Open Questions

Decisions on the draft rules

1. Rule 3: whose answers and set members does a replaced concept bring? This is the main decision. The draft follows the replacement; the alternatives are the referenced concept, the union of both, or step by step.
2. Rule 4: how does OCL record a mapping re-pointed to a replacement? An expansion's members are concept and mapping versions, and a mapping from CIEL:161557 to PIH:1065 isn't a version of any mapping in any source. Either keep CIEL's mapping and the SAME-AS mapping, and have the export and the OpenMRS import apply the replacement; or have OCL generate the re-pointed mapping as part of the expansion.
3. Rule 1: does the direction of a SAME-AS mapping matter (PIH → CIEL or CIEL → PIH)? Draft: no.
4. Rule 1: does a chain count? For example, a PIH concept and a CIEL concept that are each SAME-AS the same SNOMED CT term. Draft: no.
5. Rule 5: does the reference stay as written, or is it rewritten to the replacement? Draft: it stays.
6. Rule 6: when someone adds a concept that has an equivalent, does OCL allow it and tell them, offer the replacement, block it, or allow it silently? Draft: allow it and tell them.

Cases the five scenarios don't cover

7. A missing equivalency (a possible sixth scenario). PIH:1100 and CIEL:1100 are both "Daily or almost daily", but no SAME-AS mapping links them. Under the rules they aren't equivalent, so a dictionary could contain both. Do we fix this in the content (add the mapping), or should OCL help find such pairs?
8. Two equivalents in one source (a tie). Draft: keep the original concept and flag it.
9. Three or more ranked sources, such as a custom source, PIH and CIEL. Because chains don't count, a custom concept and a PIH concept that both map to the same CIEL concept could both end up in the expansion.
10. Keeping a lower-ranked concept on purpose: should a reference be able to opt out of substitution?
11. Exclusions: does excluding CIEL:1065 also exclude PIH:1065?
12. A replaced concept's other mappings, such as CIEL's mappings to SNOMED CT and ICD-10: do any of them carry over to the replacement?
13. A concept from a source not on the ranked list, reached by a cascade.

Broader questions

14. What's the benefit for an organization that already manages its dictionary as a source, such as PIH, of switching to a collection? Background has a partial answer.
15. The questions for the community on Background: is explicit source precedence right, and is an ordered list the right mechanism? When would automatic substitution via SAME-AS mappings be undesirable? Are there other approaches?