Table 2

Specification of outcome chronic inflammatory diseases (CIDs) with associated diagnostic code and treatment codes

CIDDiagnostic code (NPR)Medical treatment (DNPR and NPR)Department with relevant area of specialisation
ICD-8*ICD-10ATC code (DNPR)†Treatment code (NPR)†
Crohn’s disease (CD)563.00, 563.02, 
563.08,
563.09,
563.91		K50.0–50.9L04AB02
L04AB04
L04AB06
L04AB05
L04AA33
L04A×01
L04A×03
L01BB02
A07E		BOHJ18A1
BOHJ18A3
BOHJ18A4
BOHJ18A5
BOHJ26
BOHJ19H4		Gastroenterology,
internal medicine
Ulcerative colitis (UC)563.99, 563.19
569.04		K51.0–51.9Gastroenterology,
internal medicine
Chronic polyarthritis, including RA712.19, 712.29, 712.39, 712.59M05.9, M06.0L04A×01
L04A×03
L04AA13
P01BA02		BWHA115
BLHM2
BWHB83
BOHJ18		Rheumatology, internal medicine
Psoriatic arthritis696.09M09.0, M07.3, M46.8+M07.2Rheumatology,
internal medicine
Psoriasis696.10, 696.19L40.0–40.9D05A×02
D05BB02
D05B
L04AA32
L04AB01-02
L04AB04
L04AC05
L04AC10
L04AC13
L04AD01
L04A×03		BWHA115
BOHJ20
BNHC
BOHJ18A1-3
BOHJ18B3
BOHJ18B5		Dermatology,
internal medicine
Multiple sclerosis (MS)734.0–9‡G35.9‡Not usedNot usedDanish Multiple Sclerosis Registry (DMSR)

  • *International Classification of Disease (ICD)-8 and ICD-10 codes will be used to define participants with a CID diagnosis.

  • †These Anatomical Therapeutic Chemical classification (ATC) and treatment codes for CD and UC are used by the Danish National Registry for Biological Therapy in Inflammatory Bowel Disease.98

  • ‡ICD-8 and ICD-10 codes for MS will be extracted from the DMSR.

  • DNPR, Danish National Prescription Registry; NPR, National Patient Registry; RA, rheumatoid arthritis.