A study from Columbia University researchers found that fabricated references are appearing more frequently in biomedical literature, with the measured rate rising sharply from 2023 to 2025. In work led by healthcare AI scientist Maxim Topaz, the team reported an increase from 4 fabricated references per 10,000 papers in 2023 to 51.3 per 10,000 papers by the end of 2025. The results, published in the Proceedings of the National Academy of Sciences, quantified the scale of the issue across multiple disciplines, including biomedical research as well as physics, computer science, materials science, engineering, and chemistry. The researchers analyzed 21.6 million references from 500,000 studies indexed in OpenAlex between January 2023 and March 31, 2026, identifying 1,135 likely fabricated references across 619 papers. Methodologically, the team compared reference entries in papers against DOI-linked records and then cross-checked unmatched titles using multiple sources, with a large language model used to reduce false positives driven by formatting differences. The paper emphasizes the need for publishers and the research community to remove invalid citations to protect downstream research and clinical decision-making. While fabricated references represented a small share of all references evaluated, the paper frames the acceleration as a warning sign for scholarly quality control as publication volumes and AI-enabled generation of text expand.