Inclusion Criteria:  Has a diagnosis of CD documented in the medical records. Has received at least one dose of vedolizumab or ustekinumab at one of the participating study sites during the eligibility period. Was biologic-naïve (no prior biologic use for any pathology, including CD) at the time of index event. Has completed induction phase and has a minimum of a six-month duration between the date of the index event and the date of chart abstraction initiation and was still under active care at the site six months post-index date.  Exclusion Criteria:  Has received vedolizumab or ustekinumab as part of a clinical trial in their lifetime (includes index event). Has initiated index treatment as combination therapy with two biologic agents. Has received previous treatment with biologic agents for CD or conditions other than CD ever in their lifetime. Has medical chart empty or missing. Part or all of the participant's index treatment was received at a different site, and the participant's medical chart pertaining to this care is not accessible. Has received a subcutaneous formulation of ustekinumab for induction (that is, a subcutaneous induction dose of ustekinumab prior to ustekinumab's approval for CD in the study countries).