@phdthesis{Riemer2022,
  author    = {Riemer, Manuel},
  title     = {Analysen zur Studienregistrierung und selektiven Endpunktberichterstattung in 585 klinischen Studien, die Medikamente zur PONV Prophylaxe untersuchten},
  doi       = {10.25972/OPUS-28769},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287699},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Im Jahr 2017, 13 Jahre nachdem das ICMJE die prospektive Protokollregistrierung zur Notwendigkeit f{\"u}r zuverl{\"a}ssige klinische Studien erkl{\"a}rt hat, ist die H{\"a}ufigkeit und Qualit{\"a}t der Studienregistrierung im Bereich der PONV-Forschung sehr gering. F{\"u}r nur ein F{\"u}nftel der seit dem Jahr 2004 publizierten klinischen Studien, die in den 2020 ver{\"o}ffentlichten PONV Cochrane Review aufgenommen wurden, wurden Studienprotokolle registriert. Von diesen waren fast zwei Drittel retrospektiv registriert. Schlussendlich konnten weniger als 50\% der prospektiv registrierten Studien als frei von Bias bei der selektiven Endpunktberichterstattung identifiziert werden. Dies ist ein alarmierendes Defizit. Diese Arbeit zeigt auch, dass registrierte Studien im Allgemeinen h{\"a}ufiger mit einem niedrigen Gesamtbiasrisiko beurteilt wurden. Dies legt die Studienregistrierung als Qualit{\"a}tskriterium f{\"u}r RCTs in der klinischen PONV-Forschung nahe. Bias durch selektive Endpunktberichterstattung verringert die Vertrauensw{\"u}rdigkeit von Studienergebnissen. Wissenschaftler*innen und Kliniker*innen sollten sich dar{\"u}ber im Klaren sein, dass nur die Adh{\"a}renz bez{\"u}glich einer ad{\"a}quaten Protokollregistrierung und die transparente Berichterstattung {\"u}ber vordefinierte Endpunkte, unabh{\"a}ngig von Richtung und Bedeutung deren Ergebnisse, letztlich die Evidenz der PONV-Forschung in der Zukunft st{\"a}rken kann.},
  subject      = {Bias},
  language  = {de}
}
@article{RiemerKrankeHelfetal.2021,
  author    = {Riemer, Manuel and Kranke, Peter and Helf, Antonia and Mayer, Debora and Popp, Maria and Schlesinger, Tobias and Meybohm, Patrick and Weibel, Stephanie},
  title     = {Trial registration and selective outcome reporting in 585 clinical trials investigating drugs for prevention of postoperative nausea and vomiting},
  series = {BMC Anesthesiology},
  volume    = {21},
  journal   = {BMC Anesthesiology},
  doi       = {10.1186/s12871-021-01464-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265518},
  year      = {2021},
  abstract  = {Background: Selective outcome reporting in clinical trials introduces bias in the body of evidence distorting clinical decision making. Trial registration aims to prevent this bias and is suggested by the International Committee of Medical Journal Editors (ICMJE) since 2004. Methods: The 585 randomized controlled trials (RCTs) published between 1965 and 2017 that were included in a recently published Cochrane review on antiemetic drugs for prevention of postoperative nausea and vomiting were selected. In a retrospective study, we assessed trial registration and selective outcome reporting by comparing study publications with their registered protocols according to the 'Cochrane Risk of bias' assessment tool 1.0. Results: In the Cochrane review, the first study which referred to a registered trial protocol was published in 2004. Of all 585 trials included in the Cochrane review, 334 RCTs were published in 2004 or later, of which only 22\% (75/334) were registered. Among the registered trials, 36\% (27/75) were pro- and 64\% (48/75) were retrospectively registered. 41\% (11/27) of the prospectively registered trials were free of selective outcome reporting bias, 22\% (6/27) were incompletely registered and assessed as unclear risk, and 37\% (10/27) were assessed as high risk. Major outcome discrepancies between registered and published high risk trials were a change from the registered primary to a published secondary outcome (32\%), a new primary outcome (26\%), and different outcome assessment times (26\%). Among trials with high risk of selective outcome reporting 80\% favoured at least one statistically significant result. Registered trials were assessed more often as 'overall low risk of bias' compared to non-registered trials (64\% vs 28\%). Conclusions: In 2017, 13 years after the ICMJE declared prospective protocol registration a necessity for reliable clinical studies, the frequency and quality of trial registration in the field of PONV is very poor. Selective outcome reporting reduces trustworthiness in findings of clinical trials. Investigators and clinicians should be aware that only following a properly registered protocol and transparently reporting of predefined outcomes, regardless of the direction and significance of the result, will ultimately strengthen the body of evidence in the field of PONV research in the future.},
  language  = {en}
}