Longitudinal Assessment of Quality of Life and Functionality by CAP-PRI in Patients With Active Chronic Inflammatory Demyelinating Polyradiculoneuropathy.

BACKGROUND AND AIMS: In most studies to date, generic health-related quality of life (QoL) questionnaires have been used in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Unfortunately, these tools are often considered insufficient for capturing the unique characteristics of this specific, rare disease. The Chronic Acquired Polyneuropathy Patient-Reported Index (CAP-PRI) is a measure which specifically targets patients with chronic immune-mediated polyneuropathies. This is the first study which longitudinally assessed QoL and functionality by CAP-PRI in patients with active CIDP.

METHODS

CAP-PRI testing was conducted at three time points (baseline, year one and year four) in 57 CIDP patients with active disease at baseline. In addition, the Medical Research Council Sum Score (MRC-SS), Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Inflammatory Rasch-built Overall Disability Scale (I-RODS), and the generic QOL instrument, the Short Form 36 (SF-36) were used in all tested patients at all three time points.

RESULTS

At the baseline and two other time points, CAP-PRI showed strong correlations with impairment (MRC-SS), functionality (INCAT, I-RODS), and the SF-36. At year one and year four, CAP-PRI was able to make a differentiation between patients whose impairment/disability improved compared to patients who deteriorated, and it performed better than SF-36. One- and four-year changes in CAP-PRI correlated with a change in MRC-SS, INCAT, and I-RODS.

INTERPRETATION: CAP-PRI is a highly reliable and sensitive measure for assessing QoL in patients with active CIDP. Its consistent performance over time supports its utility in monitoring CIDP patients with active disease in clinical and research settings.