Table 2.

Diagnostic performance of blood-based and imaging-based NITs for the assessment of AF

Test	Formula or method	AUROC for AF	Cut-off for AFa	Sensitivity (95% CI)	Specificity (95% CI)	Population (T2D/mixed)	Reference
FIB-4	$\frac{\mathrm{Age}(\mathrm{years})\times \mathrm{AST}(\mathrm{IU}/\mathrm{l})}{\mathrm{Platelets}(\mathrm{E}9/\mathrm{l})\times \sqrt{\mathrm{ALT}(\mathrm{IU}/\mathrm{l})}}$	0.75	1.30	73 (69, 76)	62 (59, 65)	T2D	[53]
			2.67	23 (20, 26)	93 (92, 95)
ELF	Proprietary blood test analysing HA, PIIINP and TIMP-1	0.83	7.7	93 (82, 98)	34 (13, 65)	Mixed	[54]
			9.8	65 (49, 77)	86 (77, 92)
			11.3	36 (15, 63)	96 (90, 99)
LSM-VCTE	Ultrasound-based method; proprietary hardware and software	0.82	8.0 kPa	88 (86, 90)	56 (53, 60)	T2D	[53]
			9.7 kPa	77 (74, 80)	71 (68, 74)
			12.1 kPa	55 (52, 57)	90 (89, 91)	Mixed	[55]
LSM-MRE	MRI-based method; proprietary hardware and software	0.92	3.53 kPab	87 (80, 92)	88 (81, 94)	Mixed	[56]

All of the diagnostic accuracy studies cited here used liver biopsy as the reference standard

^aFor a given cut-off, values equal to or greater than the cut-off are considered positive, and values less than the cut-off are considered negative

^bThe 3.53 kPa cut-off for LSM-MRE was optimised in the latest individual participant data meta-analysis by Liang et al [56]. A cut-off of 3.62 kPa has been widely used to identify AF, and it had a sensitivity of 78% (95% CI 66, 88) and specificity of 88% (95% CI 82, 92) in the same study

ALT, alanine aminotransferase; AST, aspartate aminotransferase; AUROC, area under the receiver operating characteristic curve; HA, hyaluronic acid; PIIINP, procollagen III amino-terminal peptide; TIMP-1, tissue inhibitor of matrix metalloproteinase 1; T2D, type 2 diabetes