Risk factors and reasons for romosozumab nonadherence in a case-control study.

Risk factors and reasons for romosozumab nonadherence remain unclear. This study compared patients who adhered to romosozumab therapy with those who did not to identify possible risk factors and reasons for treatment nonadherence. This case-control study included all eligible patients diagnosed with osteoporosis who received romosozumab therapy at our hospital between February 2022 and March 2024. The patients were divided into adherence and nonadherent groups. Nonadherence was defined as failure to follow the monthly injection schedule for 12 injections over a one-year period, without transitioning to other antiosteoporotic medications. Relevant data were retrospectively collected from the patients' medical records. Univariate and logistic regression analyses were performed to identify the associations of patient characteristics with romosozumab nonadherence. A subgroup analysis was performed to identify the associations between the reasons for nonadherence and the type of payment for romosozumab therapy. The adherence and nonadherent groups comprised 62 and 69 patients, respectively. Male patients had a 9.03-fold higher risk of nonadherence than did female patients (P = .041). Self-payment for medications was associated with a 2.756-fold higher risk of nonadherence than was receiving a full subsidy (P = .024). The most common reasons for nonadherence were patient-related factors (87.0%, 60 of the 69 patients in the nonadherent group), followed by medicine-related factors (8.7%, 6 patients) and health system-related factors (4.3%, 3 patients). Male sex and self-payment for medications are risk factors for romosozumab nonadherence. Patient-related factors appear to be the most common reasons for nonadherence. These results can aid healthcare providers in implementing appropriate interventions.