{
  "abstract": "Background\n\nAbdominal surgery poses unique challenges to the conduct of randomized clinical trials (RCTs). However, trial discontinuation, non-publication, and selective reporting may result in an incomplete picture of the available evidence base. This study assessed the trajectories of RCTs in abdominal surgery from trial registration to the publication and reporting of results.Methods\n\nRCTs in adult abdominal surgery were identified through a systematic search of ClinicalTrials.gov, the EU Clinical Trials Register, and the International Clinical Trials Registry Platform from database inception until 31 January 2018. Corresponding trial publications were identified by searching PubMed, Google Scholar, and Google. Selective reporting was evaluated by examining consistency of primary endpoints and reported P values in published trials.Results\n\nAfter screening 2654 registry records, 295 trials were deemed eligible for inclusion. Among these, 160 (54%) were reported as completed in trial registries. An elective non-cancer trial population was associated with lower odds of non-completion (odds ratio (OR) 0.46; 95% c.i. 0.27 to 0.78), whereas trials with no reported funding had higher odds of non-completion compared with funded trials (OR 2.05; 95% c.i. 1.16 to 3.66). Among completed trials, a corresponding publication was identified for 119 trials (74%). Completed superiority trials with added or modified primary endpoints were more likely to report P values < 0.050 than primary endpoint-unmodified trials (OR 4.28; 95% c.i. 2.23 to 8.22).Conclusion\n\nNearly half of registered trials are not reported as completed, and a significant proportion of completed trials are not published. Among published trials, discrepancies between registered and published primary outcomes are common. This is consistent with possible selective outcome reporting and evidentiary bias in abdominal surgery, with implications for both guidelines and meta-analytical work.",
  "abstract_shown": true,
  "affiliations": [
    "Department of General Surgery, Division of Visceral Surgery, Medical University of Vienna, Vienna, Austria.",
    "Department of Surgery, Clarunis University Digestive Health Care Center Basel, University Hospital Basel, Basel, Switzerland.",
    "Department of Surgery, Division of Visceral Surgery, Medical University of Zurich, Zurich, Switzerland.",
    "Department of Surgery, Groene Hart Hospital, Gouda, the Netherlands.",
    "Department of General Surgery, Hôpital Fribourgeois, Fribourg, Switzerland.",
    "Division of Radiation Oncology, Department of Gastrointestinal Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.",
    "Usher Institute, The University of Edinburgh, Edinburgh, UK."
  ],
  "article_type": "review article",
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Klaudia Narbekovas"
    },
    {
      "affs": [
        1
      ],
      "name": "Christoph Kuemmerli"
    },
    {
      "affs": [
        2
      ],
      "name": "Sandro Huegli"
    },
    {
      "affs": [
        3
      ],
      "name": "Jasper P Sijberden",
      "orcid": "0000-0002-1186-5320"
    },
    {
      "affs": [
        4
      ],
      "name": "Lukas W Widmer"
    },
    {
      "affs": [
        0
      ],
      "name": "Oliver Strobel"
    },
    {
      "affs": [
        0
      ],
      "name": "Max F Stauffer"
    },
    {
      "affs": [
        5
      ],
      "name": "Ethan B Ludmir"
    },
    {
      "affs": [
        0,
        6
      ],
      "name": "Carl-Stephan Leonhardt",
      "orcid": "0009-0001-7179-9580"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f4cp0tkrsfk6m.bib",
  "cited_by": 0,
  "doi": "10.1093/bjsopen/zrag160",
  "fulltext_url": "https://europepmc.org/articles/PMC13692691",
  "id": "f4cp0tkrsfk6m",
  "issns": [
    "2474-9842"
  ],
  "landing_url": "https://europepmc.org/article/MED/42925089",
  "language": "eng",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1804|Meta-analysis and systematic reviews"
    ]
  ],
  "openalex": "W7223299382",
  "pdf_url": "https://europepmc.org/articles/PMC13692691?pdf=render",
  "pmcid": "PMC13692691",
  "pmid": "42925089",
  "published": "2026-09-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/f4cp0tkrsfk6m.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:02Z",
      "native_id": "MED:42925089",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42925089"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "journal-openalex:2746|Enhanced Recovery After Surgery",
      "subfield": "surgery"
    }
  ],
  "title": "Completion, publication, and outcome reporting of registered randomized trials in abdominal surgery: registry-based cohort study.",
  "title_text": "Completion, publication, and outcome reporting of registered randomized trials in abdominal surgery: registry-based cohort study.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:21:02Z",
  "url": "https://research.draconitic.com/paper/f4cp0tkrsfk6m",
  "venue": "BJS open",
  "versions": []
}