Table 1.

Basic characteristics and quality assessment of included studies.

Study	Design	Age (years)	Region (subgroup)	HPV type	HPV infection time	Indexes	Follow-up time (months)	Quality rating
Sagasta et al. (2016) [10]	Prospective	33 ± 10	Spain (Europe)	HR-HPV	NR	①②③	28	8
Veijalainen et al. (2015) [11]	Retrospective	40.4	Finland (Europe)	HR-HPV	NR	①	96	8
He et al. (2015) [12]	Retrospective	35 ± 16.93	China (Asia)	HR-HPV	NR	①②③	15 (8–24)	9
Zhou et al. (2015) [13]	Prospective	37.57 ± 9.12	China (Asia)	HR-HPV	NR	③	24	7
Mou et al. (2014) [14]	Retrospective	38.18 ± 4.26	China (Asia)	NR	NR	①②③	36	7
Siriaunkgul et al. (2014) [15]	Prospective	46.6	Thailand (Asia)	NR	NR	①②③	24	8
Hu et al. (2014) [16]	Prospective	30–59	China (Asia)	HR-HPV	Transient	①②③	24	9
					Persistent	①②③
Jiang (2013) [17]	Retrospective	39.16 ± 8.97	China (Asia)	HR-HPV	NR	①②③	24	8
Waldstrøm et al. (2013) [18]	Prospective	32.3	Denmark (Europe)	NR	NR	①②③	60	8
Katki et al. (2013) [19]	Prospective	30–64	United States (America)	NR	NR	①②③	60	8
Byun et al. (2013) [20]	Prospective	46	Korea (Asia)	HR-HPV	NR	①	8	8
Liao et al. (2013) [21]	Prospective	30–49	China (Asia)	HR-HPV	NR	①	36	8
Li et al. (2013) [22]	Prospective	38	China (Asia)	HR-HPV	NR	③	6	8
Wang et al. (2012) [6]	Retrospective	35.4 (20–53)	China (Asia)	HR-HPV	Persistent	①	18.6 (8–24)	9
Huang et al. (2012) [23]	Retrospective	30 (22–70)	China (Asia)	HR-HPV	NR	①	24	7
Bowring et al. (2012) [24]	Prospective	36.8 ± 10.2	Britain (Europe)	HR-HPV	NR	①②③	12	8
Jakobsson et al. (2012) [25]	Retrospective	34	Finland (Europe)	HR-HPV	NR	①	6	8
Ozaki et al. (2011) [26]	Prospective	39	Japan (Asia)	NR	NR	①	17	7
Li and Yang (2011) [5]	Prospective	30 ± 2.32	China (Asia)	HR-HPV	NR	①②③	6	8
				LR-HPV		②③
Gonzalez-Bosquet et al. (2010) [27]	Prospective	32.25	Germany (Europe)	HR-HPV	NR	①	25	7
Waldstrøm and Ømskov (2010) [28]	Retrospective	32	Denmark (Europe)	NR	NR	①②③	36	8
Heider et al. (2010) [29]	Retrospective	33	United States (America)	HR-HPV	NR	①②③	34	9
Cotton et al. (2010) [30]	Prospective	20–59	Britain (Europe)	HR-HPV	NR	①	36	8
Thrall et al. (2009) [7]	Prospective	≥30	United States (America)	HR-HPV	NR	①②③	24	9
Liao (2008) [31]	Prospective	30–49	China (Asia)	HR-HPV	NR	③	24	7
Gong (2007) [1]	Prospective	38.37 ± 5.26	China (Asia)	HR-HPV	Transient	①②③	24	7
					Persistent	①②③
Luis Ferreira Santos et al. (2006) [32]	Prospective	31 (16–63)	United States (America)	NR	NR	①②③	12	8
Tarkkanen et al. (2006) [33]	Prospective	35 (20–60)	Finland (Europe)	NR	NR	①	6	7
Song et al. (2006) [34]	Retrospective	38	Korea (Asia)	NR	NR	①②③	24	8
Clavel et al. (2005) [35]	Retrospective	30	France (Europe)	HR-HPV	NR	①②③	24	8
Massad et al. (2004) [36]	Prospective	37.4	United States (America)	HR-HPV	NR	①②③	90	8
				LR-HPV	NR	①②③
Sastre-Garau et al. (2004) [37]	Retrospective	31	France (Europe)	HR-HPV	NR	①③	24	8
Alameda et al. (2004) [38]	Retrospective	25–45	Spain (Europe)	HPV	NR	②③	24	7
Schlecht et al. (2003) [39]	Retrospective	16–65	Brazil (America)	HR-HPV	NR	①	53.3	8
				LR-HPV	NR	①
Denise Zielinski et al. (2001) [40]	Retrospective	40.5 (20–76)	Holland (Europe)	HR-HPV	NR	①②③	16.8 (0–54)	8
Matsuura et al. (1997) [41]	Prospective	NR	United States (America)	NR	NR	①②③	89.2 ± 25.2	8
Kaufman et al. (1997) [42]	Retrospective	NR	United States (America)	HR-HPV	NR	①③	6	7
Campion et al. (1986) [43]	Prospective	<30	Britain (Europe)	NR	NR	①②③	22.4 (19–30)	7

Note. ①: the relative risk (RR) of progression of CIN1 patients of HPV-positive compared with the HPV-negative; ②: the relative risk (RR) of persistence of CIN1 patients of HPV-positive compared with the HPV-negative; ③: the relative risk (RR) of regression of CIN1 patients of HPV-positive compared with the HPV-negative. HPV, human papillomavirus; HR-HPV, high-risk HPV; LR-HPV, low-risk HPV; HPV(+), HPV-positive; NR, not reported.