Table 2. Characteristics of investigated tests and reference standard used in selected studies.

Authors	Lytwyn et al.,17 2000	ALTS Group,7 2003	Andersson et al.,18 2005
Repeated cytological test:
Technique	Conventional	Liquid-based ThinPrep*	Conventional
Nomenclature	Bethesda, 1991	Bethesda, 1991	Bethesda, 1991
Colposcopic referral threshold	ASCUS, HSIL	HSIL	Any abnormality
HPV-DNA test:
Technique	HC2	HC2	HC2
Positivity cutoff	1 pg/ml	1 pg/ml	1 pg/ml
Reference standard	- Histological examination of colposcopy-directed biopsies and/or endocervical curettage - Colposcopy taken to be negative in the absence of specimens forwarded for histological evaluation	- Histological examination of colposcopy-directed biopsies, endocervical curettage and/or LEEP - Colposcopy taken to be negative in the absence of specimens forwarded for histological evaluation	- Histological examination of colposcopy-directed biopsies (in the absence of abnormal colposcopic findings, a biopsy was taken close to the squamocolumnar junction, at 12 o’clock)

^*Cytyc Corporation, Boxborough, Massachusetts, United States; ASCUS = Atypical Squamous Cells of Undetermined Significance; HSIL = High Grade Squamous Intraepithelial Lesions; HC2 = Hybrid Capture-2 (Qiagen Gaithersburg, Inc. Maryland, United States, previously Digene Corporation); LEEP = Loop electrosurgical excision procedure, including large loop excision of the transformation zone (LLETZ) or conization.