Table 1.

Clinical factors, predisposing risk factors, severity factors, treatment factors, and outcome in pleural infection, in patients with microbiology negative or known etiology according to the initial antibiotic regimen

	Microbiology Negative					Known Etiology					p = §
	PENI	CEFU	broad	All	p = *	PENI	CEFU	broad	All	p = *
n=, (%)	62 (31)	101 (49)	37 (20)	200		57 (26)	106 (49)	49 (23)	216
Age (years)	59.7	62.9	57.7	60.8	0.27	63.5	65.5	62.5	64.3	0.37	0.02
para-pneumonic (%)	93.5	89	92	90.5	0.90	86	90.7	85.7	88.4	0.01	0.43
Nosocomial (%)	8.0	12	13.5	10.9	0.51	10.5	20	18.4	17.2	0.24	0.06
Risk factors (%)	44#	68#	54	59	0.22	59	73	80	71	0.45	0.009
AB before hospital admittance (%)	48	57	36	50.3	0.61	39	40	51	42.5	0.44	0.13
Severely ill (%)	4.8	5.0	37	11.1	< 0.001	10.7	5.7	32	13.2	0.0001	0.90
Thoracocentesis delay, median / mean (days)	4.5 /6.3	1 /3.6	2 /2.9	2.5 /4.7	0.01	2 /4.7	1 /2.9	1 /3.4	1/3.5	0.07	0.004
AB before thoracocentesis (%)	97#	80#	91	89.1	0.37	81	75	78	76.4	0.70	0.0008
AB treatment, median days	38.5	34	34.5	35	0.48	38	39.5	36.5	38	0.49	0.30
Pleural drainage delay > 2 days (%)	57	48	40	49	0.33	45	30	39	36	0.11	0.02
Fibrinolysis intrapleural (%)	27	33	28	30	0.71	40	31	31	34	0.45	0.43
ICU admittance (%)	4.8	2.0	18.9	5.9	< 0.001	5.3	1.9	25	7.9	< 0.0001	0.45
Mortality 30-day (%)	1.6	8.0	18.9	7.9	0.025	7.0	7.5	12.2	8.8	0.55	0.76
Mortality 90-day (%)	3.2	9.9	21.6	10.3	0.03	12.3	10.4	22.4	14.4	0.12	0.21
Surgery referral (%)	8.1	14.9	10.8	14.3	0.41	15.8	7.5	20.4	14.8	0.06	0.88
LOS, median (days)	15.5	15	19.5	16	0.25	19	18	19	18	0.49	0.22

AB antibiotics, ICU intensive care unit, LOS length of hospital stay

^*comparing three treatment regimens. ^§comparing all etiology-negatives and etiology-positives