hardDesignScenarioMidSeniorStaff
How do you match patient records across systems when there is no shared identifier?
Patient matching across healthcare systems uses deterministic rules, probabilistic linkage and human review to connect records without a shared identifier. Blocking, thresholding and reversible links matter because false merges are clinically riskier than false splits. It also connects record linkage to the point an interviewer is testing.
6 min readUpdated 2026-08-15
Answer
Short answer
Match patient records without a shared identifier by generating candidate pairs through blocking, comparing demographics and identifiers, and scoring agreement with deterministic rules or probabilistic linkage. Use match, no-match and human-review bands, bias thresholds against false merges, and keep source records immutable so a bad link can be reversed with its evidence trail intact.
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Likely follow-ups
- How would you measure match quality when you have no labelled ground truth to start from?
- A merge is retracted six months later. What has to happen to the orders, results and claims already filed against the merged identifier?
- How does adding a second country's patient population change your field weights?
- Where would you draw the line between an automated merge and one that requires a human, and who owns that threshold?
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