ClinicalKey AI vs OpenEvidence (2026)
Both put a language model between a clinician and the literature, grounded in different libraries. ClinicalKey AI answers from Elsevier's own licensed content, refreshed daily: reference texts such as Braunwald's Heart Disease, society guidelines, and full text journals including The Lancet, the New England Journal of Medicine and JAMA. Elsevier names OpenAI and Anthropic as its model providers, under zero retention contracts. OpenEvidence answers from more than 300 journals plus FDA and CDC sources, free to verified US and Canadian clinicians and paid for by advertising inside the product. The difference is who pays and who checked the answers. Elsevier sells ClinicalKey AI to institutions and published its own evaluation. OpenEvidence costs a clinician nothing, and outside researchers have published studies of it.
- A company run evaluation of 426 answers by 41 paid physicians and pharmacists: 95.5 percent rated correct, and 2 rated as potential harm.
- Named model providers, OpenAI and Anthropic, under zero retention contracts.
- SMART on FHIR sign on inside the record, an API, and links to an institution's own full text holdings.
- Free use for verified clinicians, where ClinicalKey AI offers a 90 day trial and quotes institutions through sales.
- Independent peer reviewed studies, including 100 percent citation accuracy across 999 citations on spine guideline questions.
- A model family that trades speed for depth, from direct answers to structured reports.
This comparison is published by AI Health Index, an independent research platform that compares healthcare AI vendors objectively. ClinicalKey AI and OpenEvidence are each graded against the same capability taxonomy, from each vendor's own public materials and the regulatory record, under the AI Health Index verification standard. No vendor pays for placement, and no vendor has reviewed this page. How this evidence is graded
Plain facts
| Fact | ClinicalKey AI | OpenEvidence |
|---|---|---|
| Primary category | Clinical Reference & Evidence | Clinical Reference & Evidence |
| Founded | Not recorded | 2021 |
| Headquarters | New York, New York | Miami, Florida |
| Website | elsevier.com | openevidence.com |
Side by Side
Select any grade to read the note behind it.
Product updates
The latest logged changes from each vendor, newest first, each linked to its source.
ClinicalKey AI
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Product / capability
Elsevier launched ClinicalKey Nursing AI, a conversational clinical decision support tool built specifically for nurses.
Source
OpenEvidence
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Product / capability
OpenEvidence added the American Society of Addiction Medicine's clinical guidelines, guidance and implementation resources to the content behind its answers.
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Product / capability
OpenEvidence launched Patient Take-Homes, a new feature allowing clinicians to optionally turn AI-generated answers into educational materials for their patients.
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Clinical evidence
A systematic review published in npj Digital Medicine evaluated 11 studies assessing OpenEvidence's clinical question-answering capabilities.
Source
Each vendor in one paragraph
Written to be quoted whole. Each paragraph opens the AI Health Index profile of the vendor: what the product is, who buys it and what it does.
ClinicalKey AI is a generative clinical decision support layer built on ClinicalKey, Elsevier Health's point of care content platform. It launched in February 2024 and was expanded in February 2026 with full text journal content and new features. Elsevier's wider portfolio spans scientific publishing and research analytics.
Source: AI Health Index, September 2026
AI medical search and clinical decision support used at the point of care, free to verified United States and Canadian clinicians and funded by pharmaceutical and medical device advertising shown inside the product, with enterprise deployments embedded in the electronic health record at named health systems. The published model family is Osler for direct answers in seconds, Sackett for a more thorough survey.
Source: AI Health Index, September 2026
Questions buyers ask
How do ClinicalKey AI and OpenEvidence work with the EHR?
For ClinicalKey AI, the product page states SMART on FHIR single sign on for access inside the EHR, an API so the product can be integrated into tools beyond the EHR, and link resolver support connecting to an institution's own full text holdings.
With OpenEvidence, the first party evidence is recent. On 22 September 2026 the company and the University of Texas Medical Branch announced a collaboration putting cited clinical evidence inside the electronic health record, live at UTMB since March 2026, with adoption reported as growing since launch. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 29, 2026. No vendor pays for placement.
How are ClinicalKey AI and OpenEvidence priced and sold?
In ClinicalKey AI's case, clinicians and residents can try the product free for 90 days, medical students in the United States and Canada get one year of full access free, and institutions are directed to request institutional access or speak with an Elsevier sales representative.
For OpenEvidence, the named health system collaborations announced through 2026 carry no commercial terms. It is also not stated whether free individual use by a health system's clinicians creates any institutional obligation before a contract exists. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 29, 2026. No vendor pays for placement.
How do ClinicalKey AI and OpenEvidence handle patient data?
The ClinicalKey AI FAQ adds that all user data is encrypted in transit and at rest, that access is limited to authorized personnel under pseudonymization for product support only, and that no access is granted to cloud providers or third party AI partners for training. Users can save, search, share or remove past queries in a privacy panel.
In OpenEvidence's case, the scope is narrower than it first looks. The exclusion is drawn around protected health information, not around everything a clinician types. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 29, 2026. No vendor pays for placement.
Which settings and specialties do ClinicalKey AI and OpenEvidence cover?
For ClinicalKey AI, the corpus spans cardiology, internal medicine and pediatrics reference texts, society guidelines covering cardiology, endocrinology, emergency medicine, chest medicine and oncology, drug information, and full text journals, and responses can take a patient's age, comorbidities and medications into account when the clinician supplies them.
With OpenEvidence, the product now covers the consultation, the encounter through Visits, and patient contact through the Dialer, with an education platform carrying continuing education and maintenance of certification credit added on 28 July 2026. From the AI Health Index, drawn from each vendor's own published materials and the regulatory record, verified September 29, 2026. No vendor pays for placement.
Related comparisons
Other published head to head assessments involving these vendors or their closest peers.
Both records were reviewed on this site in September 2026. Neither publishes an institutional price; OpenEvidence is free to clinicians and funded by advertising. All seven authors of ClinicalKey AI's evaluation are current or former Elsevier employees.
Ask both how an interpretive error is caught when every citation beneath it is real.