Category recoding crosswalk =========================== StatMedAnalysis | Original downloadable worksheet | 6 November 2026 Document how source categories map to analysis categories and what information is lost. How to use this worksheet List every source code, including missing and unknown values. Assign one explicit target code or unresolved disposition to each. Compare counts before and after recoding and examine rare categories. Preserve the original variable so the transformation can be reversed or audited. Save a working copy and keep the original blank version. Use public, hypothetical or aggregate information only; do not enter patient identifiers, credentials or confidential records. Keep source evidence in your approved project workspace. Mark unresolved text fields UNKNOWN or NOT REPORTED with a reason; never substitute zero for an unknown count. Project/version __________________ Prepared by role/date __________________ Working fields 1. Source variable and version Response/evidence: _________________________________________________________ ___________________________________________________________________________ 2. Source code and label Response/evidence: _________________________________________________________ ___________________________________________________________________________ 3. Target code and label Response/evidence: _________________________________________________________ ___________________________________________________________________________ 4. Scientific reason for grouping Response/evidence: _________________________________________________________ ___________________________________________________________________________ 5. Unknown and missing handling Response/evidence: _________________________________________________________ ___________________________________________________________________________ 6. Before/after aggregate counts Response/evidence: _________________________________________________________ ___________________________________________________________________________ 7. Information loss and sensitivity Response/evidence: _________________________________________________________ ___________________________________________________________________________ 8. Script and reviewer Response/evidence: _________________________________________________________ ___________________________________________________________________________ Hypothetical worked case A fictional file uses 9 for unknown and 0 for no. Combining 9 with 0 would change unknown responses into negatives; the crosswalk keeps these meanings distinct. Decision rule and limitations Require exhaustive, nonoverlapping mappings and reconciled counts. Do not collapse categories solely to obtain a preferred p-value or conceal sparse groups. Decision _______________________ Remaining uncertainty ____________________ Next action ____________________ Owner / review date ______________________ Independent check and discrepancy resolution _______________________________ Official method or reporting reference checked 6 November 2026 https://ukdataservice.ac.uk/learning-hub/research-data-management/ This is an original planning aid, not an official checklist, validated instrument, clinical recommendation or certificate of expert approval. Apply the referenced guidance to the specific design and record any additional requirements.