Influence of treatment complexity on adherence and incidence of blips in HIV/HCV coinfected patients.

Background: The addition of antihepatitis C therapy to highly active antiretroviral treatment (HAART) in human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfected patients leads to an increase in the treatment complexity that may result in decreased adherence. Blips, defined as intermittent episodes of detectable low-level HIV viremia, may be an indication of poor adherence to HAART.

Objectives: To (a) determine the influence of adding anti-HCV therapy to HAART on complexity index, adherence, and incidence of blips and (b) determine complexity index and adherence in patient subgroups based on anti-HCV therapy.

Methods: We conducted a prospective 2-center observational study. HIV/HCV coinfected patients under antiretroviral treatment who started anti-HCV bi-therapy or triple therapy between January 2011 and December 2013 were included. Patients were excluded if they were virologically uncontrolled (HIV viral load greater than 50 copies RNA/mL) or if they had changed antiretroviral treatment in the 6 months prior to the introduction of anti-HCV therapy. Data were collected before and after the addition of anti-HCV therapy to HAART. The main variables were complexity index, incidence of blips, and adherence. The complexity index was based on a score that utilized the number of pills per day, dosing schedule, dosage form, and any specific instructions linked to use of the drug. Blips were defined as a detectable HIV-RNA level ( greater than 50 copies/mL but no more than 1,000 copies/mL) occurring between 2 negative assays. Medication adherence was assessed using electronic pharmacy refill records. The threshold for optimal adherence was defined at 95% and above. Differences in the variables collected were assessed before and after the addition of anti-HCV therapy to HAART.R ESULTS: A total of 66 patients were included in the study. Based on the complexity index, the median value before and after the addition of anti-HCV therapy to HAART was 4.2 (interquartile range [IQR] = 3.5-5.5) and 11.5 (IQR = 10.4-13.4), respectively. The median difference between both complexity indices was 6.9 (95% CI = 6.9-7, P  less than  0.001). After introducing the anti-HCV therapy into HAART, the number of adherent patients decreased from 50 (75.8%) to 45 (68.2%, P  greater than 0.05), and 12 (18.2%) patients presented blips (P  less than  0.001). Subgroup analysis based on anti-HCV therapy showed that patients on boceprevir or telaprevir therapy had a higher complexity index, 16.8 (IQR = 6.0-18.4), compared with patients on bi-therapy anti-HCV, 11.3 (IQR = 10.3-12). The median difference was 6.0 (95% CI = 5.0-7.2, P  less than  0.001). The number of adherent patients decreased only in patients on bi-therapy from 42 (79.2%) to 37 (69.8%, P  greater than 0.05).

Conclusions: Adding anti-HCV therapy to antiretroviral treatment significantly increases treatment complexity and the incidence of blips. The introduction of anti-HCV therapy is also associated with a decrease in the number of adherent patients. The regimen complexity calculation may be useful for identifying patients who need more care from health care professionals or are at risk for failure to comply with treatment regimens.