Prevalence and comorbidities of chronic hepatitis C: a nationwide population-based register study in Sweden.
OBJECTIVE
The aim of this study was to estimate the prevalence of physician-diagnosed and registered chronic hepatitis C (CHC), and to estimate the reported frequencies of Charlson comorbidities compared with matched comparators from the general population.


METHODS
Patients were identified according to ICD codes for CHC in the Swedish National Patient Register (1997-2013). Prevalence was estimated according to different patient identification algorithms and for different subgroups. Charlson comorbidities were ascertained from the same register and compared with age/sex/county of residence matched general population comparators.


RESULTS
A total of 34,633 individuals with physician-diagnosed CHC were alive in Sweden in 2013 (mean age, 49 years; 64% men), corresponding to a physician-diagnosed prevalence of 0.36%. The prevalence varied by case definition (0.22%-0.36%). The estimate dropped to 0.14% for monitored CHC disease (defined as ≥1 CHC-related visit in 2013). Overall, 41.3% of the CHC patients had ≥1 physician-registered Charlson comorbidity; the most common was liver diseases (22.1%). Compared with matched comparators from the general population (n = 171,338), patients with CHC had more physician-diagnosed and registered diseases such as chronic pulmonary disease (10.2% vs. 4.0%), diabetes (10.6% vs. 5.5%) and liver-related cancer (1.3% vs. 0.2%; all p < .01). No information on behavioural factors, such as smoking, alcohol consumption or on-going illicit drug use, was available.


CONCLUSIONS
The physician-diagnosed prevalence of CHC was slightly lower than previously reported estimates, and varied by case definition. The additional comorbidities observed in the CHC group should be taken into consideration, as these comorbidities add to the disease burden.
a AbbVie AB , Stockholm , Sweden.|b Department of Medicine , Karolinska Institutet , Stockholm , Sweden.|h Department of Laboratory Medicine, Division of Clinical Microbiology , Karolinska Institutet, Karolinska University Hospital , Stockholm , Sweden.
Katharina
K
Büsch
c Department of Infectious Medicine , Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg , Gothenburg , Sweden.
Jesper
J
Waldenström
c Department of Infectious Medicine , Institute of Biomedicine, Sahlgrenska Academy at the University of Gothenburg , Gothenburg , Sweden.
Martin
M
Lagging
d Department of Infectious Diseases , Karolinska Institutet, Karolinska University Hospital , Stockholm , Sweden.|e Department of Gastroenterology and Hepatology , Karolinska Institutet, Karolinska University Hospital , Stockholm , Sweden.
Soo
S
Aleman
f Department of Medicine Huddinge, Division of Infectious Diseases , Karolinska Institutet, Karolinska University Hospital , Stockholm , Sweden.
Ola
O
Weiland
a AbbVie AB , Stockholm , Sweden.
Jan
J
Kövamees
g Department of Infectious Diseases, Faculty of Medicine and Health , Örebro University , Örebro , Sweden.
Ann-Sofi
AS
Duberg
a AbbVie AB , Stockholm , Sweden.|h Department of Laboratory Medicine, Division of Clinical Microbiology , Karolinska Institutet, Karolinska University Hospital , Stockholm , Sweden.
Jonas
J
Söderholm
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000453:epidemiology*; D006801:Humans; D008113:Liver Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
Comorbidities; Sweden; hepatitis C; matched general population comparators; prevalence