Table 3.

Risk of Bias Assessment of Included Studies

Title and Year	Quality of Allocation Concealment	Analysis on Intention to Treat	No. and Description of Dropouts	Blinding—Participants	Blinding—Health Care Providers	Blinding—Outcome Assessors	Comparable Treatment and Placebo Groups
Alborzi 200811	+	+	+	+	+	+	−
Sugden 200812	+	−	+	+	+	+	+
Witham 201013	+	U	+	+	+	+	+
Harris 201114	+	U	+	+	+	+	+
Gepner 201215	+	+	+	+	+	+	+
Larsen 201216	+	−	+	+	+	+	+
Marckmann 201217	+	−	+	+	+	+	+
Sokol 201218	+	+	U	+	+	+	+
Stricker 201219	+	+	+	+	+	+	−
Witham 201220	+	U	+	+	+	+	+
Breslavsky 201321	+	−	+	U	U	U	+
Hewitt 201322	+	U	+	+	+	+	+
Witham 201323	+	−	+	+	+	+	+
Witham 201324	+	+	+	+	+	+	+
Witham 201325	+	+	+	+	+	+	+
Yiu 201326	+	+	+	+	+	+	+
Dreyer 201427	+	+	+	+	+	+	+
Martins 201428	U	+	+	+	+	+	+
Mose 201429	+	U	+	+	+	+	+
Ryu 201430	U	−	+	+	+	+	+
Zoccali 201431	+	+	+	+	+	+	+
Garg 201532	U	−	+	+	+	+	+
Pilz 201533	+	+	+	+	+	+	+
Thethi 201534	U	U	U	+	+	U	+
Witham 201535	+	+	+	+	+	+	+
Barchetta 201636	+	−	+	+	+	+	+
Borgi 201737	+	+	−	+	+	+	+
Bressendorff 201638	+	U	+	+	+	+	+
Dalan 201639	+	+	U	+	+	+	−
Forouhi 201640	+	+	+	+	+	+	+
Hin 201741	+	+	+	+	+	+	+

− indicates high risk of bias; +, low risk of bias; U, unclear risk of bias.