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Physicians May Use
Risk-Based Screening
Strategy to Identify
Hepatitis C Virus
Infection
Laurie Barclay, MD
June 2, 2010 — In a
high-risk, urban
ambulatory care setting,
physicians may use a
risk-based screening
strategy to test for
hepatitis C (HCV)
infection, according to
the results of a study
published online May 20
in the Journal of Viral
Hepatitis. This was the
first of several studies
from the US Centers for
Disease Control (CDC)
testing the
effectiveness of current
and alternative HCV
screening strategies.
"Approximately 3.2
million persons are
chronically infected
with [HCV] in the U.S.;
most are not aware of
their infection," write
William N. Southern, MD,
from Albert Einstein
College of Medicine of
Yeshiva University,
Bronx, New York, and
colleagues. "Our
objectives were to
examine HCV testing
practices to determine
which patient
characteristics are
associated with HCV
testing and positivity,
and to estimate the
prevalence of HCV
infection in a high-risk
urban population."
Participants consisted
of all patients enrolled
in the baseline phase of
the Hepatitis C
Assessment and Testing
Project, which is a
serial, cross-sectional
study examining
screening strategies for
HCV. All participants
were examined from
January 1, 2008, to
February 29, 2008,
during a clinic visit to
Montefiore Medical
Center. The
investigators determined
demographic factors,
results of laboratory
testing, and
International
Classification of
Diseases, 9th Edition,
diagnostic codes from
March 1, 1997, to
February 29, 2008, using
electronic medical
records.
Birth date;
International
Classification of
Diseases, 9th Edition,
codes; and laboratory
results data were used
to define risk factors
for HCV. To estimate the
prevalence of HCV
infection, the
investigators assumed
that untested subjects
would test positive at
the same rate as tested
subjects, based on risk
factors.
HCV testing was
performed in 3803
(39.7%) of 9579
participants evaluated.
Of these, 438 (11.5%)
were positive, yielding
an estimated overall
prevalence of HCV
infection of 7.7%, which
is nearly 5 times higher
than the estimated
national prevalence of
1.6%. The study authors
also estimated that more
than 40% of HCV-positive
persons were unaware of
their status.
Risk factors identified
as being associated with
being tested and having
a positive HCV testing
result were:
-
birth date from 1945
to 1964 (the
high-prevalence
birth cohort),
-
substance abuse,
-
HIV infection,
-
alcohol abuse,
-
diagnosis of
cirrhosis,
-
end-stage renal
disease, and
-
high alanine
transaminase levels.
"In a high-risk urban
population, a
significant proportion
of patients were tested
for HCV and the
prevalence of HCV
infection was high," the
study authors write.
"Physicians appear to
use a risk-based
screening strategy to
identify HCV infection."
Limitations of this
study include that not
all patients were tested
for anti-HCV and,
therefore, an estimated
prevalence was used; the
use of an electronic
medical record for data
collection, preventing
capture of all risks for
HCV infection for each
patient; and failure to
consider the temporal
relationship between
risk factors and HCV
tests, which means that
certain risk factors (eg,
substance abuse) may
have been identified
after the HCV diagnosis
was made. Nonetheless,
"a strong relationship
between high risk
co-morbidities and
physician testing
behaviour" was
uncovered.
"We found strong
evidence that physicians
are using a risk-based
screening strategy to
identify patients with
HCV infection, using
known risk factors and
other conditions
associated with HCV to
guide testing," the
study authors conclude.
"We also found evidence
that screening
recommendations should
be expanded to include
the high prevalence
birth cohort."
This project was
supported by a US
Centers for Disease
Control and Prevention
contract via the Agency
Health Care Research and
Quality ACTION
initiative to Boston
University, the Clinical
Investigation Core of
the Center for AIDS
Research at the Albert
Einstein College of
Medicine and Montefiore
Medical Center, the
National Institutes of
Health and the CTSA from
the National Center for
Research Resources, a
component of the
National Institutes of
Health. Two of the study
authors are Centers for
the Disease Control and
Prevention employees,
and one is an employee
of Emerging Health
Information
Technologies. Some of
the study authors report
various financial
relationships with Roche
Pharmaceuticals, Vertex
Pharmaceuticals, Sanofi
Aventis, and/or DiMagi,
Inc.
J Viral Hepatitis.
Published online May 20,
2010
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