Determinants of long‐term disability in chronic inflammatory demyelinating polyradiculoneuropathy: A multicenter Korea/UK study of 144 patients

Background Despite standard‐of‐care treatment, therapeutic outcomes in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are often incomplete. We aimed to evaluate the impact of clinical and therapeutic factors on long‐term disability in CIDP, from cohorts from Korea and the UK. Methods We conducted a retrospective multicenter cohort study of 144 patients with CIDP. Baseline characteristics and treatment data were collected, and disability was assessed using the Overall Neuropathy Limitation Scale (ONLS) for the UK cohort, Inflammatory Neuropathy Cause and Treatment (INCAT) scores for the Korean cohort, and Inflammatory Rasch‐built Overall Disability Scale (I‐RODS) for the combined cohort. Univariate and multivariate linear regression analyses were performed to identify independent prognostic factors. Subgroup analyses were conducted according to important clinical features to gain further insights into which patients are most likely to benefit from early treatment. Results Treatment initiation within 1 year of onset was significantly associated with lesser post‐treatment disability and greater amplitude of treatment response, in each cohort separately, and in the combined cohort. This association remained significant after adjusting for covariates in multivariate regression. Subgroup analyses demonstrated early treatment benefits in older patients (≥60 years), those with typical CIDP, and those with a chronic mode of onset. The type of first‐line therapy and baseline disability levels did not influence outcomes. Other identified independent prognostic factors included comorbidity and pre‐treatment disability level. Discussion Early treatment initiation is a key modifiable determinant of favorable long‐term disability in CIDP. These findings underscore the importance of timely diagnosis and prompt treatment to prevent irreversible axonal damage.