Removing records on animals and nonhumans in Ovid Embase: a comparison of 11 filters.

Objective: To understand and compare the impact of 11 filters to remove records on animals or nonhumans in Ovid Embase, which are routinely used despite there being no performance data for them. To understand the indexing of relevant subject headings in Embase. Methods: To assess filter performance, we screened and categorized 3,000 records as 'should be removed' or 'should be retained' and calculated the sensitivity, specificity, and overall accuracy for each filter. We also reported on the number of records with human participants or data that were incorrectly removed by each filter. Results: Method 11 was the most sensitive, correctly retaining 90.6% records, whereas method 3 had the highest specificity, correctly removing 71.5% records. Of the records incorrectly removed by each filter, method 11 removed the fewest records with human participants or data at 10.9%, whereas method 3 removed the most at 14.3%. Filters that did not remove records indexed with 'nonhuman/' had higher sensitivity. Filter performance could vary by subject, publication type and language due to differences in indexing. Conclusion: In choosing a search filter, information specialists and review teams should discuss whether animals or nonhumans could feature in relevant studies.