One pre-ACR Convergence 2026 baseline. ChatGPT, Claude, Gemini and Perplexity,
each with web search, answered the same questions once each on 30 October 2026,
with a US rheumatologist persona applied. The answers are AI answers.
AI Visibility — the share of all 1,816 answers to open questions that name
a therapy, by its molecule name or any in-scope brand, matched word for word
against a frozen list of 25 molecules and 43 brands. Any mention counts,
including cautionary or historical mentions. Names that appear only in a link
are not counted.
Named first — the first scored therapy named in an answer, over the 1,496
answers that name at least one. Order of mention, not preference. It is
reported for the four AI systems combined, for the ten therapies named first
most often.
Head-to-head verdicts — an AI judge (gpt-4.1-mini) read each of the 960
answers to comparative questions and scored each therapy the question names as
preferred, equal, inferior or not compared. A therapy is favoured only when it
was preferred, its comparator inferior, and the judge noted no condition.
Conditional verdicts — where the answer makes the choice depend on the patient
or the clinical context — are shown separately and never counted as favoured.
Other covers answers where only one therapy was scored, no clear preference
was expressed, or a therapy was not mentioned. Eight complex questions were
reviewed by an analyst instead and are not in the figures.
Patient profiles — a comparative answer belongs to a profile when its
question is framed around that patient. Profiles overlap, so their figures are
never added together. Four profiles are published, and within each only the
therapies compared at least 8 times.
Small bases — the base is stated wherever a figure rests on fewer than 30
answers, and a figure resting on fewer than 10 is marked Small base. Many
question-type rows of a single pair rest on 4 answers: one question, answered
once by each AI system.
What the explorer offers — the head-to-head explorer offers the 42 pairs
compared at least 8 times. A therapy's total head-to-head
verdicts, and the JAK question-type view, also count pairs compared fewer
times, so they are larger than the sum of the pairs the explorer shows.
What this does not show
Not efficacy, safety or clinical preference, and not a recommendation. A
verdict describes what one AI answer favoured for one question; pooled
verdicts do not establish clinical superiority, and no net or overall score is
computed. No AI system is ranked or scored: differences between systems are
mostly how many therapies an answer names. Therapies outside the scored list
are not ranked and are not zero. One collection date, before ACR Convergence
2026; web-search answers change over time, and this benchmark will be
re-measured after ACR.