Table 1. A comparison between both groups regarding pre-intervention characteristics.

Pre-intervention characteristics	Group A (non-surgical) =28	Group B (VATS) =38	Significance
Age	36 [18–72]	38.5 [19–65]	NS
Sex	22 M/6 F	30 M/8 F	NS
Cause of empyema	24 para-pneumonic (85.7%)	30 para-pneumonic (78.9%)	NS
Diabetes mellitus	6 patients (21.4%)	8 patients (21.1%)	NS
White cell count	15,200 [9,100–37,800]	14,900 [8,900–34,400]	NS
Stage of empyema	28 exudative phase (100%)	11 exudative/27 fibrino-purulent	<0.001

M, male; F, female; NS, not significant; VATS, video assisted thoracoscopic surgery.