10/23/2026
Of the 68 published clinical trials of large language model interventions identified in this BMJ systematic review, 43 tested patient-facing health education and 39 enrolled patients as the participants. These are the trials where a confident wrong answer reaches someone with no training to catch it. Yet among the 44 randomised trials, 19% described how harms would be assessed and 26% reported any harms at all. Among the 42 chatbot trials, 31% checked the outputs for harmful content, and 41% of randomised trials included an error analysis. The people on the receiving end were also rarely in the room when the trials were designed. Patient and public involvement was reported in 2% of randomised trials under CONSORT and 7% of all trials under TRIPOD-LLM. Patients helped develop the prompts in 14% of chatbot trials and took part in evaluating the outputs in 25%. A trial can clear ethics review and reach a journal while the only patient role is to be the subject.
The trials also come from a narrow slice of the world. Corresponding authors were based in Asia for 36 of the 68 reports and in North America for 20. Europe accounted for 10. Africa and Oceania had one trial each, and South America had none. Recruitment sites followed the same pattern: one published trial recruited in Africa, none in South America. When we tried to compare reporting completeness by region, Europe, Africa and Oceania had to be pooled into a single group of 12 trials, so the paper can say nothing about how LLM trials are reported across most of the world. The models under test, mostly OpenAI’s GPT family, are already being used by patients on every continent.
https://www.bmj.com/content/395/bmj-2026-100855