Find your registers
Which register contains what - and how they are linked
You can now inspect a dataset. The next step is to know where your variables come from: which register contains demographics, which contains diagnoses, which contains prescriptions.
This page is your decision table. Once you know which register to use, you find the exact column names, types and code examples in Overview of registers, or search for a single variable across all of them in Find a variable.
What a register holds is not what your project was given. The table below says which register covers what at DST. Which of its columns and years you actually received was decided when the data was ordered, so confirm with colnames() before you plan around anything here.
What am I looking for? - decision table
Know your question. Find the register. Look in the column.
| I want to find… | Register | Key column(s) |
|---|---|---|
| Date of birth and sex | BEF | foed_dag, koen |
| Whether a person has died - and when | DOD | doddato |
| Whether a person has emigrated | VNDS | haend_dato, indud_kode |
| A somatic hospital contact (before 2019) | lpr_adm | d_inddto, recnum, c_pattype |
| A somatic diagnosis (before 2019) | lpr_diag | c_diag, c_diagtype, recnum |
| A psychiatric diagnosis (e.g. dementia, before 2019) | t_psyk_adm + t_psyk_diag | d_inddto, c_diag, c_diagtype |
| A hospital contact or diagnosis (2019+) | lpr_a_kontakt + lpr_a_diagnose | kont_starttidspunkt, diag_kode, diag_kode_type |
| A dispensed prescription | LMDB | atc, eksd |
| Education level | UDDA | hfaudd, year |
| Household income | FAIK | famaekvivadisp_13, familie_id |
| Employment status | AKM | socio13, year |
| An incident cancer diagnosis | The Cancer Register | pnr - see variable list |
| A primary-sector contact (GP/specialist) | sysi (older) / sssy (newer) | pnr - see variable list |
| A laboratory result (e.g. HbA1c) | laboratorieproevesvar_ | pnr, NPU code, samplevalue - see variable list |
| A surgical procedure / SKS code | lpr_sksopr (LPR2) / project-specific (LPR3) | c_opr, recnum (LPR2) - LPR3: see Overview of registers §5 |
| An examination / treatment (ZZ code) | lpr_sksube | recnum - see variable list |
SKS (Sundhedsvæsenets Klassifikations System - the Danish Health Classification System) is the Danish system for coding operations and procedures in hospital - e.g. KJDF10 for Roux-en-Y gastric bypass. Equivalent to the NOMESCO codes used in the other Nordic countries.
The socioeconomic registers come as a set
The three socioeconomic registers - UDDA (education), FAIK (income) and AKM (employment) - are extracted together in Socioeconomic variables. One trap worth knowing before you start: UDDA’s hfaudd is a code for the specific education, not its level, so getting a level out of it needs a lookup - see Overview of registers.
Join keys
Wrong join keys produce silent errors: the code runs, but you lose rows - or duplicate them.
| Register | Join key | Links to |
|---|---|---|
| BEF, DOD, VNDS, LMDB, UDDA, AKM, The Cancer Register, sysi/sssy, laboratorieproevesvar_ | pnr |
All other pnr registers |
| FAIK | familie_id |
Fetched from the BEF column familie_id |
lpr_diag |
recnum |
lpr_adm |
lpr_sksopr |
recnum |
lpr_adm |
lpr_sksube |
recnum |
lpr_adm |
lpr_a_diagnose |
dw_ek_kontakt |
lpr_a_kontakt |
Confirmed column names and join examples for each register are in Overview of registers. The mechanics of joins are covered in Phase 12 - Assemble and prepare the dataset.
Next steps
- Need the exact column names, types and code examples? → Overview of registers
- Need to extract hospital diagnoses? → Understand LPR
- Want to know which variables and registers exist at all, or need an application template? → Steno Aarhus keeps a register project database. It covers what exists; this guide covers how to code the extraction.
Working on DARTER / project 708421? The project uses among others DBSO (the Danish Obesity Treatment Database) and OSDC (Open Source Diabetes Classifier). See the full register overview with confirmed column names and paths: DARTER - Register paths and datastores →