Reevaluating aminosalicylates role in maintaining remission in ulcerative colitis: Systematic review and meta-analysis in the era of biologics

Table 1 Risk of bias summary: Review authors' judgments about each risk of bias item for each included study

Ref.	Random sequence generation (selection bias)	Allocation concealment (selection bias)	Blinding (performance bias & detection bias): All outcomes	Incomplete outcome data (attrition bias): All outcomes	Selective reporting	Other bias
D'Haens et al[37], 2012	?	+	+	+	+	+
Dignass et al[38], 2009	?	+	-	+	+	+
Hawthorne et al[32], 2012	?	?	-	?	+	+
Ito et al[48], 2010	+	+	+	+	+	+
Kamm et al[39], 2008	?	+	-	+	+	+
Kane et al[43], 2008	+	+	-	+	+	+
Kruis et al[40], 2009	+	+	+	+	+	+
Paoluzi et al[34], 2005	?	?	+	+	+	+
Park et al[45], 2016	+	+	?	+	+	+
Pica et al[35], 2015	?	?	-	?	?	?
Prantera et al[47], 2009	+	+	+	+	+	+
Sandborn et al[41], 2010	?	+	-	+	+	+
Suzuki et al[46], 2017	+	+	+	+	+	+
Watanabe et al[36], 2013	?	?	+	+	?	+

Symbols: “+”: Low risk; “-”: High risk; “?”: Unclear risk.