Publications & Reports

Adherence to once-daily and twice-daily direct acting antiviral therapy for hepatitis C infection among people with recent injection drug use or current opioid agonist therapy.

Cunningham EB, Hajarizadeh B, Amin J, Litwin AH, Gane E, Cooper C, Lacombe K, Hellard M, Read P, Powis J, Dalgard O, Bruneau J, Matthews GV, Feld JJ, Dillon JF, Shaw D, Bruggmann P, Conway B, Fraser C, Marks P, Dore GJ, Grebely J
The Kirby Institute, UNSW Sydney, Sydney, Australia.


BACKGROUND: This study investigated treatment adherence and associated factors among people with recent injecting drug use or current opioid agonist therapy (OAT) and compared once-daily to twice-daily DAA therapy. METHODS: SIMPLIFY and D3FEAT are international, multicentre studies which recruited participants with recent injecting drug use (previous six months; SIMPLIFY, D3FEAT) or current OAT (D3FEAT) between March 2016 and February 2017 in eight countries. Participants received sofosbuvir/velpatasvir (once-daily; SIMPLIFY) or paritaprevir/ritonavir/ombitasvir, dasabuvir (twice-daily) +/-ribavirin (D3FEAT) for 12 weeks administered in electronic blister-packs. We evaluated overall adherence (proportion of prescribed doses taken) and non-adherence (<90% adherent) with comparisons between dosing patterns. RESULTS: Of 190 participants who commenced treatment, 184 (97%) completed treatment. Median adherence was 92% with higher adherence among those receiving once-daily vs. twice-daily therapy (94% vs. 87%, P=0.005). Overall, 40% of participants (n=76) were considered non-adherent (<90% adherent). Recent stimulant injecting (odds ratio [OR] 2.48, 95% confidence interval [CI] 1.28-4.82), unstable housing (OR 2.18, 95% CI 1.01-4.70), and receiving twice-daily dosing (OR 2.81, 95% CI 1.47-5.36) were associated with non-adherence. Adherence decreased over the course of therapy SVR was high in non-adherent (89%) and adherent populations (95%, P=0.174) with no difference in SVR between those who did and did not miss at least seven consecutive doses (92% vs 93%, P=0.897). CONCLUSION: This study demonstrated high adherence to once- and twice-daily HCV DAA therapy among people with recent injecting drug use or were currently receiving OAT. The levels of non-adherence described did not impact treatment outcomes, suggesting forgiveness to non-adherence.

Link to publisher’s web site


  • Journal: Clinical Infectious Diseases
  • Published: 01/01/2020
  • Volume: 71
  • Issue: 7
  • Pagination: E115-E124