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

Summary 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.