A Study to Investigate Effectiveness of Tirzepatide Following Initiation of Ixekizumab in Participants With Active Psoriatic Arthritis and Overweight or Obesity in Clinical Practice (TOGETHER AMPLIFY-PsA)

Inclusion Criteria: * Have a diagnosis of active psoriatic arthritis (PsA) as defined by a rheumatologist or other healthcare professional (HCP) experienced in treating PsA. * Body Mass Index (BMI) of 30 kilograms per meter squared (kg/m²) or greater (obesity) or 27 kg/m2 to \<30 kg/m² (overweight) in the presence of at least 1 weight-related comorbid condition (hypertension, dyslipidemia, type 2 diabetes, obstructive sleep apnea, or cardiovascular disease). * Who have been treated with ixekizumab for approximately 3 months (±1 month) prior to decision to add tirzepatide. * Must be able to initiate tirzepatide (Day 0) within 30 days of treatment decision (baseline or screening). Exclusion Criteria: * Have currently received ixekizumab for more than 4 months or less than 2 months. * Had any exposure to tirzepatide or other glucagon-like peptide-1 (GLP-1) receptor agonist (for example, dulaglutide, liraglutide, or semaglutide). * Are currently enrolled in any other clinical study. * Have a known hypersensitivity to any component of tirzepatide. * Have a personal or family history of medullary thyroid cancer. * Have multiple endocrine neoplasia type 2. * Have type 1 diabetes mellitus. * Have a history of chronic or acute pancreatitis at any time before screening. * Have a history of proliferative diabetic retinopathy, diabetic maculopathy, or nonproliferative diabetic retinopathy that requires acute treatment. * Have a history of ketoacidosis or hyperosmolar state/coma. * Have a history of severe hypoglycemia unawareness within the 6 months before screening. * Have a history of severe gastrointestinal complications, including gastroparesis, gastroesophageal reflux disease, dyspepsia, chronic nausea/vomiting.