Table 1.

List of excluded studies and reasons for their exclusion.

	Author	Year	Title	Reason for Exclusion
1	Boschetti G	2015 [24]	Accuracies of serum and fecal S100 proteins (calprotectin and calgranulin C) to predict the response to TNF antagonists in patients with Crohn’s disease.	The baseline status of the patients does not meet our requirements.
2	Lasson A	2013 [25]	Fecal calprotectin levels predict the clinical course in patients with new onset of ulcerative colitis.	The baseline status of the patients does not meet our requirements.
3	Yamamoto T	2015 [26]	Consecutive monitoring of faecal calprotectin during mesalazine suppository therapy for active rectal inflammation in ulcerative colitis.	The baseline status of the patients does not meet our requirements.
4	Brooks AJ	2017 [27]	Outcome of elective withdrawal of anti-tumour necrosis factor-α therapy in patients with Crohn’s disease in established remission.	Absence of data to reconstruct 2 × 2 table.
5	De Vos M	2011 [28]	Fast and sharp decrease in calprotectin predicts remission by infliximab in anti-TNF naïve patients with ulcerative colitis.	Bring FC into gold standard.
6	Sollelis E	2019 [29]	Combined evaluation of biomarkers as predictor of maintained remission in Crohn’s disease.	Bring FC into gold standard.
7	Reinisch W	2019 [30]	Fecal Calprotectin Responses Following Induction Therapy With Vedolizumab in Moderate to Severe Ulcerative Colitis: A Post Hoc Analysis of GEMINI 1.	Without cut-off value.
8	Mooiweer E	2015 [31]	Low fecal calprotectin predicts sustained clinical remission in inflammatory bowel disease patients: a plea for deep remission.	Including children (<16 y).
9	Molander P	2014 [32]	Does fecal calprotectin predict short-term relapse after stopping TNFα-blocking agents in inflammatory bowel disease patients in deep remission?	The recurrence was predicted by FC value over a period of time.
10	Garcia-Planella E	2018 [33]	Serial semi-quantitative measurement of fecal calprotectin in patients with ulcerative colitis in remission.	Patients’ numbers are inconsistent.
11	Tursi A	2019 [34]	Vedolizumab is effective and safe in real-life treatment of inflammatory bowel diseases outpatients: A multicenter, observational study in primary inflammatory bowel disease centers.	No statistics about relapse.
12	Bertani L	2020 [35]	Fecal Calprotectin Predicts Mucosal Healing in Patients With Ulcerative Colitis Treated With Biological Therapies: A Prospective Study.	No statistics about relapse.
13	Bertani L	2020 [36]	Serum oncostatin M at baseline predicts mucosal healing in Crohn’s disease patients treated with infliximab.	No statistics about relapse.
14	Guidi L	2014 [37]	Faecal calprotectin assay after induction with anti-Tumour Necrosis Factor α agents in inflammatory bowel disease: Prediction of clinical response and mucosal healing at one year.	No statistics about relapse.
15	Beswick L	2018 [38]	Exploration of Predictive Biomarkers of Early Infliximab Response in Acute Severe Colitis: A Prospective Pilot Study.	No statistics about relapse.
16	Reinisch W	2020 [39]	Association of Biomarker Cutoffs and Endoscopic Outcomes in Crohn’s Disease: A Post Hoc Analysis From the CALM Study.	No statistics about relapse.