Table 2. Laboratory values according to culture for septic arthritis status.

	Negative (N=25)	Positive (N=40)	AUC (95% CI)	p value
% Neutrophils	86 (4, 98)	93 (5, 100)	0.65 (0.52, 0.79)	0.041
ESR at Diagnosis	32 (1, 120)	49.5 (2, 145)	0.61 (0.44, 0.78)	0.21
CRP at diagnosis	34.20 (1.10, 352.60)	142.30 (2.60, 400.0)	0.66 (0.50, 0.83)	0.051
WBC at diagnosis	8.89 (4.00, 20.30)	10.00 (5.20, 15.40)	0.51 (0.34, 0.68)	0.89
Cell count from aspiration	35385 (157, 333000)	32435 (33, 260000)	0.51 (0.36, 0.66)	0.94
CI=confidence interval, ESR = erythrocyte sedimentation rate, CRP = C-reactive protein, WBC = white blood cell count. Continuous variables are summarized with median (range), and categorical variables are summarized with number (%). Twelve patients were missing ESR at diagnosis, fifteen patients were missing CRP at diagnosis, and four patients were missing WBC at diagnosis. P-values less than 0.05 are considered statistically significant and are shown in bold.