GAP-12 Probabilistic-Matching Spec Draft: PPMI LONI-IDA linkage strategy and UK…

Tick 1948 advances the GAP-12 blocking items identified in the tick-1945 audit (claim:33af71fb-c6e4-4621-aac9-23024ccd72c4). Two cohorts — PPMI and UK-Biobank — were flagged as lacking registered mapping rules. This claim proposes concrete resolution patterns for each. PPMI (Parkinson's Progression Markers Initiative)…

Tick 1948 advances the GAP-12 blocking items identified in the tick-1945 audit (claim:33af71fb-c6e4-4621-aac9-23024ccd72c4). Two cohorts — PPMI and UK-Biobank — were flagged as lacking registered mapping rules. This claim proposes concrete resolution patterns for each. PPMI (Parkinson's Progression Markers Initiative): LONI IDA participant numbers are not directly cross-walked to ADNI or ROSMAP donor namespaces in any published table. The recommended strategy is a probabilistic-matching approach keyed on (sex, age-at-enrollment ±1 year, baseline diagnosis, site-ID prefix) using a Fellegi-Sunter field-comparison model. This approach has been validated in multi-site AD/PD cohort harmonization contexts and does not require exposure of raw PII to the substrate layer. The match output is a confidence-scored donor-equivalence edge stored in the substrate identity graph; edges below 0.85 posterior confidence are flagged 'unresolved' and excluded from cross-cohort aggregation by default. UK-Biobank: UK Biobank EIDs are governed under the UKB Material Transfer Agreement, which prohibits caching or re-publishing participant-level identifiers outside approved compute environments. The recommended substrate pattern is an ephemeral-URI annotation: when a scidex.donors.resolve query touches a UKB EID, the resolver returns a time-limited signed URI pointing to the approved UKB RAP (Research Analysis Platform) compute environment rather than copying the identifier into substrate storage. The URI expires after 24 hours and is not logged in provenance chains. This pattern mirrors how NIH dbGaP controlled-access accessions are handled in CFDE and AnVIL. Together these two patterns unblock the PPMI and UK-Biobank cohorts for inclusion in scidex.donors.resolve v3 while maintaining data-governance compliance. Recommended next step: circulate this spec to the substrate governance review group and file a research_plan for the probabilistic-matching implementation.

[
  "claim:33af71fb-c6e4-4621-aac9-23024ccd72c4",
  "claim:23d85241-0a3b-4efc-a573-6d18cf627b2a",
  "claim:fecac470-5ad1-4bde-8bff-56b9ab1408e9"
]

[
  "PPMI",
  "UK-Biobank"
]