Effective use of FibroTest to generate decision trees in hepatitis C

Table 1 Clinical and laboratory data of the study population

Patients with chronic hepatitis C (n = 261)	Mean (range/SD)
Age (yr)	52 (20-78)
Age at infection (yr)	26.74 (birth-69)
Time of progression (yr)	26.41 (2-69)
Hemoglobin (g/dL)	14.83 ± 2.54
Platelet count (103/mm3)	203 ± 82
White cell count (103/mm3)	5.39 ± 1.82
γGT (IU/L)	77 ± 81
ALT (IU/L)	96.4 ± 108.1
Bilirubin (mg/dL)	0.9 ± 0.6

Table 2 Fibrosis stage (FibroTest) distribution according to gender in the study population n (%)

FibroTest score	Female	Male	Total
F0	16	4	20 (8)
F0-F1	5	4	9 (3)
F1	5	4	9 (3)
F1-F2	29	18	47 (18)
F2	21	13	34 (13)
F3	26	15	41 (16)
F3-F4	3	2	5 (2)
F4	44	52	96 (37)
Total	149 (57)	112 (43)	261 (100)

Table 3 Compound rules generated for classes F0 and F4 and the percentage of times that each rule was successfully applied

F0	F4
GGT ≤ 108 IU/L	Bilirubin > 1.2 mg/dL
A2M ≤ 280 g/L	GGT > 26 IU/L
Apo A1 > 144 g/L	A2M > 216 g/L
Age > 36 yr	Class F4 (95.6%)
Age ≤ 53 yr
Class F0 (79.4%)
	A2M > 335 g/L
	Haptoglobin ≤ 54.6 g/L
	Age > 53 yr
	Class F4 (95.5%)
Bilirubin ≤ 1.1 mg/dL
A2M ≤ 243 g/L
Apo A1 > 126 g/L
Haptoglobin > 73.5 g/L	Gender = M
Age ≤ 50 yr	Bilirubin > 0.5 mg/dL
Class F0 (77.7%)	A2M > 396 g/L
	Class F4 (91.7%)
	Bilirubin > 0.6 mg/dL
	Haptoglobin ≤ 16.2 g/L
	Class F4 (90.9%)
	GGT > 40 IU/L
	A2M > 372 g/L
	Age > 59 yr
	Class F4 (90.2%)

Table 4 Confusion matrix relating real FT scores (rows) to predicted FT scores (columns) in 261 patients with chronic hepatitis C

	F0	F0-F1	F1	F1-F2	F2	F3	F3-F4	F4
F0	18					2
F0-F1		9
F1			7			2
F1-F2	2			37	1	7
F2				3	18	13
F3						38		3
F3-F4						1	3	1
F4			1			3		92