Map a literature search
Search PubMed, then watch up to 500 papers arrange themselves by what they talk about. Similar papers gather into constellations; the brightest stars are randomized trials and systematic reviews. See at a glance where the evidence is strong, where it is thin, and what is growing.
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PubMed search
Reading papers…
Designs come from PubMed publication types and, when those are missing, from words in the title and abstract. This maps what your query returned, not everything published: a gap here is a question to check, not a conclusion.