Sodium picosulphate or polyethylene glycol before elective colonoscopy in outpatients? A systematic review and meta-analysis

Table 2 Assessment of risk of bias by JADAD scale

#	STUDY	Randomized? (1 pt)	Randomization method	Adequate randomization? (1 pt)	Double blind? (1 pt)	Masking method	Adequate masking? (1 pt)	Loss description? (1 pt)	Jadad (0-5 pts)	GENERAL QUALITY
1	Regev et al[34]	Yes	Randomization per patients' ID (odd or even numbers)	No	No	Endoscopist blind for the preparation regimen	No	Yes	2	Intermidiate
2	Lawrance et al[35]	Yes	Randomized using Generator Pro 1.69 (Segobit software) in ratio 2:1:1 (PEG:NaP:Pico)	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
3	Kao et al[36]	Yes	Randomization in blocks of 8 and stratified per AM/PM using a computer-generated table	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
4	Katz et al[15]	Yes	Randomization numbers allocated sequentially by voice system	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
5	Manes et al[37]	Yes	Randomization by computer-generated sequence	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
6	Rex et al[15]	Yes	Randomization numbers allocated sequentially by voice system	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
7	Jeon et al[38]	Yes	Randomization by computer-generated table	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
8	Kang et al[39]	Yes	Randomization in blocks using website randomization.com	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
9	Kim et al[40]	Yes	Not described	No	No	Endoscopist blind for the preparation regimen	No	No	1	Low
10	Kim et al[41]	Yes	Randomization by computer-generated sequence	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
11	Leitao et al[28]	Yes	Randomization 1:1 with blocks of 10 by endoscopy-unit secretary	Yes	No	Endoscopist blind for the preparation regimen	No	No	2	Intermidiate
12	Kim et al[29]	Yes	Randomization by computer-generated table	Yes	No	Not described	No	No	2	Intermidiate
13	Munsterman et al[30]	Yes	Randomization by computer-generated 1:1 stratified by age (18-64) or (65-80)	Yes	No	Endoscopist blind for the preparation regimen	No	No	2	Intermidiate
14	Pohl et al[31]	Yes	Randomization 1:1 in blocks of 4 by statistician list-generated	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
15	Yoo et al[32]	Yes	Randomization 1:1 in blocks of 4 by a a computer-generated list	Yes	No	Endoscopist blind for the preparation regimen	No	Yes	3	High
16	Kojecky et al[33]	Yes	Randomization 1:1 using a software generated random table	Yes	No	Endoscopist blind for the preparation regiment	No	Yes	3	High