Effects of patient factors on noninvasive liver stiffness measurement using acoustic radiation force impulse elastography in patients with chronic hepatitis C

Table 4 Factors associated with false positivity in patients with METAVIR F1, F2 and F3

Variable	Non FP	FP	OR(95% CI)	Pvalue
Variable	n = 77	n = 32	OR(95% CI)	Pvalue
Age, year	50.8(1.4)	53.4(2.0)		.316
Gender, male/female (n)	35/42	16/16		.679
BMI, kg/m²	24.34(0.37)	25.37(0.68)		.155
HCV genotype, 1/non-1 (n)	38/39	15/17		.836
HCV RNA, x 10⁶, copies/mL	7.14(1.12)	10.61(3.12)		.194
ALT, IU/L	83.01(9.40)	133.88(15.02)		.004
ALT/ULN (n)
<1x	24	2	reference
≧1x <2x	25	10	4.8(0.9-24.2)	.057
≧2x <3x	16	5	3.8(0.6-21.7)	.140
≧3x	12	15	15.0(2.9-76.6)	.001*
ActiTest A score (n)				.
0.00-0.35	31	2	reference
0.36-0.75	24	13	8.4(1.7-40.8)	.008*
0.76-1.00	22	17	11.9(2.5-57.2)	.002*
Bilirubin, umol/L	15.76(0.56)	19.30(1.12)		.002
Cr, umol/L	70.82(2.82)	74.14(4.55)		.817
INR	1.00(0.01)	1.05(0.02)		.007
Na, meq/L	137.94(0.28)	137.81(0.46)		.527
Platelet, x 10⁹/L	184.21(6.20)	158.31(9.37)		.025
METAVIR F1/2/3 (n)	38/32/7	8/8/16		<.001
METAVIR A (n)
A0	28	3	reference
A1	45	15	3.1(0.8-11.7)	.094
A2-3	4	14	32.7(6.4-166.5)	<.001*
Hepatic steatosis S0/1/2/3/4(n)	10/28/35/3/1	5/9/17/1/0		.903
Liver SWV, m/s	1.34(0.03)	2.40(0.11)		<.001
FibroTest, F score	0.51(0.03)	0.72(0.04)		<.001

Thirty-two patients of the 109 patients with METAVIR F1, F2 and F3 were false positive (32/109, 29%) in liver fibrosis evaluation using acoustic radiation force impulse elastography. False positive case numbers were: 8 (8/46, 17%) (ARFI LSM > 1.55 m/s) in METAVIR F1; 8 (8/40, 25%) (LSM > 1.81 m/s) in F2; 16 (16/23, 70%) (LSM > 1.98 m/s) in F3 stages. Continuous variables were presented as mean (standard error) and examined using the Student’s t-test. Categorical variables were estimated using Fisher's exact test or univariate binary logistic regression*. ALT, serum alanine aminotransferase; ARFI, acoustic radiation force impulse; CI, confidence interval; Cr, serum creatinine; FP, false positivity; INR, international normalized ratio of prothrombin time; LSM, liver stiffness measurement; METAVIR A, activity; METAVIR F, fibrosis; Na, serum sodium; non FP, true positive + true negative + false negative; OR, odds ratio; SWV, shear wave velocity.

ISSN: 1471-230X