Results Reporting and Registry-Linked Publications Among Extracorporeal Membrane Oxygenation Studies Registered on...

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.