Backfill `page_or_section` on the existing research evidence rows

[matentzn]

The medic-research-curation skill extracts page hints from the .citations.md files and writes
page_or_section on every evidence row it produces. Every research file we have predates that
change: 0 of the 35 kb/research/<MONDO>.yaml files contain the field, across all 164 evidence
references.

page_or_section is what turns a bare PMID into a locatable claim — it is the difference between
"this paper supports the association" and "this paper supports it here". Without it the research
axis is the only evidence surface in MeDIC where a reader cannot get from the record to the
supporting text without re-reading the whole reference. Going forward the skill fills it; the
existing rows will stay empty unless something backfills them or every disease file is re-curated.

The open question is which. A non-LLM backfill script would scan the cached .citations.md files,
match each existing evidence row by reference_title / reference, and lift the page hint where one
exists — cheap, deterministic, and it touches nothing else in the record. The alternative is to leave
the rows alone and let coverage fill in as diseases are re-curated, which costs nothing now but
leaves the field permanently uneven.

Coverage will be uneven either way: Falcon citations carry page hints reliably, Perplexity
citations rarely do, and the bulk of the current 35 files are Perplexity-sourced. A backfill run on
scripts/backfill_research_pages.py in 2026-05 returned 0 hits for exactly that reason. If the
Falcon share of the corpus is still small, the script is not worth writing until after the next
research batch lands.

Examples

$ ls kb/research/*.yaml | wc -l
35
$ grep -l "page_or_section" kb/research/*.yaml | wc -l
0

Related

• Expand the research axis with ClinicalTrials.gov and systematic PubMed #32 — expands the research axis with ClinicalTrials.gov and systematic PubMed. Trial records carry
  their own locators, so anything ingested there arrives with the field populated; this issue is only
  about the deep-research backlog.
• .claude/skills/medic-research-curation/SKILL.md — the emitter for new rows.
• scripts/backfill_research_pages.py — the existing backfill script, previously a no-op.