{
  "version": "1.0",
  "frozen_at": "2026-09-19",
  "basis": "Contextual reading of 30 pilot explanations before reviewing the main sample. Pilot seed 20260918. Main sample drawn independently from the full eligible terminated population; two IDs overlap.",
  "unit": "One registered terminated trial, identified by NCT ID; multiple explicit reasons allowed.",
  "denominator": "All 400 sampled terminated records, including records with missing, unclear or conflicting explanations.",
  "labels": {
    "recruitment": "Explicit slow/insufficient enrollment, inability to recruit or find eligible participants. Low disease incidence is coded here when explicitly linked to accrual.",
    "efficacy": "Explicit lack of efficacy, futility, failure to meet an efficacy endpoint or insufficient observed activity. Do not infer from a sponsor decision or a reference to a statistical analysis without its result.",
    "safety": "Explicit safety concern, toxicity, adverse events or safety-driven stopping. Negated safety concerns do not qualify. An ambiguous combined benefit-risk statement is unclear unless the safety component is explicit.",
    "funding": "Explicit insufficient funding, financial support or study cost constraints. Do not infer funding from commercial decisions alone.",
    "supply": "Explicit unavailable intervention, loss of manufacturer supply, production or product-quality problem affecting supply.",
    "strategy": "Explicit business, commercial, portfolio or development-strategy change, including prioritization and sponsor closure. Does not by itself imply scientific failure.",
    "sponsor_unspecified": "Sponsor/company decision without a stated underlying reason; retain separately from explicit strategy. Do not add this label merely because a sponsor carried out a decision already explained by another label.",
    "operations": "Explicit administrative, logistical, regulatory, design/power or staffing problems. Pandemic disruption qualifies when it stopped operations; low accrual is recruitment. Do not infer recruitment from underpower alone.",
    "external": "Explicit external scientific evidence, changed standard of care, lack of continuing clinical need or changes to treatment recommendations. Do not conflate with failure measured within this trial.",
    "benefit": "Explicit stopping for demonstrated therapeutic efficacy/benefit. Meeting enrollment targets or study objectives is not sufficient.",
    "other": "A specific reason that does not fit another category, with the rationale retained.",
    "unclear": "Absent explanation or no interpretable underlying reason. Rationale distinguishes missing text from a nonspecific explanation. May accompany other labels when an additional stated reason is ambiguous.",
    "status_conflict": "Explanation explicitly states planned completion, successful achievement of study objectives or that study never started, despite TERMINATED status. Preserve original status; flag rather than adjudicate it away."
  },
  "rules": [
    "Read each explanation in full, respecting negation and references to other trials.",
    "Do not infer causal mechanisms from title, phase, enrollment or sponsor identity.",
    "When distinct reasons are explicitly reported, retain all applicable labels; percentages may sum above 100%.",
    "Code direct facts conservatively. Mark uncertainty for missing/nonspecific explanations, ambiguous attribution or status conflicts and recheck these records.",
    "The assessment is by one AI assistant with a repeated review, not independent human adjudication. Do not claim inter-rater agreement or human validation.",
    "Wilson intervals describe sampling uncertainty only, not registry coverage, reporting bias or coding error."
  ]
}