Delayed Denosumab Injections and Bone Mineral Density Response: An Electronic Health Record-based Study

CONTEXT: Discontinuation of denosumab leads to a rapid reversal of its therapeutic effect. However, there are no data regarding how unintended delays or missed injections of denosumab impact bone mineral density (BMD) response. OBJECTIVE: We examined the association of delays in injections of denosumab with BMD change. DESIGN: We used electronic medical records from two academic hospitals from 2010 to 2017. PARTICIPANTS: Patients older than 45 years of age and used at least 2 doses of 60 mg denosumab. Denosumab adherence was evaluated by the medication coverage ratio (MCR). Good adherence corresponds to a dosing interval /=93%), moderate adherence corresponds to an interval of 7 to 10 months (MCR 75%-93%), and poor adherence corresponds to an interval >/=10 months (MCR