How the COVID-19 pandemic affected bone health: a retrospective, longitudinal study on denosumab persistence from the epicentre of European spreading.

Unlabelled: In this study, we investigated how the COVID-19 pandemic involved osteoporosis care in patients treated with denosumab. Almost a third of patients missed the prescription renewal, mandatory to obtain the subsidized drug. Among patients who suspended denosumab, more than half reported fragility fractures.

Purpose: This study aimed to evaluate persistence on denosumab (Dmab) treatment during the COVID-19 pandemic and the clinical effects of possible discontinuation.

Methods: We retrospectively assessed patients affected by osteoporosis and treated with Dmab, scheduled to have the yearly renewal of prescription between March 9, 2020, and May 9, 2021, 2 months after the second pandemic wave. In June 2022, a telephone survey started, by calling all patients who missed the yearly renewal of Dmab. Predictors of missed renewal and fragility fracture occurrence were assessed by logistic analyses.

Results: Patients scheduled to have a renewal of Dmab prescription during the observational period were 538 (age 75.5 ± 9.3 years, female 511). A total of 152 (28.2%) patients did not have the renewal. Patients not renewing Dmab prescription were significantly older (p = 0.01) and more frequently affected by pulmonary (p = 0.04) and cardiovascular comorbidity (p = 0.01). Telephone survey on non-persistent patients showed that 44 had died, 28 patients were missing, 23 shifted to bisphosphonate treatment, and 22 patients suspended Dmab. Following discontinuation, 12/22 patients (54.5%) reported fragility fractures; 5/22 had multiple fractures, for a total number of 18 fractures, mainly vertebral. Logistic analyses showed that the odds of Dmab withdrawal increased in older patients with pulmonary comorbidity and treated for a shorter time. Dmab discontinuation was the only variable that increased the risk of fracture.

Conclusion: This study provided real-world data about an impaired persistence of Dmab treatment resulting in an increased number of fragility fractures in a geographic area heavily affected by the outbreak of COVID-19.