Only 15% of US veterans have been tested for hepatitis B virus (HBV)
infection, and among those who tested positive just one-quarter received
antiviral treatment and 13% were screened for liver cancer – although both
measures were shown to reduce the risk of death – researchers reported on Sunday at the American Association for the Study of Liver
Diseases (AASLD) Liver Meeting in Boston, United States.
Marina Serper and colleagues from the Philadelphia Veterans Affairs (VA)
Medical Center and the University of Pennsylvania aimed to identify gaps in
recommended hepatitis B care in the US.
An estimated 1.25 million people are infected with HBV in the US, the
researchers noted as background. While the AASLD and other professional groups
have established guidelines for testing, care and treatment, studies suggest
these are not routinely followed.
The Veterans Health Administration is the largest provider of hepatitis
care in the US, and its centralised care and data collection facilitates
analysis of procedures and outcomes in the absence of a national health system.
However, the veteran population does not reflect the American population as a
whole.
The researchers
conducted a retrospective cohort analysis using data from the Corporate Data Warehouse, a national database containing claims,
clinical data, pharmacy records and death records, during the period 1999
through 2013.
Out of 16,718,682
individuals with at least two visits to VA health facilities, a total of
2,533,862 – or 15% – had a record of being tested for hepatitis B surface
antigen (HBsAg). Among those who were tested, 21,828 individuals – or 0.9% –
were found to be HBsAg-positive. (People who died within one week of receiving
a positive HBsAg test were excluded from further analysis.)
HBsAg positivity is the usual method of determining whether
someone currently has hepatitis B. People may have anti-HBV antibodies due to
either vaccination or having naturally cleared a previous infection (which
occurs in more than 90% of people infected as adults). Therefore, HBsAg is a better
indication of who is eligible for hepatitis B care and treatment.
In
the HBsAg-positive
group, most were men (typical of a veteran population) and the median
age was
52 years. About half were white, 41% were African-American, 5.4% were
Asian and
2.4% were American Indian or Native Hawaiian. Nearly one-fifth (17%)
also had hepatitis C virus and 4.7% had HIV co-infection. Nearly 40%
had a record of significant alcohol use and 8.3% had diagnosed liver
cirrhosis.
One-third had alanine aminotransferase (ALT) levels at least twice the
upper
limit of normal, suggesting active liver inflammation.
A total of 6744
veterans with hepatitis B – or 31% – were referred for specialty care. Looking
at laboratory testing, overall 73% had received ALT tests, 26% received HBV DNA
viral load tests, 40% were tested for hepatitis B 'e' antigen (HBeAg, a marker
for viral replication and a predictor of treatment response), 46% were tested
for hepatitis B 'e' antibodies, 42% were tested for hepatitis A and 7.9% were
tested for hepatitis D or delta (a defective virus that only occurs with HBV
and can lead to more severe liver disease). Among people referred to specialty
care, testing rates improved significantly, to 99%, 59%, 65%, 73%, 73% and 15%,
respectively.
Regarding other types
of care, only 1.8% of all HBsAg-positive people and 3.0% of those in specialty
care received recommended hepatitis A vaccinations (after excluding about 5400
people who were already immune due to vaccination or prior naturally cleared
infection).
One-quarter received
antiviral treatment for hepatitis B, rising to 38% among those with elevated
ALT. For people in specialty care, treatment rates were 44% and 49%, respectively.
Screening for
hepatocellular carcinoma (HCC, a type of primary liver cancer) is recommended
for people with active hepatitis B, especially those with cirrhosis. Yet only
13% of HBsAg-positive patients overall, and 18% of those in specialty care,
received HCC screening. These figures excluded nearly 8700 people under the
age of 50 – as HCC usually occurs in older people with long-term disease
progression – though many experts believe younger at-risk people should be
screened as well.
Turning to clinical
outcomes, the overall incidence of liver cancer was 4.5 cases per 1000
person-years. The rate was 3.7 per 1000 person-years among people referred
to specialty care compared with 7.1 per 1000 person-years among those not
receiving such care – a significant risk reduction of about 50% (IRR 0.52%).
The overall rate of
hepatic decompensation, or liver failure, was 8.4 cases per 1000 person-years.
Here, the rate was higher among people in specialty care (14.3 vs 6.7 per 1000
person-years, respectively), which may indicate that people with more advanced
disease were more likely to get special care. However, all-cause mortality
rates for patients with and without specialty care (36.0 vs 37.7 per 1000
person-years, respectively) did not differ significantly (IRR 1.05).
A multivariate
analysis of predictors of mortality found that HCC screening was associated
with a 20% reduction in the risk of death during 2000-2010 and a 36% reduction
during 2010-2013 (HR 0.80 and 0.64). Antiviral therapy had a smaller effect,
reducing mortality risk by 4% during 2000-2010 and by 17% during 2010-2013,
with only the later period being statistically significant (HR 0.96 and 0.83).
Based on these
findings, the researchers concluded that there are "significant gaps in
recommended HBV care in the US." They recommended that clinical decision
support tools should be developed to improve guidelines adherence and clinical
outcomes in people with hepatitis B.