Table 2. Two-step cluster analysis of patient data.

Variables	Cluster 1 (n = 11)	Cluster 2 (n = 16)	Cluster 3 (n = 12)
Patient survival (%)	0%	100%	100%
Patients developing VAP (n,%)	2, 18.2%	13, 81.8%	0, 0%
Biomass visible on ETT (n,%)	9, 81.8%	8, 50%	12, 100%
ETT culture results (n,%)	P. aeruginosa (7, 63.6%)	P. aeruginosa (2, 12.5%)	P. aeruginosa (4, 33.3%)
	S. epidermidis (4, 36.4%)	S. epidermidis (9, 56.25%)	S. epidermidis (8, 66.7%)
		Both (5, 31.25%)
APACHE II scores (average)	26.55	25.5	18.5
Age (average in years)	67.82	57.69	60.5
Duration of intubation in days (average)	12.45	13.69	11.42

Variables are listed in order of importance.