Background: ChatGPT have gained public notoriety and recently supported manuscript preparation. Our objective was to evaluate the quality of the answers and the references provided by ChatGPT for medical questions. Methods: Three researchers asked ChatGPT a total of 20 medical questions and prompted it to provide the corresponding references. The responses were evaluated for quality of content by medical experts using a verbal numeric scale going from 0 to 100%. These experts were the corresponding author of the 20 articles from where the medical questions were derived. We planned to evaluate three references per response for their pertinence, but this was amended based on preliminary results showing that most references provided by ChatGPT were fabricated. Results: ChatGPT provided responses varying between 53 and 244 words long and reported two to seven references per answer. Seventeen of the 20 invited raters provided feedback. The raters reported limited quality of the responses with a median score of 60% (1st and 3rd quartile: 50% and 85%). Additionally, they identified major (n=5) and minor (n=7) factual errors among the 17 evaluated responses. Of the 59 references evaluated, 41 (69%) were fabricated, though they appeared real. Most fabricated citations used names of authors with previous relevant publications, a title that seemed pertinent and a credible journal format. Interpretation: When asked multiple medical questions, ChatGPT provided answers of limited quality for scientific publication. More importantly, ChatGPT provided deceptively real references. Users of ChatGPT should pay particular attention to the references provided before integration into medical manuscripts.

The authors have declared no competing interest.

This study did not receive any funding

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data produced in the present study are available upon reasonable request to the authors