Longitudinal Adherence Trajectories of First-Line Nucleotide Analogues among US Older Adults with Chronic Hepatitis B.

BACKGROUND

The effectiveness of first-line nucleot(s)side analogs (NAs) for managing chronic hepatitis B (CHB) depends heavily on treatment adherence; however, evidence on longitudinal adherence patterns is limited, especially in older adults.

OBJECTIVE

This study examined longitudinal adherence trajectories of NAs among older adults with CHB.

METHODS

This retrospective cohort study involved continuously enrolled Medicare beneficiaries aged ≥ 65 years with CHB from 2014-2019. Monthly adherence was evaluated using proportion of days covered for incident NAs users, specifically entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF). Longitudinal adherence patterns were analyzed using group-based trajectory modeling (GBTM) over a 12-month follow-up. The variation in adherence trajectories across first-line NAs was examined using a multinomial logistic regression model, adjusted for baseline covariates.

RESULTS

The study cohort comprised 3,317 older adults with CHB, with a mean age of 72.6 years, and 57.85% were men. The GBTM identified three long-term adherence patterns: consistently adherent (56.89%), gradual decline (24.78%), and rapid decline (18.33%). The consistently adherent patients varied across the individual NAs (ETV = 52.21%, TDF = 57.39%, and TAF = 71.06%). Multinomial logistic model found that patients on TAF had 0.41 times lower odds of being rapid decliners (95% confidence interval [CI]: 0.34-0.49) and 0.45 times lower odds of being gradual decliners (95%CI: 0.39-0.53), compared to ETV.

CONCLUSIONS

Over half of older adults with CHB consistently adhered to NAs, with significant variation in adherence patterns across the individual NAs. Overall, TAF was less likely to be associated with declining adherence patterns than other NAs. Understanding these long-term adherence patterns can help in developing targeted interventions to improve CHB care in older adults.