People with hepatitis C have a much greater risk of
liver-related hospitalisation or death if they have an alcohol use disorder
or another serious co-morbidity such as HIV infection, chronic kidney disease or
cancer, according to an analysis of everyone hospitalised in France between
2008 and 2012. In the absence of these problems, people with hepatitis C did
not have an increased risk of death compared to the general population.
The findings were presented by Michael Schwarzinger of the
Translational Health Economics Network, Paris, at the International Liver
Congress in Vienna, Austria, on Saturday.
Previous research in smaller cohorts has shown that alcohol
use greatly increases the risk of liver-related death in people with hepatitis
C, but the French study is the largest study of the effects of alcohol on
liver-related clinical disease and death ever reported.
The study was designed to assess the contribution of various
confounding factors to the prognosis of people with hepatitis C infection. In
particular, the study sought to determine the extent to which alcohol might
contribute to the poor prognosis of hepatitis C infection – and whether people without high levels of alcohol
consumption have a poor prognosis if infected with hepatitis C.
The study could assess alcohol use only by physician report
of an 'alcohol use disorder', and the hospitals database does not contain any
information about average consumption, the definition of
alcohol misuse or the duration of heavy drinking. The diagnosis of alcohol use
disorder covers a spectrum of problematic drinking, ranging from regular
over-indulgence to severe physical
dependence, and is classified as mild, moderate or severe. The
appearance of alcohol use disorder on a medical record is therefore a red
flag that someone has a history of high alcohol consumption, but can provide no
information that can be used to calculate less harmful levels of consumption or
how many years of heavy drinking might negatively affect the prognosis of
people with hepatitis C.
The study also looked at the contribution of serious
co-morbidities to the need for hospitalisation for liver-related events.
During the period 2008-2012, 28,953,755 people in
France were admitted to hospital and 1,506,453 people died in hospital. Chronic infection with hepatitis C virus (HCV) was
present in 112,146 (0.39%) of hospitalised patients, alcohol use disorder in 705,259 (2.44%), and
both chronic HCV infection and alcohol use disorder in 23,351 (i.e., 20.8% alcohol use disorder recorded in people with hepatitis C).
The analysis found that people with hepatitis C were six times
more likely to have an alcohol use disorder than other hospital patients,
and 2.4 times more likely to have at least one serious co-morbidity.
Forty-six per cent of all liver-related events in people
with hepatitis C occurred in those with alcohol use disorders, approximately
one-third in people with at least one serious co-morbidity, and only 14% in
people with hepatitis C who had neither a co-morbidity nor an alcohol use
disorder.
The study also found that people in the general population
had a much worse prognosis than others if they had an alcohol use disorder.
They were three times more likely to die in hospital than people who did not
drink alcohol.
The poor prognosis of people with hepatitis C is largely
explained by alcohol misuse and by severe co-morbidities, Schwarzinger
told a
press conference. The findings call into question the cost-effectiveness
of
direct-acting antiviral treatment for hepatitis C for people without
alcohol use disorders, he went on, because rates of progression and
consequent
medical costs averted by immediate treatment may be much lower than
current
models suggest.
“These results show that alcohol
use disorders are a much more accurate indicator of mortality in chronic HCV
infection, and highlight the need to encourage alcohol withdrawal and
abstinence in all patients,” said Professor Tom Hemming Karlsen,
Scientific Committee Member, European Association for the Study of the Liver (EASL).
People
who had stopped drinking or who had remained abstinent had a one-third
reduction in the risk of death compared to people who drank any alcohol, while
in the general population abstinence or
withdrawal reduced the risk of death by one quarter.
Schwarzinger
said that the effect of alcohol abstinence and withdrawal should be
investigated more closely in people with hepatitis C. For example, the better prognosis of people
with genotype 4 hepatitis C may be a consequence of its epidemiology – genotype
4 is prevalent in Muslim countries in North Africa and the Middle East where
alcohol consumption is culturally unacceptable – rather than any feature of the
genotype, Schwarzinger argued.