Methotrexate is one of the immunosuppressants used in chronic inflammatory bowel disease (IBD). It is indicated as monotherapy for induction and maintenance treatment of Crohn's disease (CD), or in combination with anti-tumor necrosis factor (TNF) agents for prevention of immunization.

The main objective is to assess the persistence rate of methotrexate treatment in patients followed for chronic inflammatory bowel disease (IBD).

Methotrexate is one of the immunosuppressants used in chronic inflammatory bowel disease (IBD). It is indicated as monotherapy for induction and maintenance treatment of Crohn's disease (CD), or in combination with anti-tumor necrosis factor (TNF) agents for prevention of immunization Thiopurines are the most commonly used immunosuppressants in IBD, which contrasts with rheumatology data where methotrexate is the first-line immunosuppressant. Thiopurines and methotrexate have equivalent efficacy in CD 4.

Methotrexate is available in injectable (intramuscular (IM) or subcutaneous (SC)) or tablet form. In IBD, only parenteral administration has been shown to be effective. There is no consensus on the optimal maintenance dosage.

Tolerance problems remain an obstacle to its use, even if the side effects are not severe.

In this context, the objectives of this study are to describe the use of methotrexate in current practice in patients followed for IBD, its persistence, compliance, tolerance, as well as the factors associated with the persistence of treatment.

Inclusion Criteria:

1. Person who has received full information on the organization of the research and has not objected to the use of this data
2. Age ≥18 years
3. Certain diagnosis of IBD (European Crohn's Colitis Organization criteria)
4. Introduction of methotrexate mono- or combination therapy between January 1, 2015 and December 31, 2022
5. Minimum 6-month follow-up after initiation of methotrexate therapy
6. Person affiliated with a social security plan or beneficiary of such a plan

Exclusion Criteria:

1. Age <18 years

2. Person referred to in articles L. 1121-5, L. 1121-7 and L1121-8 of the public health code

   • Pregnant woman, parturient or nursing mother
   • Minor (not emancipated)
   • Adult person subject to a legal protection measure (guardianship, curatorship, safeguard of justice)
   • A person of full age who is unable to give consent

3. Persons deprived of liberty by a judicial or administrative decision, persons under psychiatric care by virtue of articles L. 3212-1 and L. 3213-1

All patients followed for IBD treated with methotrexate between 01/01/2015 and 12/31/2022.