Large language models (LLMs) offer substantial promise for improving health care; however, some risks warrant evaluation and discussion. This study assessed the effectiveness of safeguards in foundational LLMs against malicious instruction into health disinformation chatbots. Five foundational LLMs-OpenAI's GPT-4o, Google's Gemini 1.5 Pro, Anthropic's Claude 3.5 Sonnet, Meta's Llama 3.2-90B Vision, and xAI's Grok Beta-were evaluated via their application programming interfaces (APIs). Each API received system-level instructions to produce incorrect responses to health queries, delivered in a formal, authoritative, convincing, and scientific tone. Ten health questions were posed to each customized chatbot in duplicate. Exploratory analyses assessed the feasibility of creating a customized generative pretrained transformer (GPT) within the OpenAI GPT Store and searched to identify if any publicly accessible GPTs in the store seemed to respond with disinformation. Of the 100 health queries posed across the 5 customized LLM API chatbots, 88 (88%) responses were health disinformation. Four of the 5 chatbots (GPT-4o, Gemini 1.5 Pro, Llama 3.2-90B Vision, and Grok Beta) generated disinformation in 100% (20 of 20) of their responses, whereas Claude 3.5 Sonnet responded with disinformation in 40% (8 of 20). The disinformation included claimed vaccine-autism links, HIV being airborne, cancer-curing diets, sunscreen risks, genetically modified organism conspiracies, attention deficit-hyperactivity disorder and depression myths, garlic replacing antibiotics, and 5G causing infertility. Exploratory analyses further showed that the OpenAI GPT Store could currently be instructed to generate similar disinformation. Overall, LLM APIs and the OpenAI GPT Store were shown to be vulnerable to malicious system-level instructions to covertly create health disinformation chatbots. These findings highlight the urgent need for robust output screening safeguards to ensure public health safety in an era of rapidly evolving technologies.

Tirzepatide reduced weight and improved cardiometabolic risk factors for participants in the SURMOUNT-1 trial. The changes in cardiometabolic risk factors by degree of tirzepatide-induced weight reduction across a wide spectrum of weight loss have not been reported.

Reduction of premature death and adverse cardiovascular outcomes is a key goal in type 2 diabetes management.

In January 2025, the Republican majority in the House of Representatives' Budget Committee offered a list of possible spending reductions to offset revenue losses from proposed tax cuts. In May, the Committee advanced a bill incorporating several reductions on the list. The Committee estimated that the 6 largest potential Medicaid cuts (for example, work requirements for some Medicaid enrollees) would each reduce the federal government's Medicaid outlays by at least $100 billion over 10 years. On the basis of the Committee's estimates of savings; Congressional Budget Office analyses; and peer-reviewed studies of the coverage, financial, and health impacts of past Medicaid expansions and contractions, the authors project the likely effects of each option and of the House bill advanced by the Budget Committee in May. Each option individually would reduce federal Medicaid outlays by between $100 billion and $900 billion over a decade, increase the ranks of the uninsured by between 600 000 and 3 900 000 and the annual number of persons forgoing needed medical care by 129 060 to 838 890, and result in 651 to 12 626 medically preventable deaths annually. Enactment of the House bill advanced in May would increase the number of uninsured persons by 7.6 million and the number of deaths by 16 642 annually, according to a mid-range estimate. These figures exclude harms from lowering provider payments and shrinking benefits, as well as possible repercussions from states increasing taxes or shifting expenditures from other needs to make up for shortfalls in federal Medicaid funding. Policy makers should weigh the likely health and financial harms to patients and providers of reducing Medicaid expenditures against the desirability of tax reductions, which would accrue mostly to wealthy Americans.

Following the success of the ANCHOR (Anal Cancer-HSIL Outcomes Research) trial, the U.S. Department of Health and Human Services recommends anal cancer screening for high-risk persons, particularly men who have sex with men (MSM) with HIV.

Fecal microbiota transplantation (FMT) is recommended for recurrent Clostridioides difficile infection (CDI), but its role in primary CDI is unclear.