Management of Newly Diagnosed Patients with Epilepsy: A Systematic Review of the Literature

Prepared for:
Agency for Healthcare Research and Quality
U.S. Department of Health and Human Services
2101 East Jefferson Street
Rockville, MD 20852

Prepared by:
MetaWorks, Inc. Medford, MA
Susan D. Ross, MD, FRCPC
Principal Investigator

Rhonda Estok, RN, BSN
Sameer Chopra, MA
Jacqueline French, MD
Investigators

This report may be used, in whole or in part, as the basis for development of clinical practice guidelines and other quality enhancement tools, or as a basis for reimbursement and coverage policies. Endorsement by the Agency for Healthcare Research and Quality (AHRQ) or the U.S. Department of Health and Human Services (DHHS) of such derivative products may not be stated or implied.

AHRQ is the lead Federal agency charged with supporting research designed to improve the quality of health care, reduce its cost, address patient safety and medical errors, and broaden access to essential services. AHRQ sponsors and conducts research that provides evidence-based information on health care outcomes; quality; and cost, use, and access. The information helps heath care decisionmakers -- patients and clinicians, health system leaders, and policymakers -- make more informed decisions and improve the quality of health care services.

The Agency for Healthcare Research and Quality (AHRQ), formerly the Agency for Health Care Policy and Research, through its Evidence-based Practice Centers (EPCs), sponsors the development of evidence reports and technology assessments to assist public- and private-sector organizations in their efforts to improve the quality of health care in the United States. The reports and assessments provide organizations with comprehensive, science-based information on common, costly medical conditions and new health care technologies. The EPCs systematically review the relevant scientific literature on topics assigned to them by AHRQ and conduct additional analyses when appropriate prior to developing their reports and assessments.

To bring the broadest range of experts into the development of evidence reports and health technology assessments, AHRQ encourages the EPCs to form partnerships and enter into collaborations with other medical and research organizations. The EPCs work with these partner organizations to ensure that the evidence reports and technology assessments they produce will become building blocks for health care quality improvement projects throughout the Nation. The reports undergo peer review prior to their release.

AHRQ expects that the EPC evidence reports and technology assessments will inform individual health plans, providers, and purchasers as well as the health care system as a whole by providing important information to help improve health care quality.

We welcome written comments on this evidence report. They may be sent to: Director, Center for Practice and Technology Assessment, Agency for Healthcare Research and Quality, 6010 Executive Blvd., Suite 300, Rockville, MD 20852.

The authors wish to acknowledge the following individuals for their diverse contributions throughout the course of this task order: Rebecca Cintron, Janet Connelly, Matthew Gordon, Cindy Levine, Joanne Levy, Elaine Milardo, Luba Nalysnyk, Michael Rozinsky, Shuhuan Zhang, and Isabella Sledge.

The objective of this evidence report was to systematically review the best available evidence in the published literature regarding health care services pertinent to the diagnosis, treatment, and monitoring of patients with a first diagnosis of epilepsy.

Literature published in English from 1980 through November 1999 was searched using MEDLINE and Current Contents, supplemented by a manual review of the bibliographies of all accepted papers, the Cochrane Library of Systematic Reviews, and various Internet sources.

Interventional or observational studies of at least 10 patients, adults, or children, with a first seizure, or at first presentation, or at the time of a new diagnosis of epilepsy, were eligible. Studies had to report results of any of the following interventions: (a) diagnostic: history and physical examination; neuropsychologic examination; imaging with computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET) scan; electroencephalogram (EEG) -- standard, video, invasive, ambulatory; lumbar puncture; or blood tests; (b) monitoring: EEG, blood tests, drug levels, or clinical/pharmacologic expertise; (c) treatment: clinical/pharmacologic expertise, antiepileptic drug monotherapy or polytherapy, counseling and psychosocial support, surgery, physical or occupational therapy, speech therapy, or education.

Data on study, patient, and intervention characteristics and results were extracted from accepted studies. Studies were scored for quality and level of evidence. Study and patient-level characteristics were summarized, and the results were synthesized qualitatively. A panel of diverse technical experts and peer reviewers provided review and commentary on the results.

Of 13,128 citations, 120 studies covering 21,213 patients met all eligibility criteria. Diagnostic interventions to rule in a diagnosis of epilepsy, as well as predict remission outcomes, are a complete history and physical examination, including neuropsychologic assessment, and a standard EEG. Other diagnostic interventions (e.g., CT or MRI) are more important to rule out secondary causes of seizures or to resolve uncertain diagnoses (e.g., video EEG) in a minority of selected patients. The monitoring interventions that may have an impact on outcomes are clinical/pharmacologic expertise, periodic blood tests (routine hematology and chemistries) for antiepileptic drug (AED)-related side effects, and possibly cognitive assessments in certain populations. Compliance with AED regimens predicts remission, but approaches to ensure compliance are not substantiated. Treatment interventions important for patients with a first diagnosis include clinical/pharmacologic expertise to inform choices of AED treatment, which are dictated more by differing side effect profiles than efficacy. Monotherapy AEDs appear comparable in efficacy for many epilepsy syndromes, but not all, for example juvenile myoclonic epilepsy, which require expertise not only to diagnose but to inform treatment choice.

The literature has multiple limitations, including lack of a universally accepted gold standard for diagnosis, low methodologic rigor, widespread terminology confusion, lack of patient-centered outcomes, including quality of life, health care utilization and costs, and gaps in coverage of virtually all nonclinical/pharmacologic treatment interventions in newly diagnosed patients.

The best available evidence from the literature is not conclusive regarding the appropriate and necessary diagnostic, monitoring, and treatment services for patients with newly diagnosed epilepsy. This literature review, however, can be used to generate testable hypotheses. We urge the health services research community to test these hypotheses in new and more rigorous studies in the future.

Ross SD, Estok R, Chopra S, et al. Management of Newly Diagnosed Patients with Epilepsy: A Systematic Review of the Literature. Evidence Report/Technology Assessment No. 39 (Contract 290-97-0016 to MetaWorks, Inc.) AHRQ Publication No. 01-E038. Rockville, MD: Agency for Healthcare Research and Quality. September 2001.

This project represents one phase of a multiphase task order nominated by the Centers for Disease Control and Prevention (CDC) to develop a framework for organizing the health care services necessary for providing optimal care to patients with low-prevalence, highly chronic conditions, in this case, epilepsy.

In this phase of the project, a clinical trial evidence base was developed through a systematic review of the literature pertinent to diagnostic, treatment, and monitoring interventions for patients with newly diagnosed epilepsy. Results have been qualitatively synthesized to provide an evidence-based evaluation of the health care services that contribute to optimal patient outcomes.

It is intended that this synthesis of the best available evidence will serve as an information resource for local decisionmakers and developers of practice guidelines and recommendations. It should also serve to highlight gaps in the literature and areas ripe for future research. Lastly, the approach to developing a matrix framework of patients and services, with a systematic review of the evidence addressing each patient-service intersect of the matrix, provides a useful model for assessing health care services for patients with other chronic conditions with relatively low prevalence.

What elements (expertise, services, and tests) may be needed to make the first diagnosis and initiate and monitor optimal treatment? What is the cumulative contribution (in order of increasing invasiveness and cost) of each of the following tests:
- Electroencephalogram (EEG) -- standard, ambulatory, video, invasive.
- Computed tomography (CT).
- Magnetic resonance imaging (MRI).
- Lumbar puncture.
- Blood tests.
What is the cumulative contribution (in order of increasing invasiveness and cost) to the accurate diagnosis of patients undergoing a first diagnosis? What is the positive and negative predictive value of each test alone? In what instances do additional tests add little useful information? Is there evidence to show that not applying particular tests will lead to incorrect diagnosis, negative health, or negative psychosocial outcomes? Are these tests useful for all patients undergoing first diagnosis or for only particular subpopulations? Which components of the patient's history are necessary to accurately diagnose the first seizure?
What criteria should be used to guide decisions about the timing and selection of treatments for patients undergoing first diagnosis?
Which interventions are necessary to adequately monitor patients on their first epileptic drug regimen or to ensure that the first diagnosis was correct? For what period of time should this monitoring occur? Should such monitoring be routine or prompted by particular symptoms/events?
What aspects of clinical/pharmacologic expertise have been demonstrated to result in optimal patient outcomes (maximum reduction of seizure frequency with minimal side effects)? Clinical/pharmacologic expertise is defined as: (a) selection of optimal antiepileptic drugs (AEDs) based on epilepsy diagnosis and patient characteristics, (b) adjusting drugs and dosages to reduce seizures, (c) monitoring and limiting adverse drug reactions and interactions, (d) monitoring patients' tolerance and compliance with particular drug regimens, (e) recognizing changes in seizure characteristics, and (f) ordering and interpreting appropriate laboratory tests based on knowledge of specific adverse events associated with different drugs.
What is necessary for patients at the time of first diagnosis in terms of social services, counseling (regarding, for example, employment or driving), or assistance and information from the Epilepsy Foundation? Is there evidence demonstrating that counseling improves patient followup, compliance, or quality of life?

This project was carried out in two phases. The first phase involved a stakeholder meeting at which a matrix framework of specific patient populations and health care interventions was developed. Literature citations were then broadly categorized according to the matrix of patients and interventions. In the second phase, all interventions (diagnostic, monitoring, and treatment) for a single population of interest (patients with newly diagnosed epilepsy) were chosen as the subject of a full systematic review. In general, MetaWorks investigators used systematic review methods derived from the evolving science of review research.

The review followed a prospective protocol that was developed a priori and shared with the nominating partner on the project (CDC), a panel of technical experts (with representation from consumer groups and health care providers in neurology, epileptology, primary care, and nursing), and the Task Order Officer at the Agency for Healthcare Research and Quality (AHRQ). The protocol outlined the methods to be used for the literature search, study eligibility criteria, data elements for extraction, and methodologic strategies to minimize bias and maximize precision during the process of data collection, extraction, and synthesis.

The published literature was searched in two phases corresponding to the two distinct phases of this project, ultimately covering the period from 1980 through December 1, 1999. MEDLINE was first searched as follows: (1) explode epilepsy and all treatment and human, and (2) explode epilepsy and diagnosis and human.

In the second phase of the project, another search was run in MEDLINE using the following sequence: (1) explode epilepsy, (2) human, (3) 1999, (4) diagnostic use (Medical Subject Heading, MeSH), (5) diagnosis, (6) therapy (MeSH), (7) therapeutic use, and (8) 4 or 5 or 6 or 7.

Review articles for the manual search were also identified in MEDLINE by searching back to 1996 by (1) explode epilepsy, (2) human, (3) diagnosis (MeSH), and (4) review (text word, TW).

Bibliographies of these reviews were perused for other likely citations. In addition, the 1999 Current Contents' CD-ROM was searched as: (1) epilepsy (key word, KW), (2) diagnosis (KW), (3) 1 and 2, (4) epilepsy (KW), (5) treatment (KW), (6) 4 and 5, (7) epilepsy (KW), (8) monitoring (KW), and (9) 7 and 8.

The Cochrane Library of Systematic Reviews was searched by (1) checking the Database of Systematic Reviews for epilepsy (KW) and, (2) checking the Database of Abstracts of Reviews of Effectiveness for epilepsy (KW).

All citations and abstracts were printed and screened at MetaWorks for any mention of patients with a first seizure, a first presentation, or a new diagnosis of epilepsy, for which full papers were obtained. The electronic searches noted above were supplemented by a search of the reference lists of all eligible studies and relevant review articles. To be included in the review, studies had to report results of any diagnostic, treatment, or monitoring intervention pertinent to newly diagnosed epilepsy in adults or children, with at least 10 patients as total sample size. Studies reported in English were accepted.

Each accepted study was extracted by one investigator and agreed to by a second. Key data elements sought for extraction from each study included study, patient, and intervention characteristics. In addition, for all diagnostic tests, sensitivity, specificity, and positive and negative predictive value, with its gold standard, were sought. All eligible papers were scored on features pertinent to study design, execution, and reporting, with a range of possible scores from 0.3 to 5.0.

No quantitative analyses were performed beyond descriptive statistics to summarize findings. Data were synthesized qualitatively. A group of 19 peer reviewers drawn from consumer groups and professional organizations, along with our technical experts and partners, was assembled to review and provide suggestions to the draft final report describing this project. Their feedback and that from AHRQ were incorporated wherever possible within the original scope of the project.

Of 13,128 citations, 120 studies -- mostly European and published in English since 1990 -- met all eligibility criteria. The study designs comprised 70 interventional and 50 observational studies. These studies covered 21,213 patients; all ages were represented, with balanced gender distribution and all major seizure types (generalized and partial).

No quantitative syntheses were possible because of insufficient and/or inconsistent reporting of results.

It is clear from this review of the literature addressing newly diagnosed patients that more research is needed to answer basic questions of diagnosis, monitoring, and treatment. This new research can be categorized as better studies and more studies. In the better studies category, we suggest the following:

All future diagnostic studies should measure and report sensitivity and specificity. This will require that a gold standard for diagnosis be agreed on. At this time, it seems this gold standard should be a clinical/EEG standard according to the latest International League Against Epilepsy (ILAE) classification scheme.
Treatment trials should use common terminology, e.g., distinguishing seizures from epilepsy and defining "newly diagnosed" in a common way, enrolling "pure" populations of patients with unprovoked seizures, and using common definitions of "optimum" outcomes inclusive of both seizures and side effects domains.
Treatment trials should use a core set of efficacy outcomes that are comparable across trials, e.g., seizure remission rates, time to recurrence, mean number of seizures per patient per unit of time, and time to remission.
Treatment trials need to report more often the efficacy, safety, and compliance associated with AEDs, in the long term.
All new trials should include "patient-centered" outcomes whenever appropriate, e.g., quality of life, health care utilization measures, and economic impact of interventions. Different research methods/designs may be required to optimally study these outcomes.

Studies relating the volume of practice (as a hypothesized surrogate for clinical/pharmacologic expertise) to patient outcomes. These would include studies of the consequences of delayed diagnosis or misdiagnosis.
Studies of the individual components of clinical/pharmacologic expertise to determine which of these components may or may not affect patient outcomes and which are related to volume of practice.
Studies based outside of academic epilepsy centers (e.g., community-based studies) that would better capture populations with new onset epilepsy and would include other caregivers besides academic neurologists.
Studies of the impact of patient counseling, education, and support interventions on patient outcomes.
Studies of the impact of both old and newer (e.g., Internet based) patient monitoring methods on patient outcomes.

Journal editors and reviewers should solicit and give preference to such studies, as well as raise the standard for the type of material acceptable for publication. More commentaries, opinions, narrative reviews, and anecdotes are not going to advance the field.