Medication adherence and associated factors in patients with chronic hepatitis B in Zhejiang Province, Eastern China

Chronic hepatitis B (CHB) remains a significant public health burden in China. Sustained adherence to long-term nucleos(t)ide analogues (NAs) therapy is crucial for preventing disease progression, but large-scale evidence on adherence and its influencing factors remains limited, particularly in the context of evolving healthcare policies. A cross-sectional study was conducted from June to August 2025 in Zhejiang Province, using phased stratified sampling. Data were collected through structured, interviewer-administered questionnaires, including the validated 8-item Morisky Medication Adherence Scale (MMAS-8). Mann-Whitney U and Kruskal-Wallis tests were used to compare ordinal variables across categories of categorical variables. A partial proportional odds model with city as a fixed effect was used to identify factors associated with adherence. Sensitivity analyses using linear mixed models with MMAS-8 scores as a continuous outcome were performed. Among the 907 CHB patients, the median MMAS-8 score was 7.75 (IQR: 6.75-8), with 46.0% classified as high adherence, 34.5% as medium adherence, and 19.5% as low adherence. In the adjusted partial proportional odds model, older age (50–59 years: OR = 1.73, 95% CI: 1.12–2.67; ≥60 years: OR = 1.81, 95% CI: 1.14–2.89), having a fixed dosing time (OR = 4.01, 95% CI: 2.13–7.55), and attending regular follow-up (OR = 1.98, 95% CI: 1.35–2.92) were associated with higher adherence. Conversely, taking two or more additional daily prescription medications (OR = 0.61, 95% CI: 0.37–0.99) and an annual NAs cost of 300–599 RMB (OR = 0.59, 95% CI: 0.42–0.83) were associated with lower adherence. Notably, no patient cited unaffordable medication costs as a reason for missed doses. Forgetfulness (58.7%) and perceived symptomatic improvement (21.8%) were the most frequently reported barriers. Adherence to NAs therapy among CHB patients in Zhejiang was generally favorable, with most patients classified as having medium or high adherence. Adherence was positively associated with age, fixed dosing time, and regular clinical follow-up, and negatively associated with polypharmacy and specific out-of-pocket costs. Interventions should focus on younger patients, simplify medication regimens, provide behavioral support, and reinforce patient education on the necessity of lifelong therapy.