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sct dmwb

Read NHS Data Migration Workbench (DMWB) .mdb (Microsoft Access) files via the pure-Rust jetdb reader - no MS Access, no mdbtools. Optional feature: build with --features dmwb.

The goal is to understand the maps DMWB carries that are not in standard SNOMED RF2 - chiefly the Read v2 cross-maps (Read v2 was retired in 2020). The ICD-10 / OPCS-4 / CTV3 maps and concept history that DMWB also bundles are already available from the RF2 sct downloads via sct ndjson --refsets all, so prefer that route for those.

Validation status (June 2026). jetdb 0.3 decodes DMWB's all-Text map tables cleanly (e.g. SCTICDMAP), but DMWB stores the Read v2 code in a Binary SCUI column that jetdb 0.3 returns as empty. So the Access-file Read v2 import is not viable through this path. TRUD item 9, NHS Data Migration, has now been confirmed as the preferred source for Read v2: it is the final April 2020 flat-file release. See Read v2 via TRUD item 9.

Subcommands

# List the tables in a DMWB .mdb
sct dmwb tables "DMWB NHS Data Migration Maps.mdb"

# Inspect a table's columns, types, and first rows
sct dmwb dump "DMWB NHS Data Migration Maps.mdb" SCTICDMAP --limit 5

dump reports each column's Access type and warns when a table has Binary columns that jetdb cannot decode.

Read v2 maps

Use TRUD item 9 instead of the DMWB .mdb pack:

sct trud download --edition nhs_data_migration
sct read2 import \
  --archive ~/.local/share/sct/releases/nhs_datamigration_29.0.0_20200401000001.zip \
  --db snomed.db

The primary source file is Mapping Tables/Updated/Clinically Assured/rcsctmap2_uk_20200401000001.txt. It carries a MapId, ReadCode, TermCode, target SNOMED ConceptId, target DescriptionId, IS_ASSURED, effective date, and map status. For the full one-command workflow, use sct trud download --multi-terminology. Details are documented in Read v2 via TRUD item 9.

Licensing

NHS terminology and map data is Crown Copyright under the Open Government Licence, distributed via TRUD under your own subscription. sct reads your local files and never redistributes them.