Table 1. Demographic characteristics of 208 patients with PPE enrolled during the molecular analysis study period*.

Characteristic	Value
Age, mo, mean ± SD (range)	51.8 ± 31 (2–180)
Gender ratio, M/F	1.06
Underlying disease, %†	4
Oral antimicrobial drugs before admission, %‡	29
Antimicrobial drug free before thoracocentesis, %§	23
PCV7 >1 dose, %	31
Referral, %	38

*PPE, pediatric parapneumonic empyema; PCV7, 7-valent pneumococcal conjugate vaccine.
†Underlying disease included (no. patients): lymphoma (2), congenital heart disease (2), mild psychomotor retardation (2), varicella zoster infection (2) and genetic disease (1).
‡Median duration: 3 d, range 1–17 d.
§100/147 children who had not been treated with oral antimicrobial drug therapy before admission received intravenous antimicrobial drug treatment before thoracocentesis for a median of 2 d (range 1–10 d).