Table 4

- Overall assessment of risk of bias using Cochrane Collaboration Risk of Bias Tool of randomized-controlled trials in countries* under Gulf Cooperation Councils from 1990 to 2018 (n=406).

Variables	n	%
Random sequence generation
Unclear risk	156	38.4
Low risk	192	47.3
High risk	58	14.3
Allocation concealment
Unclear risk	227	55.9
Low risk	101	24.9
High risk	78	19.2
Selective reporting
Unclear risk	76	18.7
Low risk	328	80.8
High risk	2	0.5
Other sources of bias
Unclear risk	320	78.8
Low risk	60	14.8
High risk	26	6.4
Blinding of participants and personnel
Unclear risk	89	21.9
Low risk	141	34.7
High risk	176	43.4
Blinding of outcome assessment
Unclear risk	172	42.3
Low risk	131	32.3
High risk	103	25.4
Incomplete outcome data
Unclear risk	26	6.4
Low risk	340	83.7
High risk	40	9.9
Overall risk of bias
Unclear risk	185	45.6
High risk	221	54.4

*Saudi Arabia, Bahrain, United Arab of Emirates, Kuwait, Oman, and Qatar