CHARACTERIZING THE UTILIZATION OF MAGNETOENCEPHALOGRAPHY IN THE DETERMINATION OF SURGICAL CANDIDACY IN CHILDREN AND ADOLESCENTS WITH MEDICALLY REFRACTORY EPILEPSY – A FIELD EVALUATION TO INFORM HEALTH POLICY

Purpose:   In response to a recommendation made by the Ontario Health Technology Advisory Committee (OHTAC), the purpose of this study was to examine the utilization of magnetoencephalography (MEG), which provides high-resolution recordings of cortical function and dysfunction, in the determination of surgical candidacy for children and adolescents with medically refractory epilepsy. 

Method:   A retrospective chart review of all children and adolescents referred to the Epilepsy Monitoring Unit for prolonged elective video electroencephalography (VEEG) at the Hospital for Sick Children between April 1, 2004 and March 31, 2006 was conducted.  Data was abstracted from the medical records regarding referral patterns, frequency and wait times of diagnostic tests, physician visits, multidisciplinary seizure conferences, timing of surgical candidacy decisions and subsequent surgical interventions and associated health care resource utilization.

Result:   Of the 463 referrals identified during the study period, 349 (75.4%) received prolonged VEEG.  Normalized referral patterns identified higher referral rates from northern/central areas of the province (46 to 60 referrals/1,000,000 population) where VEEG is not available.  Further evaluation for surgical candidacy in 160 (34.6%) patients identified 64 (13.8%) surgical candidates.  The median diagnostic test wait times for the majority of assessments was 100 days or more which contributed to a median time to surgical candidacy decision of 9 months.  In surgical candidates, MEG supported the surgical candidacy decision in the majority of patients (N=59; 91%) and 32 patients (54.2%) did not require invasive electroencephalography prior to surgery.  In the non-surgical candidates (N=96; 20.7%) MEG supported the decision not to proceed to surgery in 40 (41.7%) of patients.  Use of MEG prior to initial multidisciplinary seizure conference resulted in a shorter time to surgical candidacy decision (median = 193 days, N=41) as compared to later use of MEG following first conference (median = 482 days, N=18).

Conclusion: The characterization of the use of MEG to provide evidence to inform policy decision making resulted in the identification of other healthcare resource and waiting time issues.  The evaluation of diagnostic medical technologies along with their utilization within the healthcare system can result in the identification of additional system related problems that can be addressed.  The results of the study identified system inefficiencies, a need for coordinated care/services and standardization, and as a result, a provincial-wide epilepsy care program is under development.