A Safety Study of GAMMAGARD LIQUID (GGL) in Participants With Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP)

Inclusion Criteria: * Have a minimum of 6 months of continuous enrollment in the study database with medical and pharmacy coverage before the index date. Gaps in continuous enrollment less than or equal to (\<=) 31 days are permitted. * Fulfill the Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) diagnosis algorithm on or before the index date using all available baseline data for each participant. * Additionally, to be eligible for the Ig-naive (new-to-class) cohort, participants will be required to meet the following inclusion criterion: * Be free of any previous recorded use of any Ig product at any point before IVIG initiation. * To be eligible for the Ig-experienced (new-to-drug) cohort, participants will be required to meet the following inclusion criterion: * Have any previous recorded use of an Ig product at any point before the index date. Exclusion Criteria: * Having claims for greater than or equal to (\>=) 2 different IVIG products on the index date. * Recorded diagnosis of any of the following conditions where Ig products are used for treatment on or before the index date 1. Primary immunodeficiency disease (PID). 2. Evidence of secondary immunodeficiency (SID), including hematological malignancy (e.g., diagnosis of multiple myeloma or chronic lymphocytic leukemia) or treatment with rituximab. 3. Idiopathic thrombocytopenic purpura (ITP). 4. Dermatomyositis or polymyositis. 5. Systemic sclerosis/scleroderma. 6. Myasthenia gravis.