Table 3.

Item response probabilities in latent class analysis

		Class 1	SE	Class 2	SE
		Estimate		Estimate
White blood cell count (/μL)	≤6,000	0.10	0.03	0.05	0.03
	6000–12,000	0.42	0.05	0.29	0.09
	12,000<	0.48	0.05	0.67	0.10
Serum ferritin (ng/mL)	≤500	0.10	0.03	0.04	0.04
	500–5000	0.40	0.05	0.22	0.07
	5000<	0.50	0.05	0.74	0.08
Serum C-reactive protein (mg/dL)	≤0.3	0.01	0.01	0.00	0.00
	0.3–10	0.55	0.05	0.25	0.09
	10<	0.44	0.05	0.75	0.09
Age (years)	≤50	0.64	0.08	0.15	0.07
	50<	0.36	0.08	0.85	0.07
Splenomegaly	Presence	0.61	0.08	0.24	0.08
Hepatomegaly	Presence	0.40	0.07	0.13	0.06
Sore throat	Presence	0.68	0.05	0.53	0.08
Arthritis	Presence	0.82	0.04	0.75	0.07
Pericarditis	Presence	0.00	0.01	0.23	0.09
Pleuritis	Presence	0.01	0.01	0.37	0.12
Macrophage activating syndrome	Presence	0.20	0.04	0.27	0.07
Typical rash	Presence	0.64	0.05	0.37	0.1

SE standard error