CRP and abscess: The patient demographics and clinical characteristics, including age, sex, size of the abscess, WBC, CRP, cause, Charlson comorbidity index, underlying disease, pre-procedure empyema, pulmonary embolism, drainage tube size, the distance of trans-aerated lung parenchyma, drainage tube indwelling time, culture positivity, the rationale of antibiotics use, were similar between the two groups.