Removing animal and nonhuman records in Ovid Embase: A comparison of 11 filters

ABSTRACT Introduction Several filters are routinely used to remove animal or nonhuman records in Ovid Embase, despite there being no performance data for them. The filters take different approaches in design. Objective To understand and compare the impact of 11 filters to remove animal or nonhuman records in Ovid Embase. To understand the indexing of relevant subject headings in Embase. Methods To assess filter performance, we screened and categorised 3,000 records as ‘should be removed’ or ‘should be retained’ and calculated the sensitivity, specificity and overall accuracy for each filter. We reported on the focus or content of records that were incorrectly removed, using seven categories. Results Method 11 was the most sensitive, correctly retaining 90.6% records, whereas method 3 had the highest specificity, correctly removing 71.5% records. Out of seven categories, those in category 1 ‘uses human participants or data’ were the most excluded. Discussion Filters that did not remove nonhuman records 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.