Authors self-disclosed use of artificial intelligence in research submissions to 49 biomedical journals: A cross-sectional study

OBJECTIVE: To analyze the frequency of self-disclosed use of AI in research manuscripts submitted to 49 biomedical journals and to identify types of AI tools used, the tasks they assisted with, and factors associated with disclosure. DESIGN: Cross-sectional study. SETTING: 49 biomedical journals published by BMJ Group. PARTICIPANTS: Submitting authors of 25,114 empirical research manuscripts including systematic reviews and meta-analyses, submitted between 8 April 2024 and 6 November 2024. MAIN OUTCOME MEASURES: Prevalence of manuscripts with self-disclosed use of AI, types of AI tools used, the tasks they assisted with and factors associated with disclosure. RESULTS: There was a total of 25,114 eligible submissions: Asia (13,505; 53.8%), Europe (6,523; 26.0%), North America (2,795; 11.1%), Africa (1,196; 4.8%), Oceania (708; 2.8%), and South America (387; 1.5%). A total of 1,431 submissions (5.7%) disclosed the use of AI. The most frequently reported AI tools used were Generative AI Chatbots (812/1431; 56.7%) and writing assistants (182; 12.7%). The majority of authors who disclosed AI use reported using it to improve the quality of their writing (1,248/1,431; 87%). Additionally, translation (107; 7.5%), generating data and output (87, 6.1%), literature searches (49; 3.4%), analyzing data (31; 2.2%), image processing or analysis (49; 3.4%), code writing (15; 1.0%), and managing references (14; 0.9%) were mentioned as tasks AI assisted with. Authors from South America (OR=1.75; 95%-CI: 1.22-2.49) and Europe (OR=1.28; 95%-CI: 1.14-1.45) were significantly more likely to disclose AI use than those from Asia. Conversely, each additional author reduced disclosure odds by 1% (OR=0.99, 95%-CI: 0.97-0.99). Acceptance rate, impact factor, type of journal, and peer review model) were not associated with AI use disclosure. CONCLUSIONS: We found that only a small proportion (5.7%) of submitting authors disclosed AI use, which is substantially lower than proportions reported in surveys. Improving the quality of writing was the primarily task AI assisted with and AI Chatbots were the most commonly disclosed tool. Authors may be uncertain about what AI use requires disclosure or may be hesitant to declare it.