Hospital Community Health Needs Assessment (CHNA) Findings: an open dataset (Dark Health Data)

Dark Health Data: U.S. non-profit hospital Community Health Needs Assessments (CHNAs, IRC 501(r)(3)), extracted via Claude claude-haiku-4-5 with a verification layer (grounding, neurosymbolic constraints, ensemble, conformal gate). This release (v0.4.3) is an expanded national crawl: 656,194 records from 2,069 source documents naming 6,437 hospitals across 51 states (2-letter normalized): 518,584 identified community health needs, 137,610 implementation strategies. Approaching the full ~2,900 non-profit-hospital universe; later versions add the remaining tail. Every record carries full provenance and a quality/trust score; nothing is imputed or dropped. AI-extracted, not yet independently validated — preliminary; filter on the trust score. Public-record documents only; no PHI. Code (Apache-2.0): github.com/sanjaybasu/dark-health-data. CC0-1.0.