven independent by factor analysis] (Table 4). The Akaike information criterion (AIC) was used to characterize relative model quality. The full model had an AIC of 283.2. Optimization of the full model was done by a stepwise elimination of those variables that, if removed, did not cause an increase of AIC
  2. Abbreviations: ref., reference
  3. P ≤ 0.05, ** P ≤ 0.01, *** P < 0.001