Background: Osteoporotic hip fractures are associated with high mortality and morbidity in people of advanced age; however, few studies have investigated the complication rates in nonagenarians. In this study, we applied a competing risk analysis to estimate the mortality, readmission, and reoperation rates after surgery for hip fracture among nonagenarians.
Methods: A total of 11,184 nonagenarians (aged ≥ 90) who received surgery for hip fracture during the period 1 January 1997 and 31 December 2010 were selected from Taiwan's National Health Insurance (NHI) database. Nonagenarians were followed up until the end of 2012, death, or the date they left the NHI program. Cumulative mortality was estimated using the Kaplan-Meier analysis and risk factors for mortality were investigated using a Cox proportional hazards model. Competing risk analysis was used to estimate cumulative incidence rates and to assess the risk factors for reoperation and readmission.
Results: The mortality rates were 29.5% at 1 year, 45.0% at 2 years and 78.1% at 5 years. The cumulative incidence rates of reoperation were 7.3% at 1 year, 9.2% at 2 years and 11.6% at 5 years whereas those of readmission were 18.9% at 1 month and 24.1% at 3 months. Significant risk factors for death included age, male gender, trochanteric fracture, and higher Charlson comorbidity index (CCI) whereas those for reoperation were age, cervical fracture and higher CCI. Furthermore, age, male gender, and higher CCI were risk factors for readmission.
Conclusions: The overall 2-years mortality rate among nonagenarians in Taiwan was around 45%, the 2-years reoperation rate was around 9% and the 90-days medical complication rate was around 24%. High complication rates are associated with increased risk for death. Postoperative care to prevent medical complications is likely the most effective strategy to reduce mortality rates among nonagenarians with hip fracture.
Keywords: Complication; Hip fracture surgery; Mortality; Nonagenarians; Readmission; Reoperation.