Table 2 Extracted information to evaluate the research question

Funding source

[Industry/independent]

Experimental intervention is reported to be superior to the control intervention

[Yes/no]

Exact p value of the primary endpoint

[n]

Year of publication

[n]

Impact factor of journal

[n]

Region

[National/multinational]

Number of study centres

[n]

Sample size

[n]

Concluded superiority without statisticalsignificance of primary endpoint

[Yes/no]

Risk of bias for primary endpoint according to Cochrane Collaboration’s tool for assessing risk of bias

[Low/high/unclear]