Conclusion

In this prospective observational cohort of patients with newly diagnosed pSjD, low medication adherence was frequent during follow-up. Adherence was not clearly associated with systemic disease activity, Sjögren-specific symptom burden, psychological status, fatigue, functional status, or health-related quality of life. In contrast, a lower necessity-concern differential was observed among patients with low adherence and was associated with adherence status in exploratory logistic regression. Because medication adherence and beliefs about medicines were assessed at the same time point, and because the regression model was based on a relatively small sample, these findings should be interpreted as exploratory and non-causal. These findings highlight the potential importance of perceptual factors in adherence behavior. Future studies involving larger, multicenter cohorts, objective adherence measures, and longitudinal designs are needed to better clarify these relationships and to inform the development of targeted adherence-support strategies.