Outcome Study in Refractory Epilepsy (SOPHIE)

With a prevalence of about 0.8% in the general population, chronic active epilepsy is the most common serious neurological disorder and affects 3.7 million people in the EU alone. While the majority of patients with epilepsy can be fully controlled by available medications, about 40% fail to achieve seizure control. Refractory epilepsy is associated with poor quality of life (QoL), due to the consequences of seizures, the burden of adverse effects of antiepileptic drugs (AEDs), and associated comorbidities, especially depressed mood. In addition to human suffering, refractory epilepsy entails major costs: observational studies in Italy estimated an annual medical costs at 2,190 in adults, or 3,268 euros in children.

The study had a prospective design and mainly observational design (core study). A subgroup of patients, participated in a randomized assessment (controlled study) of the impact of utilizing a standardized tool for the assessment of adverse effects.

For the core study, the study population was represented by 1,000 consecutive consenting patients with refractory epilepsy seen as in- or outpatients at 10 major secondary/tertiary referral centres in Italy. "Refractory epilepsy" was defined as "the persistence of seizures after adequate attempts with the maximally tolerated dosage of one or more appropriate primary AEDs, excluding situations where a meaningful dose escalation was prevented by allergic or idiosyncratic adverse reactions" and at least one seizure during the previous 3 months while at steady state on the current treatment schedule. The degree of refractoriness was classified into categories.

A subcohort of patients included in the study took part in a randomized assessment of the usefulness of providing the treating physician with a standardized assessment of the adverse effect profile. The subcohort was represented by all patients enrolled in the core study who met at the first assessment visit the following additional eligibility criteria: (i) age >16 years; (ii) no progressive disorder; (iii) ability to complete the Adverse Profile AEP questionnaire, and (iv) an AEP score >=45.

For the core study, the approach was observational and the study did not interfere with clinical management. All patients were treated as considered best by the attending physician. Results of questionnaires were not made available to the treating physician until the end of the study, except for the AEP questionnaire data that were fed back to the physician only for a subgroup of patients included in the randomized assessment.

In the randomized assessment, patients meeting eligibility were randomized to two groups. In the intervention group, AEP score results were made available to the treating physician at each assessment visit, while in the other group AEP scores were only made available at the end of follow-up. Evaluations were identical to those carried out in the core study.

Except for making available the AEP scores to the treating physician, the procedures used for the collection and the handling of the information were identical in the core study and the randomized assessment. Patients were seen in the clinic at the following times: 0 (enrolment), 6, 12 and 18 months. At the first visit, detailed information were collected about demographics, medical history and current medical status. At this visit and at each of the other visits, the following information were collected:

• QOLIE-31 scores (only patients aged >16years), using the validated epilepsy-specific questionnaire, which is the most widely used for QoL tool in epilepsy in different countries;
• BDI scores (only patients aged >16years), using the validated inventory developed by Beck (1961), shown to have reliability and sensitivity in different settings, including refractory epilepsy ;
• AEP scores (only patients aged >16years), using the epilepsy-specific validated scale developed by prof. Baker ;
• A 5 digit Global Impression Scale for clinical change, compiled separately by the physician and by the patient/caregiver;
• Seizure frequency, by using seizure diaries compiled by patients and/or caregivers.
• Adverse effects, through general and neurological examination and non-structured interview;
• Drug treatment details (including, when available, serum AED levels), from the prescriber and patient's interview, and drug load scores as described by prof. Deckers;
• Items to be used for cost calculations, based on patient's records of laboratory tests, doctor's visits, specialist consultations, treatments, hospital admissions, and day-hospital days during follow up.

The study duration was 36 months.

Core study:

Inclusion criteria

• an established diagnosis of epilepsy;
• drug refractoriness, defined as persistence of seizures after adequately applied treatment(s) with one or more appropriate AEDs at maximally tolerated doses, excluding treatments whereby idiosyncratic reactions prevented titration to usually effective dosages;
• at least one seizure during the previous 6 months while at steady state on the currently used AED regimen;
• written informed consent.

Exclusion criteria

• not seizures during the previous 6 months

Inclusion criteria

for a subgroup of patients, who took part in a randomized assessment:

• age >16 years;
• no progressive disorder;
• ability to complete the Adverse Profile AEP questionnaire;
• an AEP score >=45

Exclusion criteria

• age <16 years;
• progressive disorder;
• inability to complete the Adverse Profile AEP questionnaire;
• an AEP score <45