Deaths in the US due to hepatitis C now
exceed those caused by HIV, according to research published in the Annals of Internal Medicine. The study showed that there is a downward
trend in HIV-related mortality, but incidence of deaths due to hepatitis C is
increasing.
“This analysis shows the rapidly increasing
number of deaths among HCV [hepatitis C virus]-infected persons, which now
surpass deaths among HIV-related persons,” write the authors.
Mortality was concentrated in the “baby
boomer” generation, individuals aged between 45 to 64 years. The investigators
believe this pattern “portends a large and ever-increasing health care burden.”
Glossary
- QALY
Quality adjusted life year. Used in studies dealing with cost-effectiveness and life expectancy, this gives a higher value to a year lived with good health than a year lived with poor health, pain or disability.
The majority of hepatitis C infections in
the US are undiagnosed and a separate study published in the same journal shows
that targeted hepatitis C screening of individuals in this age group would be
cost-effective and could avert up to 121,000 deaths compared to current
risk-based screening.
Infection with hepatitis B and hepatitis C
are leading causes of chronic liver disease and liver cancer in the US. In
2007, they were listed among the 15 leading causes of death.
Investigators used information recorded on
death certificates to plot trends in mortality due to hepatitis B and hepatitis
C between 1999 and 2007. These trends were compared to the incidence of
HIV-related deaths over the same period. Analysis was also undertaken to
determine the factors associated with hepatitis-related deaths in 2007.
Approximately 21.8 million death
certificates were included in the investigators’ analysis.
There was a non-significant decrease in hepatitis
B-related mortality of 0.02 deaths per 100,000 person years. However, the
incidence of hepatitis C-related deaths increased by a significant 0.18 per
100,000 person years (p = 0.002). This compared to a reduction in HIV-related
mortality of 0.21 per 100,000 person years (p = 0.001). Indeed, in 2007
mortality associated with hepatitis C infection surpassed that from HIV
infection.
Hepatitis B was documented as the
underlying cause of 724 deaths (0.03%) and as the single underlying or
contributing cause in 1815 deaths (0.07%; adjusted mortality rate, 0.56 deaths
per 100,000 person years).
Infection with hepatitis C virus was
documented as the underlying cause of 6605 deaths (0.27%) and as the underlying
or contributing cause of 15,106 deaths (0.62%; adjusted mortality rate, 4.58
deaths per 100,000 person years).
This hepatitis C-related mortality exceeded
that attributed to HIV. Infection with HIV was listed as the underlying cause
of death on 11,332 death certificates (0.47%), and the underlying or
contributory cause in 12,734 deaths (0.52%; adjusted mortality rate, 4.16
deaths per 100,000 person years).
The investigators believe that these data
grossly underestimate the true burden of hepatitis C-related mortality. “HCV
infection and HCV-related chromic liver disease have remained consistently
poorly ascertained and, thus, under-reported on death certificates.”
A number of co-morbid conditions were
strongly related to death attributed to hepatitis B. These included chronic
liver disease (AOR = 34.4; 95% CI, 31.0-38.1), co-infection with hepatitis C
(AOR = 31.5; 95% CI, 28.0-35.4), HIV infection (AOR = 4.0; 95% CI, 3.2-5.1) and
alcohol-related illness (AOR = 3.7; 95% CI, 3.2-4.2).
Co-morbid conditions related to hepatitis C
mortality were chronic liver disease (AOR = 32.1; 95% CI, 31.0-33.3),
co-infection with hepatitis B (AOR = 29.9; 95% CI, 26.5-33.6), alcohol-related
illness (AOR = 4.6; 95% CI, 4.4-4.8) and HIV co-infection (AOR = 1.8; 95% CI,
1.6-2.0).
Deaths attributable to viral hepatitis
infection were clustered in the “baby boomer” generation, individuals born
between 1945 and 1964. In all, 59% of hepatitis B-related deaths were involved persons
aged between 45 and 64 years as did 73% of deaths attributed to hepatitis C.
“Few diseases of such morbidity and
mortality in the United States have received so little public attention and
funding as chronic viral hepatitis,” comment the authors.
Current screening strategies are
risk-based, targeting individuals with a history of injecting drug use. The
investigators suggest this has been “notably unsuccessful, as few have been
screened for risk and are still only tested when they have symptoms…few
physicians ask about the major risk factor for HCV, injecting drug use, and few
interviewees wish to admit this behavior.”
Because almost 75% of hepatitis C-related
deaths involved individuals aged between 45 and 64 the researchers suggest
“screening efforts that target middle-aged persons may be profitable.”
A second study published in the same
edition of the Annals showed that
such a strategy could be cost-affect and save tens of thousands of lives.
Researchers wanted to ascertain the
effectiveness, benefits and cost of three approaches to hepatitis C screening
and treatment. These were:
Model 1: Risk-based screening,
and hepatitis C therapy including pegylated interferon and ribavirin.
Model 2: Age-based screening
(45 to 64 years) in routine care, with hepatitis C treatment with pegylated
interferon and ribavirin.
Model 3: Age-based testing, and
hepatitis C triple hepatitis C therapy including a protease inhibitor,
pegylated interferon and ribavirin.
The authors calculated that 2.4 million
hepatitis C-infected individuals had a primary care consultation in 2006 and
that 50% of these infections were undiagnosed.
Risk-based screening would lead to 135,000
patients receiving hepatitis C therapy, which would be successful for 53,000
patients. A total of 592,000 patients would die of liver-related causes.
Screening based on age would identify
1,070, 840 infections. An estimated 552,000 patients would receive treatment
with pegylated interferon and ribavirin and 229,000 would be cured of their
infection. Compared to the risk-based strategy, 82,000 deaths would be averted
compared to risk-based testing. The cost of this age-based screening with
standard two-drug treatment was $15,700 per QALY compared with risk-based
screening.
The addition of a protease inhibitor would
increase the number of patients achieving a cure to 311,000, averting 121,000
deaths compared to screening based on risk. The estimated cost was $35,700 per
QALY gained. The cost of this strategy was equivalent “to cervical cancer or
cholesterol screening.”
The authors therefore conclude,
“birth-cohort screening seems to be a reasonable strategy to identify
asymptomatic cases of HCV.”