Liver mortality attributable to chronic hepatitis C virus infection in Denmark and Scotland: Using spontaneous resolvers as the benchmark comparator

TY - JOUR

T1 - Liver mortality attributable to chronic hepatitis C virus infection in Denmark and Scotland

T2 - Using spontaneous resolvers as the benchmark comparator

AU - Innes, Hamish

AU - Hutchinson, Sharon J

AU - Obel, Niels

AU - Christensen, Peer B.

AU - Aspinall, Esther J

AU - Goldberg, Michael David

AU - Krarup, Henrik

AU - McDonald, Scott A

AU - McLeod, Allan

AU - Weir, Amanda

AU - Omland, Lars H

N1 - © 2016 by the American Association for the Study of Liver Diseases.

PY - 2016/5/1

Y1 - 2016/5/1

N2 - Liver mortality among individuals with chronic hepatitis C (CHC) infection is common, but the relative contribution of CHC per se versus adverse health behaviors is uncertain. We explored data on spontaneous resolvers of hepatitis C virus (HCV) as a benchmark group to uncover the independent contribution of CHC on liver mortality. Using national HCV diagnosis and mortality registers from Denmark and Scotland, we calculated the liver mortality rate (LMR) for persons diagnosed with CHC infection (LMRchronic) and spontaneously resolved infection (LMRresolved), according to subgroups defined by age, sex, and drug use. Through these mortality rates, we determined subgroup-specific attributable fractions (AFs), defined as (LMRchronic - LMRresolved)/LMRchronic, and then calculated the total attributable fraction (TAF) as a weighted average of these AFs. Thus, the TAF represents the overall fraction (where 0.00 = not attributable at all; and 1.00 = entirely attributable) of liver mortality attributable to CHC in the diagnosed population. Our cohort comprised 7,005 and 21,729 persons diagnosed with HCV antibodies in Denmark and Scotland, respectively. Mean follow-up duration was 6.3-6.9 years. The TAF increased stepwise with age. It was lowest for death occurring at <45 years of age (0.21 in Denmark; 0.26 in Scotland), higher for death occurring at 45-59 years (0.69 in Denmark; 0.69 in Scotland), and highest for death at 60+years (0.92 in Denmark; 0.75 in Scotland). Overall, the TAF was 0.66 (95% confidence interval [CI]: 0.55-0.78) in Denmark and 0.55 (95% CI: 0.44-0.66) in Scotland. Conclusions: In Denmark and Scotland, the majority of liver death in the CHC-diagnosed population can be attributed to CHC-nevertheless, an appreciable fraction cannot, cautioning that liver mortality in this population is a compound problem that can be reduced, but not solved, through antiviral therapy alone.

AB - Liver mortality among individuals with chronic hepatitis C (CHC) infection is common, but the relative contribution of CHC per se versus adverse health behaviors is uncertain. We explored data on spontaneous resolvers of hepatitis C virus (HCV) as a benchmark group to uncover the independent contribution of CHC on liver mortality. Using national HCV diagnosis and mortality registers from Denmark and Scotland, we calculated the liver mortality rate (LMR) for persons diagnosed with CHC infection (LMRchronic) and spontaneously resolved infection (LMRresolved), according to subgroups defined by age, sex, and drug use. Through these mortality rates, we determined subgroup-specific attributable fractions (AFs), defined as (LMRchronic - LMRresolved)/LMRchronic, and then calculated the total attributable fraction (TAF) as a weighted average of these AFs. Thus, the TAF represents the overall fraction (where 0.00 = not attributable at all; and 1.00 = entirely attributable) of liver mortality attributable to CHC in the diagnosed population. Our cohort comprised 7,005 and 21,729 persons diagnosed with HCV antibodies in Denmark and Scotland, respectively. Mean follow-up duration was 6.3-6.9 years. The TAF increased stepwise with age. It was lowest for death occurring at <45 years of age (0.21 in Denmark; 0.26 in Scotland), higher for death occurring at 45-59 years (0.69 in Denmark; 0.69 in Scotland), and highest for death at 60+years (0.92 in Denmark; 0.75 in Scotland). Overall, the TAF was 0.66 (95% confidence interval [CI]: 0.55-0.78) in Denmark and 0.55 (95% CI: 0.44-0.66) in Scotland. Conclusions: In Denmark and Scotland, the majority of liver death in the CHC-diagnosed population can be attributed to CHC-nevertheless, an appreciable fraction cannot, cautioning that liver mortality in this population is a compound problem that can be reduced, but not solved, through antiviral therapy alone.

KW - Adult

KW - Aged

KW - Antiviral Agents

KW - Benchmarking

KW - Denmark

KW - Female

KW - Health Behavior

KW - Hepatitis C, Chronic

KW - Humans

KW - Male

KW - Middle Aged

KW - Scotland

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1002/hep.28458

DO - 10.1002/hep.28458

M3 - Journal article

C2 - 26773546

SN - 0270-9139

VL - 63

SP - 1506

EP - 1516

JO - Hepatology

JF - Hepatology

IS - 5

ER -