The Epidemiology of Hip Fracture among Subjects with Pyogenic Liver Abscess (PLA): A Nationwide Population-Based Study

Pyogenic liver abscess (PLA) is a potentially fatal disease that can stimulate prominent systemic inflammation. Osteoporotic hip fracture is a major complication of systemic inflammation. This study tried to determine the epidemiology of hip fractures among PLA patients. All subjects admitted due to PLA during 1999∼2010 were assessed, excluding the subjects with a history of high energy trauma, malignancy, and previous hip fracture. We matched the control subjects to PLA patients according to age, gender, and the coding of osteoporosis by 1 : 4 ratio. The PLA patients had a 1.17-fold risk of hip fracture than the controls (aHR = 1.17, 95% CI = 1.07–1.29) after adjusting for gender, age, and comorbidities. Considering death as the competing event of suicide, the PLA patients had 1.10-fold suicide risk (aHR = 1.10, 95% CI: 1.00–1.21) than the control subjects under the competing risks regression model. The cumulative incidence of hip fracture was higher in the PLA cohort (log-rank test, p < 0.001). When compared to the controls, the fracture risk was 18.4-fold (aHR = 18.4, 95% CI = 13.0–26.1) for the PLA patients admitted 2-3 times per year and 46.0-fold (aHR = 46.0, 95% CI = 31.2–67.8) for the PLA patients admitted ≧4 times per year. The impact of PLA is more prominent among the subjects aged <45 years (aHR = 2.81, 95% CI = 1.42–5.56). Preventive measures for hip fracture might be warranted for PLA patients.