Background: Searching trial registries is a mandatory item in the Cochrane MECIR guidelines, and two registries, the World Health Organization International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.Gov (CTG), are specifically recommended in the Cochrane Handbook of Systematic Reviews of Interventions (Chapter 4). As ICTRP contains records from CTG, a search of both resources will lead to duplicate records.

Automated tools and existing published deduplication methods are not suited to deduplicating registry records as they are based on comparison of fields such as title, author, journal name, year, and other metadata fields that are common to bibliographic records. Some of these fields are not commonly used in registry records, and even fields such as the title can differ across the same trial’s record from various sources.

Methods: This lightning talk will demonstrate the problem, including why software like Covidence fails at detecting duplicates between ICTRP and CTG. We will also present a method for deduplication of registry records in EndNote (desktop) using the unique study ID field as the sole deduplication parameter.

Conclusion: This method is particularly suited for librarians supporting reviews of interventions who have to search multiple resources that contain trials records (CTG, ICTRP, and even Cochrane CENTRAL).