ZD1839 datasheet Statistically significant risk factors for ON from the final multivariable logistic regression model were systemic corticosteroid

use (intermittent and exposed), hospitalization, referral see more or specialist visit, bone fracture, any cancer, osteoporosis, connective tissue disease, and osteoarthritis (Table 4). An additional analysis was performed in the subset of cases with hip ON and their matched controls because these represented a potentially more homogeneous population and also included the majority (75.9%) of the identified ON cases overall (Table 2). A total of 601 cases and 3,533 controls were included in the hip ON subset analysis. Approximately 54% of cases and controls in the hip ON subset were female with a mean age of 58.3 years. Statistically significant risk factors for hip ON from the adjusted multivariable logistic regression model were the same as the overall ON population except for the inclusion of immunosuppressant use (intermittent) and the exclusion of osteoporosis (Table 5). Of recent interest Selleck MX69 is the use of bisphosphonates and a postulated association with osteonecrosis of the jaw (ONJ) [16–19]. In our case–control study, only 4.4% of ON cases were bisphosphonate users within the previous 2 years (Table 3). Across all cases, only three had the jaw

mentioned as the site of ON, and none of them had been exposed to bisphosphonates (Table 2). Table 6 reports the type of bisphosphonate exposure for cases and controls in this study. Etidronate was the most common compound reported; this was the only oral bisphosphonate marketed for the treatment of osteoporosis in the UK in the early 1990s. Further, the distribution by type of bisphosphonate is overall consistent with market share in the UK

during the study period. No cases or controls with intravenous bisphosphonate use were identified in this study. Exposure to bisphosphonates was not associated with an increased risk Decitabine nmr of ON in the adjusted model of all skeletal sites combined (Table 4) or in the adjusted model for the hip subset (Table 5). Table 6 Types of bisphosphonates used by cases and controls within the previous 2-year study period Type of bisphosphonate Cases (N = 792) Controls (N = 4660) Overall (N = 5452) Alendronate only 9 (26%) 9 (17%) 18 (20%) Clodronate only 1 (3%) 0 (0%) 1 (1%) Etidronate only 20 (57%) 42 (79%) 62 (70%) Risedronate only 2 (6%) 1 (2%) 3 (3%) Alendronate and risedronate 1 (3%) 0 (0%) 1 (1%) Alendronate and etidronate 1 (3%) 1 (2%) 2 (2%) Alendronate, etidronate, and risedronate 1 (3%) 0 (0%) 1 (1%) Total number of cases/controls 35 53 88 Discussion From 1989 to 2003, in this study population, the observed incidence of ON ranged from approximately 1.4–3.0/100,000 within the combined GPRD/THIN dataset. The reason for the increased incidence over time is not known but could be due in part to the increasing use of more advanced radiographic techniques, especially MRI, that are more sensitive in detecting ON.