Qualitative validation of TnED©, an electronic instrument capturing pain dimensions in patients with trigeminal neuralgia

Background: Trigeminal neuralgia (TN) is a severe episodic facial pain that has a significant impact on mood and activities of daily living. To accurately measure pain in TN, patient diaries need to be specifically developed to capture dimensions of pain in both TN phenotypes (e.g., purely paroxysmal vs. paroxysms with concomitant continuous pain) and their impact on daily life. There is no validated pain instrument that measures specific symptoms of the pain associated with TN. Therefore, Noema Pharma decided to initiate the development and validation of such an instrument. The purpose of this study was to evaluate the content validity of the items that make up the Trigeminal Neuralgia Electronic Diary (TnED©). Methods: Participants were divided into two groups: those with purely paroxysmal pain and those with paroxysmal and concomitant continuous pain; each group was provided with a data collection instrument (diary) specific to their TN phenotype. Participants completed the instrument daily for 14 days. A qualitative, semi-structured interview was conducted to collect feedback on the instrument. Results: A total of 30 participants were enrolled in 2 English-speaking countries (USA, UK). Nearly all participants stated that the items were clear and easy to understand, relevant, measured all symptoms of the condition, and had a suitable recall period and response options. Some participants suggested additional items to be collected. Most participants regarded pain severity as the most important concept due to its debilitating impact on their lives. Few changes to the instrument were suggested, and the study sponsor decided not to implement any of the proposed changes. Conclusions: Overall, the Trigeminal Neuralgia Electronic Diary was well-received and can be used to measure symptoms of TN in clinical trials or in a clinical setting. Psychometric validation of the TnED© instrument is ongoing. Clinical Trial Registration: NCT06019338, retrospectively registered.

Trigeminal neuralgia; Validation; Pain; Qualitative; Patient reported outcomes; Content validity

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