A Study of HyQvia in Adults With Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) in Routine Clinical Care

Treatment Preference for CIDP Therapy as Measured by Novel Treatment Preference Questionnaires

The novel treatment preference questionnaires measure participant's treatment preferences for switching to HyQvia from other subcutaneous immunoglobulin/intravenous immunoglobulin (SCIG/IVIG) treatments for CIDP. It includes overall preference for switching from prior therapy to HyQvia, reason for switching from prior therapy type (like other SCIG, IVIG, corticosteroids, or plasma exchange) to HyQvia for the maintenance treatment of CIDP, current/future preference for HyQvia, reason for HyQvia or study discontinuation, and details on previous treatment setting/components for other subcutaneous immunoglobulin (SCIG) or intravenous immunoglobulin (IVIG) user only. Users will be presented a maximum of 8 questions at baseline, 2 questions at Month 12, 2 questions if HyQvia is discontinued, and 4 questions if the study is discontinued. The questionnaires will be self-administered.

Treatment Satisfaction With HyQvia as Measured by the Treatment Satisfaction Questionnaire for Medication (TSQM) Short Form-9

The TSQM is a 9-item questionnaire which assesses domains that include effectiveness, convenience, and global satisfaction. The instrument is self-administered. Response options fall on a 5- or 7-point Likert/Likert-type scale with scores ranging from 0 to 100 and higher scores indicating a higher level of treatment satisfaction.

Health-Related Quality of Life (HRQoL) as Measured by the Chronic Acquired Polyneuropathy Patient Reported Index (CAP-PRI)

The CAP-PRI is a disease-specific HRQoL measure designed to assess diabetic polyneuropathy. This 15-item questionnaire assesses various life domains including physical and social functioning, pain, and emotional well-being. Items will be scored 0 (not at all), 1 (a little bit), or 2 (a lot). Individual scores within the CAP-PRI may be summed to a total score ranging from 0 to 30 that indicates the level of disease impairment, with higher scores representing higher degrees of impairment.

CIDP Signs, Symptoms, and Impacts, as Measured by the Inflammatory Rasch-built Overall Disability Scale (I-RODS)

The I-RODS is a linearly weighted scale developed to capture activity and social participation limitations in participants with Guillain-Barré syndrome and CIDP. This 24-item questionnaire assesses domains that include activity and social participation. Response options include a categorical rating scale where 0 is "Not possible to perform," 1 is "Possible with some difficulty," and 2 is "Possible, without any difficulty," with a lower score indicating more severe activity and social participation limitations.

Number of Participants With Serious Adverse Events (SAEs) and All Non-serious Adverse Events (AEs) Causally or Temporally Relationship to HyQvia Treatment

SAE is any untoward medical occurrence that at any dose: results in death, life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent, significant disability/incapacity, a congenital abnormality/birth defect, an important medical event in opinion of healthcare provider, may jeopardize the participant or may require intervention to prevent one of other outcomes listed in definition above. Non-serious AEs are the AEs that do not meet SAEs definition. Related AE: AE that follows a reasonable temporal sequence from administration of medication, vaccine, or device (including the course after withdrawal of the medication), and for which a causal relationship is at least a reasonable possibility, i.e., relationship cannot be ruled out, although factors other than medication, vaccine or device, such as underlying diseases, complications, concomitant drugs and concurrent treatments, may also have contributed.

Number of Participants With Adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) Increase of >=1 point Relative to the Baseline

The INCAT disability score is a measure of activity limitation. The INCAT disability score ranges from 0 to 10 and is the sum of arm and leg disability each rated between 0 and 5 (where arm = 0 indicates 'no upper limb problems' and arm = 5 indicates 'inability to use either arm for any purposeful movement', and leg = 0 indicates 'walking not affected', and leg = 5 indicates 'restricted to wheelchair, unable to stand and walk a few steps with help'). Thus, a higher INCAT disability score indicates greater disability. The adjusted INCAT disability score remains identical to INCAT disability score, except that the changes in upper limb function from 0 (normal) to 1 (minor symptoms) are excluded.

Change From Baseline in Adjusted INCAT Disability Score

The INCAT disability score is a measure of activity limitation. The INCAT disability score ranges from 0 to 10 and is the sum of arm and leg disability each rated between 0 and 5 (where arm = 0 indicates 'no upper limb problems' and arm = 5 indicates 'inability to use either arm for any purposeful movement', and leg = 0 indicates 'walking not affected', and leg = 5 indicates 'restricted to wheelchair, unable to stand and walk a few steps with help'). Thus, a higher INCAT disability score indicates greater disability. The adjusted INCAT disability score remains identical to INCAT disability score, except that the changes in upper limb function from 0 (normal) to 1 (minor symptoms) are excluded.

Change From Baseline in Hand Grip Strength

Grip strength assessments conducted by prescribing physicians using the Martin Vigorimeter or the Jamar Dynamometer (as available at the site and performed per routine clinical practice).