Table 4.

Spearman’s correlation coefficient and prediction probability (PK) for the Observer’s Assessment of Alertness/Sedation (OAA/S) scale in 30 patients who underwent propofol anaesthesia.

Parameter	OAA/S
	Spearman’s coefficient		PK
	r	Statistical significance	Value	SE
BIS	0.898	P < 0.001	0.943	0.007
BISpro	0.806	P < 0.001	0.879	0.010a
HR	0.271	P < 0.001	0.617	0.019a,b
Ces	0.761	P < 0.001	0.852	0.011a

BIS, bispectral index; HR, heart rate; Ces, effect-site concentration of propofol; SE, standard error.

^aVersus BIS (P < 0.01); ^bversus BISpro (P < 0.01).