# The journey to diagnosis for patients with CIDP: results from a real-world international survey

## TL;DR

This study explores how patients with CIDP are diagnosed, finding that many face delays and misdiagnoses, often with symptoms mistaken for Guillain-Barré syndrome.

## Contribution

The study provides new insights into diagnostic delays and misdiagnoses in CIDP patients through a multinational real-world survey.

## Key findings

- Median time to CIDP diagnosis is 7 months, with 37% of patients experiencing at least one misdiagnosis.
- Mild symptoms at onset, variant CIDP, and prior misdiagnosis are linked to longer diagnostic delays.
- Guillain-Barré syndrome was the most frequent misdiagnosis for CIDP patients.

## Abstract

Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) is a rare autoimmune disorder affecting the peripheral nerves, typically characterized by muscle weakness and sensory deficits. This study seeks to describe CIDP patients’ journey to diagnosis alongside factors influencing misdiagnosis and time to diagnosis.

We analyzed demographics and diagnostic data reported by neurologists and their patients in Adelphi’s CIDP Disease Specific Programme™. This digital, multinational real-world survey was held in the UK, France, Germany, Italy and Spain between September 2022 and April 2023 (n = 542).

Mean (SD) age was 54.0 (12.4) years; 62% of patients were male. Half of the patients reported at least one comorbidity, with anxiety, depression and diabetes being the most common. The mean (SD) number of diagnostic procedures undergone per patient was 19.6 (9.4). An electromyogram and nerve conduction study (98%), complete blood count (82%) and administration of anti-ganglioside antibodies (78%) were carried out most frequently. Most patients had been diagnosed with typical CIDP (68%) and 37% had been misdiagnosed at least once. The most common misdiagnosis was Guillain-Barré syndrome, in 37% of cases. No significant associations were found between misdiagnosis and the variables sex, disease severity at symptom onset, age category, BMI or CIDP subtype. The median (Q1 - Q3) time between symptom onset and diagnosis was 7.0 (3.2–13.0) months. A multiple linear analysis on the log-transform of the time to diagnosis indicated that patients with a long time to diagnosis more often presented with mild symptoms at onset, had variant CIDP and had been misdiagnosed.

Median time to diagnosis for CIDP patients was 7 months; over a third had at some point been misdiagnosed. Mild symptoms, having variant CIDP and having been misdiagnosed were associated with longer time to diagnosis. Further research into the causes of diagnostic delay and the impact of late diagnosis and treatment is needed.