Abstract
Background
Adequate medication adherence is critical for achieving sustained viral response (SVR) of hepatitis C virus (HCV) among people who inject drugs (PWID). However, it is less known which patterns of direct-acting antiviral (DAA) treatment adherence are associated with SVR in this population or what factors are associated with each pattern.
Methods
The randomized three-arm PREVAIL study utilized electronic blister packs to obtain daily time frame adherence data in opiate agonist therapy program settings. Exact logistic regressions were applied to test the associations between SVR and six types of treatment adherence patterns.
Results
Of the 113 participants treated with combination DAAs, 109 (96.5%) achieved SVR. SVR was significantly associated with all pattern parameters except for number of switches between adherent and missed days: total adherent daily doses (exact AOR=1.12; 95%CI=1.04-1.22), percent total doses (1.09; 1.03-1.16), days on treatment (1.16; 1.05-1.32), maximum consecutive adherent days (1.34; 1.06-2.04), maximum consecutive non-adherent days (.85; .74-.95=.003). SVR was significantly associated with total adherent doses in the first two months of treatment, it was not in the last month. Compared to White participants (30.7±11.8(se)), Black (18.4±7.8) and Hispanic participants (19.2±6.1) had significantly shorter maximum consecutive adherent days. While alcohol intoxication was significantly associated with frequent switches, drug use was not associated with any adherence pattern.
Conclusion
Consistent maintenance of adequate total dose adherence over the entire course of HCV treatment is important in achieving SVR among PWID. Additional integrative addiction and medical care may be warranted for treating PWID experiencing alcohol intoxication.
A qualitative study trialling the acceptability of new hepatitis C prevention messages for people who inject drugs: symbiotic messages, pleasure and conditional interpretations
