Optimizing the Use of Outcome Measures in Chronic Inflammatory Demyelinating Polyneuropathy

Abstract

The challenges encountered during the assessment of patients with chronic inflammatory demyelinating polyneuropathy (CIDP) are many. Ideally, CIDP outcome measures capture impairments in disability, strength, and sensory dysfunction, and quality of life (QoL). A number of outcome measures have been validated for this purpose. Disability outcomes include the adjusted inflammatory neuropathy cause and treatment (INCAT) disability score, INCAT overall disability sum score (ODSS), and overall neuropathy limitations scale (ONLS). A more sensitive disability score, the inflammatory Rasch-built overall disability scale (I-RODS), has also been validated for use in clinical trials and may better capture clinically meaningful changes in those with CIDP. Strength and sensory impairment can be assessed in a number of ways, including the INCAT sensory subscore (ISS), Medical Research Council sum score, and Martin vigorimeter or Jamar dynamometer grip strength. However, the feasibility of applying and interpreting these measures during routine daily practice has been questioned. Furthermore, these outcome measures may not reflect other factors that can impair QoL in those affected by CIDP, such as pain and fatigue. A valid, reliable, and responsive composite measure that addresses all aspects of impairment faced by patients with CIDP remains an unmet need in clinical practice.

Validation of the Serbian version of inflammatory Rasch‐built overall disability scale in patients with chronic inflammatory demyelinating polyradiculoneuropathy

“…Moreover, ordinal‐oriented measures such as INCAT have significant limitations, such as the fact that individual items of the sum scores are not equal‐weighted and cannot be presented linearly. Thus, slight but important clinically changes could be easily overlooked by ordinal‐based measures . On the other hand, I‐RODS is more suitable for detecting differences, while a change of one point on INCAT disability scale can be implied on narrow range of clinical presentations .…”

“…Thus, slight but important clinically changes could be easily overlooked by ordinal‐based measures . On the other hand, I‐RODS is more suitable for detecting differences, while a change of one point on INCAT disability scale can be implied on narrow range of clinical presentations . I‐RODS represents the patient's selection of many everyday activities reflecting general functionality.…”

“…Although widely used, this activity measure is ordinal‐based and has limitations which could hamper the comparison between patients and between different trials . In order to overcome these limitations and ensure exactness, the Inflammatory Rasch‐built Overall Disability (I‐RODS) scale was created . The Rasch model is a process of creating interval‐based measure which could obtain more precise information of disease impact .…”

“…4 In order to overcome these limitations and ensure exactness, the Inflammatory Rasch-built Overall Disability (I-RODS) scale was created. [5][6][7] The Rasch model is a process of creating interval-based measure which could obtain more precise information of disease impact. 6 7 Also, I-RODS and the INCAT disability scale will be used as activity and participation measures in the international CIDP registry.…”

The Misdiagnosis of CIDP: A Review

“…The findings were highly complementary. Only 11% [6] and 19% [7] of patients diagnosed and treated as having CIDP in these community-based settings met minimum CIDP diagnostic standards [6,7]. Although in many cases a diagnostic opinion could not be reached due to poor or incomplete documentation, the findings were nonetheless alarming.…”