TABLE 5

Adjusted risk factors for mortality among patients with proven and probable chronic Q fever

Multivariable model with risk factors includedaAll-cause mortality (HR [95% CI])bMortality definitely or probably due to chronic Q fever (HR [95% CI])
Model 1
    Age in 10 yr (continuous)1.57 (1.13–2.19)1.68 (1.09–2.59)
    Proven chronic Q fever1.63 (0.62–4.26)5.65 (0.71–44.82)
    Vascular infection1.48 (0.73–2.99)1.81(0.71–4.59)
    Acute presentation with chronic Q fever1.96 (1.02–3.78)2.75 (1.27–5.95)
Model 2
    Age in 10 yr (continuous)1.59 (1.14–2.21)1.71 (1.11–2.62)
    Proven Q fever1.84 (0.71–4.76)6.66 (0.84–52.59)
    Vascular infection1.34 (0.63–2.85)1.46 (0.53–3.99)
    Surgical treatment of chronic Q fever1.51 (0.75–3.04)2.09 (0.89–4.89)
  • a Two multivariable models were constructed because of multicollinearity between acute presentation with chronic Q fever and surgical treatment of chronic Q fever. Model 1 includes acute presentation with chronic Q fever and model 2 surgical treatment of chronic Q fever.

  • b HR, hazard ratio; 95% CI, 95% confidence interval.