标题：Searching ClinicalTrials.gov and the International Clinical Trials Registry Platform to inform systematic reviews: what are the optimal search approaches?
摘要：Background: Since 2005, Interna tional Committee ofMedical Journal Editors (ICMJE) member journalshave required that clinical trials be registered inpublicly available trials registers before they areconsidered for publication.Objectives: The research explores whether it isadequate, when searching to inform systematicreviews, to search for relevant clinical trials usingonly public trials registers and to identify the optimalsearch approaches in trials registers.Methods: AsearchwasconductedinClinicalTrials.gov and the International ClinicalTrials Registry Platform (ICTRP) for researchstudies that had been included in eight systematicreviews. Four search approaches (highly sensitive,sensitive, precise, and highly precise) wereperformed using the basic and advanced interfacesin both resources.Results: On average, 84% of studies were not listed ineither resource. The largest number of includedstudies was retrieved in ClinicalTrials.gov and ICTRPwhen a sensitive search approach was used in thebasic interface. The use of the advanced interfacemaintained or improved sensitivity in 16 of 19strategies for Clinicaltrials.gov and 8 of 18 for ICTRP.No single search approach was sensitive enough toidentify all studies included in the 6 reviews.Conclusions: Trials registers cannot yet be relied uponas the sole means to locate trials for systematic reviews.Trials registers lag behind the major bibliographicdatabases in terms of their search interfaces.Implications: For systematic reviews, trials registersand major bibliographic databases should besearched. Trials registers should be searched usingsensitive approaches, and both the registers consultedin this study should be searched
