Incidence and risk of osteonecrosis of the jaw among the Taiwan osteoporosis population

Abstract

Evidence of the incidence and risk of osteonecrosis of the jaw (ONJ) in Asian osteoporosis populations receiving different osteoporosis medications is lacking. We found that there is no excess incidence of or risk for ONJ in osteoporosis patients >50 years old using alendronate as compared with patients using raloxifene or calcitonin under real-world conditions in Taiwan. To provide information on ONJ in Asian populations, this study compares the incidence and risk of ONJ between patients receiving alendronate and those receiving non-bisphosphonate osteoporosis medications in Taiwan. Enrollees in the National Health Insurance Research Database (NHIRD) from 2003 to 2007, aged above 50 years, with vertebral/hip fracture, and new to osteoporosis therapy were recruited. Patients with Paget's disease or cancer during the baseline period were excluded. Patients were classified into either the alendronate or the calcitonin/raloxifene (control) group according to their exposure during follow-up. Previously proposed possible ONJ diagnosis codes were adopted as potential ONJ cases, but qualifying cases also had a repeated ONJ diagnosis within 8 weeks of the first diagnosis and received one or more broad-spectrum oral antibiotics. Cox modeling compared the risk of ONJ between the alendronate and the control groups, which were matched using propensity scores. Results were examined in series sensitivity analyses, including different cumulative dose groups. We found 25 potential ONJ cases in the alendronate (N = 18,030) and 21 in the control groups (N = 25,615). Over the 6-year follow-up period, no increased risk of ONJ in the alendronate group in the original (hazard ratio (HR), 0.87; 95% confidence interval (CI), 0.47-1.58) or propensity score-matched cohorts (HR, 0.86; 95% CI, 0.44-1.69) was found. All comparison groups exhibited a similar incidence of ONJ, ranging from 6.9 to 8.2/10,000 person-years. Under real-world conditions, there is no excess risk for ONJ in osteoporosis patients >50 years old using alendronate as compared with patients using raloxifene or calcitonin.