Inhibitory Control Test and Lactulose saves more than $3 Million over 5 years
A late stage liver condition, known as minimal hepatic encephalopathy
(MHE), is associated with impaired driving skills and greater risk of
motor vehicle accidents. Cost analysis of management strategies for
detection and treatment of MHE are published in the April issue of Hepatology,
a journal of the American Association for the Study of Liver Diseases.
Findings report that MHE diagnosis using the inhibitory control test
followed by treatment with lactulose was the most cost-effective
approach--preventing the most car accidents and reducing societal cost
by up to $3.6 million over a 5-year period.
In cirrhosis, as the liver fails, the build-up of toxic substances
normally removed by the liver can lead to MHE—a reversible condition
that causes cognitive impairment and loss of consciousness. Medical
evidence reports that MHE is present in 55% of cirrhotic patients
tested, and is associated with higher risk of motor vehicle collisions
due to attention and visuomotor coordination deficits. The Inhibitory
control test measures an individual’s attention and experts suggest it
could be cost-effective in diagnosing MHE and correlates with driving
impairments.
Previous research estimates vehicular accidents cost more than $200
billion per year in the U.S. in terms of lost productivity, medical
costs, automobile damage, and insurance expenses. “Detection and
treatment of MHE has potential to reduce costs and morbidity related to
car accidents,” explains lead study author Dr. Jasmohan Bajaj with
McGuire VA Medical Center and Associate Professor at Virginia
Commonwealth University School of Medicine. “Our study analyzes the
cost-effectiveness of various strategies for diagnosing and treating MHE
to reduce vehicular accidents and the societal cost burden.”
Researchers compared five strategies for managing MHE that included
presumptive treatment of all cirrhotic patients; diagnosis by
neuropsychological exam with therapy; psychometric diagnostic testing
with treatment; diagnosis using inhibitory control test with treatment;
and no MHE diagnostics or treatment. Analysis was conducted on a
simulated group of 1,000 cirrhotic patients treated for MHE with
lactulose or rifaximin, and followed for 5 years. Researchers estimated
the societal cost of a single car accident to be $42,100.
Results show the cost per motor vehicle accident prevented by diagnosing
MHE with the inhibitory control test was $24,454; standard psychometric
tests was $25,470; with presumptive treatment it was $30,469; and with
neuropsychological exam the cost was $33,742. “Our findings provide
strong evidence that detection of MHE, particularly the inhibitory
control test, and subsequent treatment with lactulose reduces societal
costs by preventing motor vehicle accidents in patients with MHE,”
concludes Dr. Bajaj.
The authors of a related editorial also published in this month’s issue
cite previous research that reports driving errors account for 71% to
98% of all motor vehicle accidents. They suggest that the high
percentage of traffic accidents involving driver error makes the
assessment of driving abilities crucial for patients with MHE. The study
by Bajaj et al. provides evidence which may encourage further real-life
effect of MHE on accident rates, and according to the authors, raise
awareness of the implications for patients with liver disease and the
whole of society.
