Biomedical Engineering Reference
In-Depth Information
ficity, as different thresholds (cut points) are used to differentiate between positive
and negative tests, for example, between response and nonresponse to a treatment.
11.2.4 Pragmatic Evaluation of Candidate Biomarkers
Given the potential for improving care and the pitfalls that may await possible
biomarkers, how then can we judge a biomarker for use in psychiatric management?
Table 11.2 summarizes some key, desirable characteristics of psychiatric
biomarkers. Many of them follow directly from the pitfalls just detailed, but the last
three on the list merit special mention.
First, the information provided by the biomarker must be timely, clinically use-
ful, and cost effective. A test that is able to predict 8-week treatment response at
week 5 is much less clinically valuable than a test making the prediction at week 1. A
biomarker that identifies an individual with a treatment-refractory illness is some-
what less useful than one that points the way to an alterative treatment strategy. It is
unlikely that the field would adopt a biomarker that consumes more resources than
it saves, either in direct expenses or by wrongly suggesting pursuit of an ineffective
treatment.
Second, the technology needed to assess the biomarker must be available and
well tolerated by the target patient population. For example, some neuroimaging
methods may be very well suited to neuroscience research applications, in which a
small number of subjects can be observed with great detail. From a broader perspec-
tive, though, if the scanning technology costs too much to be deployed widely in the
community, the method may not come to be translated into practice. Similarly, a
procedure that is perceived by patients as painful (e.g., lumbar puncture) or chal-
lenging (e.g., a prolonged scanning procedure requiring immobility) may have low
penetration into the clinical arena for reasons of practicality.
Third, methods that can be seamlessly integrated into existing clinical care prac-
tice patterns are more likely to be accepted than those that require major shifts in the
delivery of care. For example, sending a patient to a different facility for a biomarker
procedure and waiting for test results for a day or two is less desirable than being
able to perform a test in one's office or ward.
To summarize, qEEG-based biomarkers have great potential for improving the
care of patients with psychiatric disorders, much as other biomarkers have in other
medical specialties. Adoption of biomarkers into clinical care, however, requires
careful and thorough evaluation, and there is risk to patients if measures are
Table 11.2
Desirable Characteristics of Biomarkers in Psychiatry
Test reliability, accuracy, and limitations are well characterized.
Biomarker development process is clearly disclosed.
Findings are reproducible with independent replication and peer review.
Interpretative framework for the biomarker allows comparison with other
neurobiological observations.
Information provided by the biomarker is timely, clinically useful, and cost effective.
Technology is available and well tolerated by target patient population.
Methodology can be integrated into clinical care practice patterns.
Search WWH ::
Custom Search