At least 300,000 people were awaiting treatment for hepatitis C by the end of 2016 in the United States, with the lowest rates of treatment observed in the Upper Midwest, the Mountain states and the Pacific Northwest, according to a comprehensive review designed to capture information on who has been diagnosed and treated for hepatitis C in the US. The findings were published in advance online by the journal Advances in Therapy.
Just over half of those awaiting treatment already had stage F2 fibrosis or worse and 23% of all those awaiting treatment had F3 or F4 fibrosis. Delaying treatment until the onset of F3 or F4 fibrosis is associated with an increased risk of liver-related death, guidelines issued by the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America note. US guidelines recommend that everyone diagnosed with hepatitis C should be treated but some insurers still restrict reimbursement for treatment to people with advanced liver disease.
Based on a review of laboratory test data for around 914,000 people with hepatitis C, the study estimates that 94% of people treated for hepatitis C were cured in both 2015 and 2016.
The study sought to capture an overview of people with hepatitis C in the United States by compiling anonymised data provided by the two largest laboratory chains in the United States and by private and public health insurance providers including Medicare.
The authors say that the dataset captures the majority of hepatitis C virus (HCV) RNA tests carried out in the United States and so reflects the majority of people engaged in care. The dataset only includes people who were diagnosed or treated between 2013 and 2016 and may not capture people who were diagnosed prior to 2013 and who did not receive HCV RNA testing during this period. Between 2.7 million and 3.9 million people are estimated to have chronic hepatitis C infection in the United States but the US Centers for Disease Control estimated in 2012 that at least half of all chronic infections were undiagnosed.
The laboratory data enabled researchers to estimate the total number of people with chronic hepatitis C infection in care, the number of people undergoing treatment each year and the number of people cured of hepatitis C. More detailed clinical information including fibrosis stage, HIV status, laboratory measures of liver disease and kidney function could also be derived from laboratory records. This information was matched with age, gender and locational data.
The researchers used the intervals at which HCV RNA testing took place, and the results of those tests, to estimate the number of people treated and cured.
In total, the study identified 914,285 people who tested positive for HCV RNA between 2013 and 2016, indicating chronic infection. Of these, approximately 66,000 had been cured by the end of 2016. The odds of being treated and cured increased in each year from 2013 to 2016, most markedly in people aged 60 and over. This finding is probably explained by the prioritisation of screening of older age groups and the likelihood of more advanced liver disease in older people with hepatitis C.
In 2016, at least 308,000 people remained untreated and 89,020 started treatment.
The study found that almost 40% of people had some reduction in kidney function but less than 2% had reductions in kidney function likely to restrict their choice of treatment (chronic kidney disease stage 4 or 5).
The study also found that the only age group in which the total
number of untreated people grew between 2015 and 2016 was those
people aged 40 years or less. The authors say that this increase is at
least partially attributable to new infections as a result of heroin
use. Up to 70% of new HCV infections in under-40s in the United States
are attributable to injecting drug use, they point out.
The study was not able to show how long people wait for treatment but
did identify a slight decline in the total numbers of people in
greatest need of treatment still untreated in 2016. Whereas the number
of untreated people with stages F3 and F4 fibrosis fell in 2016 compared
to 2015, the number of people with F0 fibrosis grew, so that they
formed 30% of all untreated people in 2016.
The researchers say that their findings represent the biggest dataset on hepatitis C treatment and indicate improvements not only in cure rates but also in HCV RNA testing and staging of liver disease to enable treatment.