Risk of venous thromboembolism in children and adolescents with inflammatory bowel disease: A systematic review and meta-analysis

Table 1 Characteristics of the included studies: ulcerative colitis patients and Crohn’s disease patients

Ref.	Country	Study design	Period	Sample size N	Age, years (mean or median)	Male, (%)	Patient	IBD therapy	VTE type
Antiel et al[31], 2013	United States	Cohort	1999.1-2011.12	366	≤ 21	No data	UC	Surgery	IAT
Bence et al[26], 2020	United States	Cohort	2020.1-2016.6	276	15 (13, 17)	46	CD, UC, IC	Corticosteroids, Biologic therapy, Immunologic therapy	DVT
Cairo et al[36], 2017	United States	RCS	2012-2015	410	< 1 (9.8%); 1-5 (15.7%); 6-10 (30%); 11-15 (34.6%); 16-18 (9.9%)	59.5	IBD	No data	VTE
Derderian et al[27], 2020	United States	Cohort	2008-2018	49	9.8 ± 4.4	65	UC/IBD-U	Surgery	DVT
Diamond et al[32], 2018	United States	Cohort	2015-2017	47	14	46.8	IBD	Systemic steroids; Anti-TNF therapy	CVC-related thrombosis
Diamond et al[33], 2010	Canada	Cohort	1999.11.1-2008.2.29	85	14.8 (2.8)	54.1	IBD	Surgery	DVT
Herzog et al[34], 2018	Switzerland	Cohort	2006-2017	63	< 17	54	CD; UC or IBD-U	5-ASA Systemic CS; Immunomodulators; Calcineurin inhibitors; TNFα inhibitors, Surgery	TE
Jarchin et al[29], 2019	United States	Cohort	2008.1-2017.12	58	0-5 (5%); 6-10 (10%); 11-18 (85%)	66	UC	Anti-TNF only, Vedolizumab only, Anti-TNF+ vedolizumab, Anti-TNF+ vedolizumab+ ustekinumab, Surgery	PVT (within 30 d, > 30 d)
Khosravi et al[28], 2020	Iran	Cohort	2019	21	11.12 ± 5.65	42.9	IBD	Surgery	DVT
Lee et al[35], 2016	Korea	Cohort	1995.7-2011.6	73	12.49 ± 2.47	71.2	CD	Systemic corticosteroids 5-ASA only, 5-ASA+; azathioprine; 5-ASA only or 5-ASA+ azathioprine	PTE
Nylund et al[19], 20131	United States	Database review	1997, 2000, 2003, 2006, and 2009	61076/7318/7379898	15.72 ± 0.02/15.39 ± 0.06/13.57 ± 0.01	49.32/47.55/49.64	CD, UC	No data	TE, PE, DVT, IVST, PVT
Zitomersky et al[37], 2013	United States	Database review	2006-2011	532	No data	No data	CD, UC	No data	CVT

¹Adjusted factors: Age category, sex, hypercoagulable status, central venous catheter, parenteral nutrition, any cancer, sickle cell anemia, tobacco use, race/ethnicity, payer status, urban/rural status, hospital region, and year of inpatient stay.

DVT: Deep venous thrombosis; CD: Crohn’s disease; UC: Ulcerative colitis; IC: Indeterminate colitis; VTE: Venous thromboembolism; PE: Pulmonary embolism; RCS: Retrospective comparative study; CVC: Central venous catheter; PTE: Pulmonary thromboembolism; IVST: Intracranial venous sinus thrombosis; PVT: Portal vein thrombosis; TE: Thromboembolic events; IAT: Intra-abdominal thrombosis; CVT: Cerebrovascular thrombosis.

Table 2 Quality assessment

Ref.	Representativeness of the exposed cohort	Selection of the non-exposed cohort	Ascertainment of exposure	Demonstration that outcome of interest was not present at start of study	Comparability of cohorts on the basis of the design or analysis	Assessment of outcome	Was follow-up long enough for outcomes to occur	Adequacy of follow-up of cohorts	Total quality scores
Antiel et al[31], 2013	1	0	1	1	0	1	1	1	6
Bence et al[26], 2020	1	0	1	1	0	1	1	1	6
Cairo et al[36], 2017	1	1	1	1	1	1	1	1	8
Derderian et al[27], 2020	1	0	1	1	0	1	1	1	6
Diamond et al[32], 2018	1	0	1	1	0	1	1	1	6
Diamond et al[33], 2010	1	0	1	1	0	1	1	1	6
Herzog et al[34], 2018	1	0	1	1	0	1	1	1	6
Jarchin et al[29], 2019	1	0	1	1	0	1	1	1	6
Khosravi et al[28], 2020	1	0	1	1	0	1	1	1	6
Lee et al[35], 2016	1	0	1	1	0	1	1	1	6
Nylund et al[19], 2013	1	1	1	1	2	1	1	1	9
Zitomersky et al[37], 2013	1	0	1	1	0	1	1	1	6