Medication adherence is associated with the necessity-concern differential in newly diagnosed primary Sjögren disease: a prospective observational cohort study.

Abstract

The objectives of this study were, firstly, to assess medication adherence and, secondly, to evaluate the relationships between medication adherence and symptoms, disease activity, and patient-reported outcomes in patients with newly diagnosed primary Sjögren disease (pSjD). In this prospective observational cohort study, 54 patients with newly diagnosed pSjD were enrolled in a tertiary rheumatology clinic. Forty patients (74.1%) were reassessed after a mean follow-up of 21.36 ± 4.79 months. Medication adherence was evaluated using the Compliance Questionnaire for Rheumatology-5 (CQR-5), classifying patients as low or high adherence. Disease activity, symptom burden, psychological symptoms, fatigue, functional status, health-related quality of life, and medication beliefs were evaluated using ESSDAI, ESSPRI, HADS, fatigue severity assessment, HAQ, SF-12, and the Beliefs about Medicines Questionnaire (BMQ). The necessity-concern differential (NCD) was calculated as the BMQ-specific necessity score minus the concern score. Logistic regression analysis was exploratory. The cohort was predominantly female (52/54, 96.3%), with a mean age of 49.7 ± 9.5 years. At follow-up, 16 patients (40%) were classified as low adherence and 24 (60%) as high adherence. Baseline clinical and sociodemographic characteristics were comparable between groups. ESSDAI scores remained low and stable over time, and ESSPRI increased modestly in both groups without significant between-group differences. Psychological status, fatigue, functional status, and quality of life were similar across adherence categories. Specific necessity scores were numerically higher in high-adherence patients (3.37 ± 0.79 vs. 3.04 ± 1.06; p = 0.267), whereas concern scores tended to be higher in low-adherence patients (3.46 ± 0.92 vs. 3.07 ± 0.63; p = 0.115). The NCD was significantly lower in the low-adherence group than in the high-adherence group (- 0.43 ± 1.16 vs. 0.30 ± 0.96; p = 0.038). In exploratory logistic regression, higher NCD was associated with high adherence (OR 1.95, 95% CI 1.01-3.76). In patients with newly diagnosed pSjD, low medication adherence was frequent and was associated with patients' necessity-concern balance rather than clinical disease activity or patient-reported burden. Because adherence and medication beliefs were assessed at the same time point and CQR-5 has not been specifically validated in pSjD, these findings should be interpreted as exploratory and non-causal.