A Study on Infections in Adults With Ulcerative Colitis/Crohn's Disease

Inclusion Criteria: UC Study Cohort: Participants will be included if they had: -Greater than or equal to (\>=) 1 medical (for Medicare fee-for-service \[FFS\], Part A/B) or pharmacy claim (for Medicare FFS, Medicare Part D) for an approved AMT for UC during the participant identification period. Note: Claim should be on or after the food and drug administration (FDA) treatment-specific approval dates for each drug. The date of the first claim during the participant identification period will be designated the Index Date, and the corresponding AMT, the index AMT. * \>=2 medical (for Medicare FFS, Part A/B) claims, at least 30 days apart, with an ICD-10-CM code for UC during the baseline period or on the Index Date. * Continuous enrollment in either Medicare FFS or Medicare Advantage medical and pharmacy benefits during the Baseline Period. CD Study Cohort: Participants will be included if they had: \- \>=1 medical (for Medicare FFS, Part A/B) or pharmacy claim (for Medicare FFS, Part D) for an approved AMT for CD during the Participant Identification Period. Note: Claim should be on or after the FDA treatment-specific approval dates for each drug. The date of the first claim during the Patient Identification Period will be designated the Index Date, and the corresponding AMT, the index AMT. * \>=2 medical (for Medicare FFS, Part A/B) claims, at least 30 days apart, with an ICD-10-CM code for CD during the Baseline Period or on the Index Date. * Continuous enrollment in either Medicare FFS or Medicare Advantage medical and pharmacy benefits during the Baseline Period. If a participant has both a UC and CD diagnosis during the baseline period or on the index date, the diagnosis most proximate to or on the index date will be used to categorize the participant as having UC or CD. Exclusion Criteria: Participants with any of the following will be excluded from the analysis: * Any evidence of AMT utilization during the Baseline Period. * Participants with at least 2 ICD-10-CM codes for rheumatoid arthritis, ankylosing spondylitis, plaque psoriasis, hidradenitis suppurativa, juvenile idiopathic arthritis, non-infectious uveitis, or psoriatic arthritis during the Baseline Period. * Participants with 2 or more ICD-10-CM codes for non-dermatologic malignancy during the Baseline Period.