Searching ClinicalTrials.gov and the International Clinical Trials Registry Platform to inform systematic reviews: what are the optimal search approaches?

Background:

Since 2005, International Committee of Medical Journal Editors (ICMJE) member journals have required that clinical trials be registered in publicly available trials registers before they are considered for publication.

Objectives:

The research explores whether it is adequate, when searching to inform systematic reviews, to search for relevant clinical trials using only public trials registers and to identify the optimal search approaches in trials registers.

Methods:

A search was conducted in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) for research studies that had been included in eight systematic reviews. Four search approaches (highly sensitive, sensitive, precise, and highly precise) were performed using the basic and advanced interfaces in both resources.

Results:

On average, 84% of studies were not listed in either resource. The largest number of included studies was retrieved in ClinicalTrials.gov and ICTRP when a sensitive search approach was used in the basic interface. The use of the advanced interface maintained or improved sensitivity in 16 of 19 strategies for Clinicaltrials.gov and 8 of 18 for ICTRP. No single search approach was sensitive enough to identify all studies included in the 6 reviews.

Conclusions:

Trials registers cannot yet be relied upon as the sole means to locate trials for systematic reviews. Trials registers lag behind the major bibliographic databases in terms of their search interfaces.

Implications:

For systematic reviews, trials registers and major bibliographic databases should be searched. Trials registers should be searched using sensitive approaches, and both the registers consulted in this study should be searched.Clinical trials registers such as ClinicalTrials.gov and portals to trials registers such as the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) are increasingly used to identify ongoing or completed clinical trials. These resources offer important information on the methods and progress of trials likely to be of interest to a range of users, including researchers, clinicians, and patients. The extent to which these resources can be relied upon as a sole source of trials for inclusion in systematic reviews, including Cochrane systematic reviews (CSRs), is the subject of the research study reported here. This study also investigates the most efficient ways that librarians, information professionals, and other searchers can search these resources. Search efficiency was investigated by evaluating the overlap and unique yield of searches in the two resources and by testing four search approaches. The tested search approaches ranged from the very precise (single specific condition search term combined with a single specific intervention search term) to the very sensitive (at least two interventions terms).     

The end of reckoning – archival silences in the Germaine Greer Archive

The Germaine Greer Archive was created by Greer in the 1970s to document her career and provide-counter evidence against false claims about her work and personal life. Later attempts to address gaps in the archive in relation to her television career were hampered by the poor record keeping of production companies and film and television archives. The archive documents both an attempt to create a complete record and the deliberate creation of a counter-narrative through arrangement and juxtaposition of records.     

Do published search filters to identify diagnostic test accuracy studies perform adequately?

OBJECTIVES: To assess the performance of published search filters in finding diagnostic test accuracy studies. METHODS: Diagnostic test accuracy search filters were identified by searching medline, our own files and by requesting unpublished filters from colleagues. We applied the filters to a case study review of diagnostic test accuracy studies for urinary tract infections (UTI) in young children. The included studies with records in medline formed the gold standard. The performance of the filters in finding those gold standard records was assessed. RESULTS: We identified twenty-three diagnostic test accuracy search filters for use with medline. The case study systematic review of UTI included 179 studies of diagnostic test accuracy, of which 160 were available in medline. The filters showed a wide range of sensitivities (range: 20.6% to 86.9%) and precision (range: 1% to 9.4%). CONCLUSIONS: Our results broadly support those reported in two other studies. The search filters tested do not offer an adequate trade-off between sensitivity and precision to be used to identify studies for systematic reviews. However, there are methods available to explore whether search filters are viable based on an objective statistical analysis of the text and indexing used in records.     

Designing Complexity

This article considers the nature of complexity and design, as well as relationships between the two, and suggests that design may have much potential as an approach to improving human performance in situations seen as complex. It is developed against two backgrounds. The first is a world view that derives from second order cybernetics and radical constructivism. What is particular about this view is that it accepts that our understanding of the world is made by us, regardless of whether it originates in an external reality or not. Indeed, it regards the question of whether an external reality can ever be known by us as essentially undecidable, which is part of its power. In terms of complexity, this leads to the position that we choose the complexity we see in the world. The second is design. Design is a way of behaving that approaches complexity in a different way (and expecting a different type of outcome) than we have conventionally used. Designers work in a way (a conversation with the self via the medium of drawing) that allows them to deal with very complex, ill‐defined and ambiguous situations that would probably be inaccessible using conventional approaches. The outcomes of design are generally novel but can never be argued to be the best solution. Design is necessarily a constructivist, second order cybernetic activity. It is suggested that, as second order cybernetics and radical constructivism give us new insights into the nature of complexity, design gives us a way of acting that comprehends these insights.     

Developing efficient search strategies to identify reports of adverse effects in MEDLINE and EMBASE

OBJECTIVE: This study aimed to assess the performance, in terms of sensitivity and precision, of different approaches to searching MEDLINE and EMBASE to identify studies of adverse effects. METHODS: Five approaches to searching for adverse effects evidence were identified: approach 1, using specified adverse effects; approach 2, using subheadings/qualifiers; approach 3, using text words; approach 4, using indexing terms; approach 5, searching for specific study designs. The sensitivity and precision of these five approaches, and combinations of these approaches, were compared in a case study using a systematic review of the adverse effects of seven anti-epileptic drugs. RESULTS: The most sensitive search strategy in MEDLINE (97.0%) required a combination of terms for specified adverse effects, floating subheadings, and text words for 'adverse effects'. In EMBASE, a combination of terms for specified adverse effects and text words for 'adverse effects' provided the most sensitive search strategy (98.6%). Both these search strategies yielded low precision (2.8%). CONCLUSIONS: A highly sensitive search in either database requires a combination of approaches, and has low precision. This suggests that better reporting and indexing of adverse effects is required and that an effective generic search filter may not yet be feasible.