The purpose of the Phase IV study is to investigate the effects of both Volume and Citrate on Injection Site Pain (ISP), adherence, patient satisfaction, Quality of Life, and Disease Assessment in the Canadian Adalimumab Market.

The phase IV study is an observational, pan-Canadian, multidisciplinary study aiming to enroll 600 patients across 50-70 sites across 3 different Therapeutic Areas (GI, Rheum, Derm).

The current phase 4 study seeks to assess the real-world injection experience, utilization, satisfaction, effectiveness, safety, and tolerability of treatment with AVT-02 (SIMLANDI™) in patients when switching from low-concentration adalimumab Humira® or another adalimumab biosimilar to high-concentration adalimumab SIMLANDI™ for the management of certain gastroenterological (IBD, including CD or UC); rheumatological (including RA, AS, or PsA); or dermatological conditions (including HS or PsO).

Inclusion Criteria:

1. Patient aged 18 years or older at the time of consent.

2. Patient has been diagnosed with CD, UC, RA, AS, PsA, HS, or PsO for at least 6 months.

3. Patient must be a current user of Humira® or another low-concentration adalimumab biosimilar, with treatment initiated at least 6 months prior to screening.

4. One of the following:

   1. Treating physician is considering switching from Humira® to SIMLANDI™,
   2. Treating physician is considering switching from an adalimumab biosimilar (not Humira®) to SIMLANDI™.
   3. Treating physician has switched from Humira® or Humira® biosimilar to SIMLANDI™ within the past 3 months.

5. Patient must be willing to keep using the same type of injector when switching from their previous adalimumab treatment to SIMLANDI™:

   1. Pre-filled to pre-filled switch,
   2. Autoinjector to autoinjector switch.

6. Access to commercial SIMLANDI™.

7. Patient or patient's legal/authorized representative agrees to sign informed consent and participate in the study.

Exclusion Criteria:

1. Patients previously treated with SIMLANDI™ or another high-concentration adalimumab biosimilar.
2. Patients that, in the opinion of the investigator, have any condition that may impair their ability to participate in the study.
3. Any current or history of any condition that, in the opinion of the investigator, participation in the study may increase the risk to the patient.
4. Patients for whom treatment with adalimumab may be contraindicated (e.g., patients with demyelinating disorders).
5. Patients with moderate to severe heart failure, as indicated by New York Heart Association (NYHA) class >= 3.
6. Patients with severe infections such as sepsis, tuberculosis, or opportunistic infections.
7. Patients with history of recurrent infection or with underlying conditions which may predispose them to infections.
8. Patients with known hypersensitivity to SIMLANDI™ or its excipients.
9. Patients who are unable to secure reimbursement for SIMLANDI™.
10. Patient anticipates not being available for follow-up assessments as required for adequate management.
11. Active participation in or enrollment in an interventional trial.
12. Patient or patient's legal/authorized representative cannot or will not sign informed consent.

To ensure a representative study population, any eligible patient that meets the inclusion/exclusion criteria should be invited to participate in this non-interventional study.