METHODS: From DANHEP, a national Danish HCV/HBV registry, and HCV Research UK (HCVRUK), a national HCV registry in the UK, we identified patients aged ≥18 years with HCV genotypes 1 or 4 initiating 2^nd and 1^stgeneration direct-acting antivirals (2GDAA and 1GDAA), dual therapy (DT), or no treatment (NT) between 2011-2014 (excluding clinical trial/early access programs). We describe HCV treatment strategy distributions and uptake for most recent treatment in both registries.

RESULTS: Between 2011-2014, 94.3% of DANHEP patients (N=1,988) were untreated vs. 82.1% in HCVRUK (N=4,301). NT patients in DANHEP were less likely to be previously treated (4.5% vs. DT 17.4%; 1GDAA 23.8%; 2GDAA 54.2%) and have cirrhosis (16.1% vs. DT 33.3%; 1GDAA 27.6%; 2GDAA 55.0%) but more likely to have HIV (10.5% vs. DT 10.0%; 1GDAA 6.9%; 2GDAA 7.5%). In HCVRUK, prevalence of HIV (NT 7.2%; DT 6.0%; 1GDAA 7.0%) and previous treatment (NT 46.4%; DT 20.1%; 1GDAA 48.7%) was similar among NT and 1GDAA patients but cirrhosis prevalence (NT 15.6%; DT 8.9%; 1GDAA 24.0%) was highest for 1GDAA patients. HCV treatment distribution (excluding NT) in DANHEP (N=113) was 20.4% DT, 37.2% 1GDAA, and 42.5% 2GDAA vs. 39.54% DT and 60.5% 1GDAA in HCVRUK (N=772). In 2011, 21.5% (14/65) of initiations in HCVRUK and 30.8% (8/26) of initiations in DANHEP were with 1GDAAs. By 2014, 98.0% (48/49) of initiations in DANHEP were with 2GDAAs and 42.9% (27/63) of initiations in HCVRUK were with 1GDAAs.   CONCLUSIONS: While new HCV treatment uptake was more rapid in Denmark and 2GDAAs were not available in the UK until 2015, prevalence of untreated HCV patients was higher in DANHEP than in HCVRUK. Motivation for withholding treatment may differ across countries.