Influence of patient perceptions and preferences for osteoporosis medication on adherence behavior in the Denosumab Adherence Preference Satisfaction study

Objective: This study aims to evaluate patient perceptions of subcutaneous denosumab or oral alendronate in postmenopausal women with or at risk for osteoporosis and how these perceptions influence adherence. Methods: Postmenopausal women with low bone mass were randomized to denosumab 60 mg every 6 months for 1 year (treatment period 1 [TP1]) followed by alendronate 70 mg once weekly for 1 year (treatment period 2 [TP2]), or vice versa. Beliefs about Medicines Questionnaire data were collected at baseline and at 6, 12, 18, and 24 months; a necessity-concerns differential (NCD) was calculated for each time point. Logistic regression analyses were performed to evaluate the influences of baseline characteristics on nonadherence. Results: Participants included 250 women (alendronate/denosumab, n = 124; denosumab/alendronate, n = 126). During TP1, the NCD at month 6 was higher with denosumab than with alendronate (P = 0.0076). In TP2, the NCD was higher for women switched to denosumab than for women switched to alendronate at 6 months (P = 0.0126) and 12 months (P = 0.4605). Denosumab was preferred to alendronate regardless of treatment sequence (P < 0.0001). Covariate analysis revealed that higher TP2 baseline necessity scores were associated with lower odds of nonadherence (P = 0.0055), whereas higher concerns about medication scores were associated with higher odds of nonadherence (P = 0.0247). Higher NCD scores were also associated with lower odds of nonadherence (P = 0.0015). Conclusions: Participants preferred denosumab to alendronate while on treatment and had more positive perceptions of denosumab than alendronate. These perceptions were associated with better adherence.