Table 1 Baseline characteristics of the study population
Baseline characteristics and comorbiditiesStudy populationCPE/EmpUncomplicated pneumoniap Value
Age (years)66 (51–78)57 (41–68)67 (51–78)<0.0001
Gender (% male)49.2%57.6%48.5%0.1
Chronic cardiac disease19.1%9.8%19.8%0.02
Liver disease5%10.9%4.6%0.009
Neurological disease11.1%2.2%11.8%0.01
Chronic renal failure6%6.5%5.9%0.8
Diabetes mellitus10.2%6.5%10.5%0.2
Chronic alcohol abuse5.5%13%4.9%0.002
Intravenous drug use3%10.9%2.4%<0.0001
Current smokers34.2%44.6%33.4%0.04
  • The p value is derived from comparison between patients with CPE/Emp and patients with uncomplicated pneumonia using the χ2 test, except for age (Mann–Whitney U test).

  • COPD, chronic obstructive pulmonary disease; CPE/Emp, complicated parapneumonic effusion or empyema.