Understanding the Patient Perspective of Seizure Severity in Epilepsy: Development of a Conceptual Model

For patients with uncontrolled epilepsy, the severity and postictal sequelae of seizures might be more impactful than their frequency. Seizure severity is often assessed using patient-reported outcome (PRO) instruments; however, evidence of content validity for existing instruments is lacking. Our aim was to understand the real-life experiences of patients with uncontrolled epilepsy.

A preliminary conceptual model was developed. The model was refined through (1) a targeted literature review of qualitative research on seizure severity; (2) interviews with four clinical epilepsy experts to evaluate identified concepts; and (3) qualitative interviews with patients with uncontrolled epilepsy, gathering descriptions of symptoms and impacts of epilepsy, focusing on how patients experience and describe "seizure severity." Findings were summarized in a final conceptual model of seizure severity in epilepsy.

Twenty-five patients (12 who experienced primary generalized tonic-clonic seizures and 13 who experienced partial-onset seizures) expressed 42 different symptoms and 26 different impacts related to seizures. The final conceptual model contained a wide range of concepts related to seizure frequency, symptoms, and duration.

Our model identified several new concepts that characterize the patient experience of seizure severity. A seizure severity PRO instrument should cover a wide range of seizure symptoms alongside frequency and duration of seizures. This qualitative work reinforces the notion that measuring seizure frequency is insufficient and that seizure severity is important in defining the patient's experience of epilepsy. This model could be used to assess the content validity of existing PRO instruments, or could support the development of a new one.