Master Patient Index projects that ship in one quarter typically add cleanup work for the next twelve months. Understanding what that cleanup involves shapes both the initial project scope and the ongoing operational plan.
Phase 1: Initial load (weeks 1-4)
Existing patient records land in the MPI. Load includes: identifiers (SSN, MRN, insurance IDs), demographics (FHIR Patient profile shape), and initial matching pass. Expect 15-30% duplicate candidates on first pass in most health systems.
Phase 2: Merge queue processing (weeks 4-16)
HIM analysts work through the merge queue, confirming or rejecting each candidate. Real per-merge review takes 3-10 minutes; queue depth determines throughput.
Phase 3: Chart tail cleanup (months 4-12)
Even after initial merges, ~2-5% of charts have residual issues: name variations, address history conflicts, deceased-but-active flags. Ongoing detection runs catch these; HIM reviews them as they surface.
Chart cleanup patterns
1. Nightly duplicate detection. Automated scoring identifies new candidate pairs. Threshold-gated auto-merge for high-confidence; manual review for low. 2. Weekly demographic drift review. Patients whose demographics changed significantly since last visit → confirm identity or flag for review. 3. Monthly death registry reconciliation. State registry updates flag deceased patients; MPI updates match status. 4. Quarterly split audit. Detect patients whose single chart split into two (usually clinical vs administrative mistake).
Metrics that matter over time
| Metric | Target after year 1 |
|---|---|
| Duplicate rate (new detections/quarter) | <0.5% |
| Auto-merge accuracy | >98% |
| Manual review queue turnaround | <10 days |
| Death registry lag | <30 days |
Vendor tooling investment
Verato Universal Identity, NextGate, and Aidbox MDM all support the merge queue and manual review workflows. Open alternatives like MITRE FRIL work for the initial matching but require custom review UIs.
MPI is a multi-year operational commitment, not a one-time deployment. Budget the ongoing HIM time; it's not optional.