Age and clinical outcomes after hip fracture surgery: do octogenarian, nonagenarian and centenarian classifications matter?

Abstract Background older patients with hip fractures are arbitrarily classified as octogenarians, nonagenarians and centenarians. We have designed this study to quantify in-hospital mortality and complications among each of these groups. We hypothesised that the associations between age and in-hospital mortality and complications are continuously increasing, and that these risks increase rapidly when patients reach a certain age. Methods this research is a retrospective cohort study using nationwide database between 2010 and 2018. Patients undergoing hip fracture surgery, and aged 60 or older, were included. The associations between patient age, in-hospital mortality and complications were visualised using the restricted cubic spline models, and were analysed employing multivariable regression models. Then, octogenarians, nonagenarians and centenarians were compared. Results among a total of 565,950 patients, 48.7% (n = 275,775) were octogenarians, 23.0% (n = 129,937) were nonagenarians and 0.7% (n = 4,093) were centenarians. The models presented three types of association between age, in-hospital mortality and complications: (i) a continuous increase (mortality and respiratory complications); (ii) a mild increase followed by a steep rise (intensive care unit admission, heart failure, renal failure and surgical site hematoma) and (iii) a steep increase followed by a limited change (coronary heart disease, stroke and pulmonary embolisms). Conclusion we identified three types of association between age and clinical outcomes. Patients aged 85–90 may constitute the upper threshold for age categorisations, because the risk of in-hospital complications changed dramatically at that stage. This information can improve clinical awareness of various complications and support collective decision-making.