Overview of combinations of trial registers/search portals that were searched in 80 Cochrane reviews.

<p>Overview of combinations of trial registers/search portals that were searched in 80 Cochrane reviews.</p

Overview of trial registers that were searched in 80 Cochrane reviews.

*<p>Most review authors searched in more than one register. Therefore, the summation of percentages exceeds 100%.</p

Methods applied for identification of trials in addition to searching in biomedical databases in 210 Cochrane reviews.

*<p>Most review authors applied multiple strategies to identify additional trials. Therefore, the summation of percentages exceeds 100%.</p