Each of these potential risk factors was separately entered into a regression model. Additionally, alcohol consumption was considered (depending
on the proportion of subjects with data selleck chemicals for this variable). Baseline demographic characteristics for cases and controls were compared. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each risk factor in a univariate analysis using conditional logistic regression, comparing cases and controls. After SRT1720 excluding risk factors that had an insignificant OR or did not reach an overall 1% prevalence, a final, multivariable logistic regression model was derived. Results Ion Channel Ligand Library mouse A total of 792 cases and 4,660 controls were included in the analysis, with 99% of cases having at least five matched controls. Fifty-three percent of the cases and 53.1% of the controls were female, with a mean age of 57.5 years
among cases and 57.6 years among controls. Mean observation time was 8.9 person-years for cases and 9.4 person-years for controls. The most common site of ON was the hip, representing 75.9% of the cases (Table 2). Table 2 Baseline characteristics of cases and controls Cases (N = 792) Controls (N = 4,660) Overall (N = 5,452) Sex Female 420 (53.0%) 2,473 (53.1%) 2,893 (53.1%) Male 372 (47.0%) 2,187 (46.9%) 2,559 (46.9%) Age (years) Mean
(SD) 57.5 Fossariinae (18.99) 57.6 (18.90) 57.6 (18.91) Median (IQR) 58.5 (42.0–73.0) 59.0 (42.0–73.0) 59.0 (42.0–73.0) Person-years of observation Mean (SD) 8.9 (4.1) 9.4 (4.0) 9.4 (4.0) Median (IQR) 9.3 (5.9–11.8) 9.7 (6.3–12.5) 9.7 (6.2–12.5) Site of osteonecrosis Hip 601 (75.9%) 0 (0.0%) 601 (11.0%) Wrist 36 (4.5%) 0 (0.0%) 36 (0.7%) Knee 20 (2.5%) 0 (0.0%) 20 (0.4%) Shoulder 18 (2.3%) 0 (0.0%) 18 (0.3%) Foot 15 (1.9%) 0 (0.0%) 15 (0.3%) Ankle 13 (1.7%) 0 (0.0%) 13 (0.2%) Jaw 3 (0.4%) 0 (0.0%) 3 (0.1%) Othera 20 (2.5%) 0 (0.0%) 20 (0.4%) NOS 66 (8.3%) 0 (0.0%) 66 (1.2%) aOther sites (≤5 cases each) included head of humerus, medial femoral condyle, talus, femoral condylar, larynx, pelvis, rib, temp bone, and tibia SD standard deviation; IQR interquartile range; NOS not otherwise specified The age-adjusted annual incidence rates of ON by sex and the osteonecrosis incidence rates by sex and age cohort are shown in Figs. 1 and 2. Overall, the recorded incidence of ON increased over time from approximately 1.4/100,000 in 1989 to approximately 3/100,000 in 2003.