Table 2: Characteristics of included studies

Author, year	Country (HCV prevalence*)	Setting and study period	Funding source and conflict(s) of interests	Study population	Study flow and timing	Index test	Reference test(s)
Denoyel et al.,¹⁵ 2004	France (low)	NR	NR	5228 participants: 5015 random blood donors and 213 inpatients	Not specified; based on results, all samples underwent both index and reference tests	CLIA (Advia Centaur HCV assay)	MEIA (AxSYM HCV version 3.0 assay, Abbott)
Tashkandy et al.,²² 2007	Saudi Arabia (high)	Immunology and Serology Department, Al-Noor Specialist Hospital, Makkah; study period NR	NR	106 male blood donors; samples from patients with diabetes or other endocrine diseases and autoimmune diseases excluded	All samples were aliquoted into 2 portions, 1 for PCR, the other for serological testing	ELISA version 3.0 (Murex anti-HCV, Abbott)	LIA (Inno-LIA HCV Ab III Update, Innogenetics) RT-PCR (high pure viral nucleic acid reagent set, Roche)
Benouda et al.,²³ 2009	Morocco (high)	Workplace blood specimen collection; December 2005 to April 2007	NR	8326 adults from general population with unknown HCV serology	Subset of 158/161 ELISA-positive and 100/8165 ELISA-negative adults recalled to undergo reference standard test (verification bias); 3/161 lost to follow-up; interval between tests not specified	ELISA version 3.0 (Murex anti-HCV, Abbott)	MEIA (AxSYM HCV version 3.0 assay, Abbott) RT-PCR (Amplicor HCV version 2.0, Roche)
Rao et al.,²⁴ 2009	China (high)	Beijing Red Cross Blood Center and Peking University Hepatology Institute; study period NR	Grants from Chinese Basic Research Foundation, National Science and Technology Key Project, and Key Clinical Research Program of Ministry of Health; conflict(s) of interest NR, but 1 author affiliated with Aldatis	2559 participants: 2082 blood donors and 477 patients including those with various HCV genotypes and non-C hepatitis, pregnant women and lipidemia serum samples	All samples underwent both index and reference tests "side-by-side"	ELISA version 4.0 (EIAgen, Adaltis)	ELISA version 3.0 (HCV version 3.0 ELISA test system, Ortho)
Ol et al.,²⁵ 2009	Cambodia (moderate)	Rural areas of 2 Cambodian provinces (Battambang and Pailin); May to June 2007	Sponsored by European Plasma Fraction Foundation and Tromsø Mine Victim Resource Center, University Hospital, North Norway; conflict(s) of interest NR	1200 potential volunteer blood donors: 677 women, 523 men, mean age 32.8 (range 18-52) yr; sample stratified by province (600 each)	Subset of 80/176 ELISA-positive and 40/1024 ELISA-negative samples selected to undergo reference test (verification bias); all samples underwent both index and reference tests	ELISA version 4.0 (Monolisa, BioRad)	CMIA (Abbott)
Kosan et al.,²⁶ 2010	Turkey (high)	Turkish Red Crescent Çapa Blood Centre of Istanbul; February 2007 to March 2008	None declared	18 200 volunteer blood donors: 546 women, 17 654 men, mean age 40 (range 18-60) yr, 18 198 were first-time donors; participants underwent mandatory physical examination before blood drawing	2 sets of blood samples collected from each participant: 1 underwent serological testing and the other, NAT testing	ELISA version 3.0 (Innotest HCV Ab III, Innogenetics)	NAT (Procleix Ultrio kit, Chiron)
Park et al.,²⁷ 2012	South Korea (low)	"Routine HCV screening"; August 2009 to January 2011	Funding source not reported, but Ortho provided CLIA assay kits; conflict(s) of interest NR	1011 serum samples from participants undergoing routine HCV screening	Not specified; based on results, all samples underwent both index and reference tests	CLIA (Vitros Anti-HCV assay, Ortho)	ECLIA (Elecsys anti-HCV test, Roche)
Sommese et al.,²⁸ 2014	Italy (low)	Second University of Naples; January to June 2013	None declared	840 volunteer blood donors: 275 women, 564 men,† mean age 37.7 yr	All samples underwent both index and reference tests in parallel	CMIA (Architect i2000SR, Abbott)	ECLIA (Cobas e411, Roche)
Arora et al.,²⁹ 2016	India (moderate)	Blood bank; January 2013 to March 2014	None declared	21 115 blood donors	All samples underwent both index and reference tests in parallel	ELISA version 4.0 (Monolisa HCV Ag-Ab Ultra, BioRad)	NAT (Procleix Ultrio kit, Chiron)

Note: CLIA = chemiluminescent immunoassay, CMIA = chemiluminescent microparticle immunoassay, ECLIA, electrochemiluminescent immunoassay, ELISA = enzyme-linked immunosorbent assay, HCV = hepatitis C virus, LIA = line immunoassay, MEIA = microparticle enzyme immunoassay, NAT = nucleic acid amplification test, NR = not reported, PCR = polymerase chain reaction, RT-PCR = reverse-transcription polymerase chain reaction.

*Low = < 1.5%, moderate = 1.5%-3.5%, high = > 3.5%.³⁰^{†As reported by the authors.}