Table 6.

Cutoffs and predictive values

Value	ESR (mm/hr)	CRP (mg/L)	Synovial fluid WBC count (per μl)	% PMN
Optimum cutoff	43.5	17.75	1102.5	71.5
Sensitivity	0.67	0.17	0.75	0.75
Specificity	0.62	0.94	0.61	0.66
PPV	0.13	0.20	0.11	0.12
NPV	0.05	0.07	0.03	0.02
Accuracy	0.62	0.88	0.62	0.66
Area Under Curve	0.62	0.39	0.71	0.62