Results Reporting and Registry-Linked Publications Among Extracorporeal Membrane Oxygenation Studies Registered on ClinicalTrials.gov: A Cross-Sectional Meta-Research Study.

Extracorporeal membrane oxygenation (ECMO) research has expanded rapidly, but how often completed ECMO studies make their results publicly available is not known. This cross-sectional meta-research study examined ECMO study records on ClinicalTrials.gov at a census date of 13 September 2026. A field-scoped query of the registry's application programming interface returned 524 records, of which 493 met prespecified eligibility criteria after duplicate model-assisted screening with every decision checked by the first author. The primary outcome was the proportion of completed studies with a primary completion date at least 12 months before the census date that had summary results posted on the registry. Registry-linked PubMed references were classified by article type. Of the 493 studies, 268 (54.4%) were observational and 471 (95.5%) had a non-industry lead sponsor. In the 184-study 12-month-observable completed cohort, 14 had posted summary results (7.6%, 95% CI 4.6 to 12.4), and one had done so within 12 months of primary completion. Posting was more frequent in interventional than observational studies (17.6% versus 1.7%, risk difference 15.9 percentage points, 95% CI 7.5 to 26.7). Sixty-one studies (33.2%) carried at least one registry-linked PubMed reference, and 60 (32.6%) were linked to an article reporting their results. All four records meeting a post hoc registry-based approximation of applicable clinical trial status had posted results, but this subgroup was too small, and its classification too uncertain, to support any inference about regulation. Summary-results posting was uncommon among completed ECMO studies, a majority of which are observational and therefore outside the scope of United States statutory reporting requirements.