Incidence of umbilical vein catheter-associated thrombosis of the portal system: A systematic review and meta-analysis

Table 1 Risk of bias assessment (Newcastle-Ottawa scale for non-randomized studies)

Ref.	Selection	Comparability	Outcome	Total score
Levit et al[42], 2020	4	2	3	9
Dubbink-Verheij et al[31], 2020	4	2	3	9
Chen et al[15], 2020	4	0	3	7
Hwang et al[46], 2020	4	2	3	9
Çakır et al[38], 2020	4	0	3	7
Cabannes et al[32], 2018	4	2	3	9
Derinkuyu et al[5], 2018	4	0	3	7
Chandrashekhar et al[45], 2015	4	0	3	7
Michel et al[37], 2012	4	2	3	9
Gharehbaghi et al[39], 2011	4	2	3	9
Sakha et al[41], 2007	4	2	3	9
Turebylu et al[21], 2007	4	2	3	9
Kim et al[30], 2001	4	2	3	9
Boo et al[44], 1999	4	2	3	9
Schwartz et al[40], 1997	4	0	3	7
Yadav et al[43], 1993	4	0	2	6

Table 2 Characteristics of included studies

Ref.	Study design	UVC with PVT	UVC without PVT	Dwel time UVC with PVT	Dwel time UVC without PVT	Indication to UVC control	Type of imaging	Country/territory
Levit et al[42], 2020	Prospective	1	2016	N/A	N/A	Clinical Suspicion	X-ray + US	United States
Dubbink-Verheij et al[31], 2020	Prospective	13	27	N/A	N/A	Screening	X-ray + US	The Netherlands
Chen et al[15], 2020	Retrospective	7	1320	N/A	N/A	Screening	X-ray + US	Taiwan
Hwang et al[46], 2020	Retrospective	15	54	N/A	N/A	Screening	X-ray + US	South Korea
Çakır et al[38], 2020	Prospective	13	83	10.5 ± 4.31	12.2 ± 4.11	Screening	X-ray + US	Turkey
Cabannes et al[32], 2018	Prospective	51	53	N/A	N/A	Screening	X-ray + US	France
Derinkuyu et al[5], 2018	Prospective	15	229	N/A	N/A	Screening	X-ray + US	Turkey
Chandrashekhar et al[45], 2015	Prospective	3	27	N/A	N/A	Screening	X-ray + US	India
Michel et al[37], 2012	Prospective	2	59	N/A	N/A	Screening	X-ray + US + Echocardiography	France
Gharehbaghi et al[39], 2011	Prospective	5	159	N/A	N/A	Screening	X-ray + US	Iran
Sakha et al[41], 2007	Prospective	17	33	2 ± 1.121	N/A	Screening	US	Iran
Turebylu et al[21], 2007	Prospective	2	26	N/A	6	Screening	X-ray + US	United States
Kim et al[30], 2001	Prospective	43	57	> 6 d in 23/43	> 6 d in 6/57	Screening	X-ray + US	South Korea
Boo et al[44], 1999	Prospective	0	57	N/A	N/A	Screening	X-ray + US	Malaysia
Schwartz et al[40], 1997	Prospective	1	99	3	4 (0-12)2	Screening	X-ray + US	United States
Yadav et al[43], 1993	Prospective	7	15	N/A	N/A	Screening	X-ray + US	India

¹Results are expressed as mean ± SD, if reported.

²Results are expressed as median (range), if reported.

UVC: umbilical venous catheter; PVT: portal vein thrombosis; N/A: Not applicable; US: Ultrasound (abdominal).