Comparison of the Charlson Comorbidity Index with the ASA score for predicting 12-month mortality in acute hip fracture.

BACKGROUNDS: The ASA (American Society of Anaesthesiologists) Score is the current standard for measuring comorbidity in the Australian Hip Fracture registry, however it has never been validated for this purpose. Subsequently, a more appropriate and useful measure should be investigated. This study aimed to compare the ASA and Charlson Comorbidity Index (CCI) scores in predicting 12-month mortality following acute hip fracture. METHODS: A retrospective analysis was performed on an audit database of patients who were admitted to an orthogeriatric unit in a public metropolitan hospital from November 2010 to October 2011. 12-month mortality data was linked through a dual search of Queensland Health and mortality registry data. The Charlson comorbidity index was retrospectively applied. Demographics (age, gender, admission residence) and covariates including ASA, CCI, fracture type, fixation type, cognitive impairment on admission, BMI and time to surgery were analysed with logistic regression. ROC curve analysis was performed to assess varying thresholds for each comorbidity system. RESULTS: A total of 320 patients were available for audit. Unadjusted bivariate analysis demonstrated significant difference between groups regarding increased age (p = 0.004), ASA score (p<0.001), CCI (p = 0.002), age-adjusted CCI (p = 0.002) and admission from a care facility (p<0.001). Logistic regression analysis demonstrated that only ASA (p<0.001) and admission from a care facility (p<0.001, OR=3.36, 95% CI = 1.9 - 6.0) independently predicted 12-month mortality; CCI was not a significant predictor in any models (p = 0.827, age-adjusted CCI: p = 0.864). Using ROC analysis, the ASA (AUC=0.668) outperformed either CCI (AUC=0.607 (CCI), AUC=0.614 (CCI age-adjusted). CONCLUSIONS: The ASA score is independently associated with 12-month mortality; this was not replicated using either version of the CCI. The data does not suggest using the CCI in registry level datasets for the purposes of predicting 12-month mortality.

Anaesthetic EEG signal denoise using improved nonlocal mean methods.

This paper applies the nonlocal mean (NLM) method to denoise the simulated and real electroencephalograph signals. As a patch-based method, the NLM method calculates the weighted sum of a patch. The weight of each point is determined by the similarity between the points of the own patch and its neighbor. Based on the weighted sum, the noise is filtered out. In this study, the NLM denoising method is applied to signals with additive Gaussian white noise, spiking noise and specific frequency noise and the results are compared with that of the popular sym8 and db16 Wavelet threshold denoising (WTD) methods. The outcomes show that the NLM on average achieves 2.70 dB increase in improved signal to noise ratio (SNRimp) and 0.37 % drop in improved percentage distortion ratio compared with WTD. The moving adaptive shape patches-NLM performs better than the original NLM when the signals change dramatically. In addition, the performance of combined NLMWTD denoising method is also better than original WTD method (0.50-4.89 dB higher in SNRimp), especially, when the signal quality is poor.

Dedicated hip fracture service: implementing a novel model of care.

BACKGROUND: Hip fracture is a common clinical problem with historically high morbidity and mortality, and various model of acute and subacute care have been employed. We describe 12-month results from the first dedicated hip fracture unit in Australia, and compare it with other models of care both locally and internationally. METHODS: This was performed as a prospective uncontrolled study over a 12-month period. After application of exclusion criteria, a total of 346 patients were yielded. Outcomes measured included performance indicators as well as morbidity and mortality data. RESULTS: Improvements in performance indicators (adequate preoperative medical assessment, time to surgery, return to premorbid residence, etc.) and morbidity and mortality data (such as pressure sores, infections and in-hospital death) are noted. CONCLUSIONS: Early results suggest more comprehensive preoperative assessment, shorter times to theatre, reduced post-operative complications and diminished mortality rates when the principles undermining this unit are instituted.