Outcome measures in CIDP: A scoping and mapping review

Abstract

Background CIDP is a rare autoimmune disorder with varying symptom presentations. This heterogenous nature challenges standardizing disease monitoring and assessing treatment response. This study aimed to provide a comprehensive overview of clinical outcome assessments (COAs) used in CIDP. Methods A structured literature review and mapping exercise was conducted to identify COAs reported in CIDP literature published between 2010 and 2023. Supplementary searches were conducted in other relevant sources. Key publications pre-2010 were identified through handsearching or consultation with clinical experts. Clinical experts assisted with prioritization of identified COAs to those clinically relevant to CIDP. Results Overall, 2027 records were included, with 904 prioritized for COA mapping, and 524 reporting on relevant CIDP COAs. Overall, 99 different COAs were captured; the most frequent related to functional impairment, followed by humanistic burden. Three COAs were most prominent: INCAT, MRC score and I-RODS (reported in 45.6 %, 37.4 % and 29.2 % of publications respectively). Numerous CIDP biomarkers were identified; 21 publications reported on neurofilament light chain (NfL). Conclusion Substantial heterogeneity in CIDP COAs use exists. This review identified the INCAT, I-RODs, and MRC score as core measures that evaluate important, although not exhaustive, aspects of CIDP disease experience. The absence of validated CIDP biomarkers, and the heterogeneity of available COAs, may impact the assessment of CIDP treatment effectiveness. More research is needed to establish a set of comprehensive outcome measures, that are relevant to clinicians and patients with CIDP.