Medication nonadherence during the first 24 weeks of treatment for chronic hepatitis C was often deliberate and attributed to feeling well, as opposed to forgetfulness or other factors, in a recent study.
Researchers evaluated adherence to treatment in a cohort of 401 patients with chronic HCV genotype 1. All participants had been enrolled in the Virahep-C study and received therapy with pegylated interferon (PEG) and ribavirin (RBV) for 24 weeks, with responders receiving an additional 24 weeks (n=242). Adherence was measured using the Medication Event Monitoring System, which recorded when the medication container was opened via a computer chip in the cap.
Excluding the final month, patients missed fewer than 10% of PEG doses each week. The number of missed RBV doses increased from approximately 15% in the first 24 weeks to 27% in the last 24 weeks. “Feeling good” was the most common reason provided for missed doses during study’s first half (28% of participants), while forgetting to take the medication was most common in the second half (21%).
Multivariate analysis indicated significant associations between missing PEG doses during the first 24 weeks and African-American race (OR=2.22; 95% CI, 1.51-3.27 vs. Caucasian participants), unemployed status (OR=2.57; 95% CI, 1.68-3.92) and marital status (OR=1.46; 95% CI, 0.89-2.42 for never-married and OR=2.00; 95% CI, 1.23-3.28 for divorced, widowed or separated patients vs. those married or in relationships). Advanced age decreased the likelihood of missed doses (OR=0.76; 95% CI, 0.66-0.88 every 5 years). Only African-American race (OR=2.01; 95% CI, 1.48-2.73) and age (OR=0.8; 95% CI, 0.72-0.88 every 5 years) were associated with missing RBV doses during the first 24 weeks.
“These data demonstrate that patients miss medications during the first 24 weeks primarily because they ‘feel good,’ ” the researchers wrote. “This seems to reflect a deliberate decision on behalf of patients to consciously refrain from taking their medications when they feel good, and may be surprising to clinicians who assume that missed doses occur most often due to forgetfulness.”
Disclosure: See the study for a full list of relevant disclosures.