Fate of Clinical Research Studies after Ethical Approval – Follow-Up of Study Protocols until PublicationReport as inadecuate




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Background

Many clinical studies are ultimately not fully published in peer-reviewed journals. Underreporting of clinical research is wasteful and can result in biased estimates of treatment effect or harm, leading to recommendations that are inappropriate or even dangerous.

Methods

We assembled a cohort of clinical studies approved 2000–2002 by the Research Ethics Committee of the University of Freiburg, Germany. Published full articles were searched in electronic databases and investigators contacted. Data on study characteristics were extracted from protocols and corresponding publications. We characterized the cohort, quantified its publication outcome and compared protocols and publications for selected aspects.

Results

Of 917 approved studies, 807 were started and 110 were not, either locally or as a whole. Of the started studies, 576 71% were completed according to protocol, 128 16% discontinued and 42 5% are still ongoing; for 61 8% there was no information about their course. We identified 782 full publications corresponding to 419 of the 807 initiated studies; the publication proportion was 52% 95% CI: 0.48–0.55. Study design was not significantly associated with subsequent publication. Multicentre status, international collaboration, large sample size and commercial or non-commercial funding were positively associated with subsequent publication. Commercial funding was mentioned in 203 48% protocols and in 205 49% of the publications. In most published studies 339; 81% this information corresponded between protocol and publication. Most studies were published in English 367; 88%; some in German 25; 6% or both languages 27; 6%. The local investigators were listed as co-authors in the publications corresponding to 259 62% studies.

Conclusion

Half of the clinical research conducted at a large German university medical centre remains unpublished; future research is built on an incomplete database. Research resources are likely wasted as neither health care professionals nor patients nor policy makers can use the results when making decisions.



Author: Anette Blümle , Joerg J. Meerpohl, Martin Schumacher, Erik von Elm

Source: http://plos.srce.hr/



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