Patient perceptions of outcome measures in chronic inflammatory demyelinating polyneuropathy: A study of the Inflammatory Rasch‐built Overall Disability Scale

Background Patients' perceptions of outcome measures used in chronic inflammatory demyelinating polyneuropathy (CIDP) are unknown. Methods We performed a cross‐sectional evaluation of patient perceptions of the Inflammatory Rasch‐built Overall Disability Scale (I‐RODS) from 41 subjects with CIDP through a structured questionnaire. We assessed perceived hesitation to provide a response, item importance and relevance, understanding of specific items and factors affecting responses. Results Hesitation to provide a categorical answer was reported by 20% of subjects or more, for 5/24 (20.8%) items. Uncertainty was most frequent for “travel by public transport” (22.4%) and “catch an object (e.g., ball)” (24%). Six of 24 (25%) items were perceived as unimportant to their disease by at least a third of participants. Items most commonly perceived as unimportant were “travel by public transport” in 53.7%, “catch an object (e.g., ball)” in 61% and “dance” in 65.9%. Several items were frequently perceived as irrelevant. These included “move a chair” (39%), “do the dishes” (46.3%), “catch an object (e.g., ball)” (61%), “travel by public transport” (68.3%) and “stand for hours” (82.9%). The understanding of multiple items such as “read a book”, “sit on a toilet” and “take a shower” was found to be highly variable. Fatigue was perceived more commonly than mood (53.7% vs. 17.1%, p  = 0.001), and more commonly in younger subjects ( p  = 0.037), as influencing responses to the I‐RODS. Conclusions Patient‐perceived uncertainty, unimportance, irrelevance and poor understanding of items, as well as fatigue and mood, impact on the value of the I‐RODS. Greater emphasis on individualized disability assessments requires consideration in future.