This paper provides the arguments for prospective registration of diagnostic test accuracy (DTA) studies in public databases. The authors do not advocate the creation of a specific registry for DTA studies, but registration is recommended in any available known public registry.  A list of possible registries is provided in Table 1 of the paper.

The authors propose a modified version of the WHO trial registration data set (Table 2 in the paper) which specifies the fields that would be needed for registry records to capture the key elements of a DTA study. 

Using their modified version of the WHO trial registration data set, the authors evaluated the reported information for the 30 most recently registered DTA studies in the WHO ICTRP in November 2016.  This small analysis provides some information for searchers who are searching for DTA studies in ICTRP.   In the sample of thirty studies, 90% reported that the study was a DTA study in the title of the record, 97% reported the target condition and 100% reported the index test.

The authors call on trial registries to ensure informative data are included in registry records to enhance identification.  They also call on journal editors to encourage DTA study registration prior to publication.

The authors compared the information available in clinical study reports and in publicly accessible sources (journal articles, registry reports) included in 16 HTA reports for drugs prepared in IQWiG. They assessed the completeness of information on patient-relevant benefit (e.g. symptom relief, health related quality of life) and harm (adverse effects) outcomes reported in each document type. Clinical study reports provided complete information of all outcomes on a higher proportion (86%) than publicly accessible sources (39%). They also provided more information on harms (87% versus 43 %). The authors conclude that clinical study reports should be made publicly available for the benefit of unbiased trial evaluation and informed decision-making in health care.

Research has shown that most systematic reviews of adverse effects rely solely on searches of MEDLINE, even though it is unlikely to be a comprehensive source on adverse effects information. The authors aimed to identify and summarize studies that had evaluated sources of information on adverse effects. No date or language restrictions were applied when searching for studies. The results indicated that Embase, Derwent Drug File, MEDLINE and industry submissions might be the sources of the largest number of relevant references for adverse effects information. In addition, they concluded that searching a wide range of sources might be a useful approach when conducting a thorough search.

The authors assessed the impact of including unpublished data on adverse effects in systematic reviews. They carried out a systematic review of methodological evaluations comparing the quantitative reporting of adverse effects data between published and unpublished sources. The key finding was that unpublished studies could provide additional adverse effects information. However, there was insufficient data to conclude whether including unpublished studies would have major impact on the results of meta-analyses.