Prediction of second neurological attack in patients with clinically isolated syndrome using support vector machines

The aim of this study is to predict the conversion from clinically isolated syndrome to clinically definite multiple sclerosis using support vector machines. The two groups of converters and non-converters are classified using features that were calculated from baseline data of 73 patients. The data consists of standard magnetic resonance images, binary lesion masks, and clinical and demographic information. 15 features were calculated and all combinations of them were iteratively tested for their predictive capacity using polynomial kernels and radial basis functions with leave-one-out cross-validation. The accuracy of this prediction is up to 86.4% with a sensitivity and specificity in the same range indicating that this is a feasible approach for the prediction of a second clinical attack in patients with clinically isolated syndromes, and that the chosen features are appropriate. The two features gender and location of onset lesions have been used in all feature combinations leading to a high accuracy suggesting that they are highly predictive. However, it is necessary to add supporting features to maximise the accuracy. © 2013 IEEE

Low discriminating power of the modified Ottawa VTE risk score in a cohort of patients with cancer from the RIETE registry.

Treatment of patients with cancer-associated venous thromboembolism (VTE) remains a major challenge. The modified Ottawa score is a clinical prediction rule evaluating the risk of VTE recurrences during the first six months of anticoagulant treatment in patients with cancer-related VTE. We aimed to validate the Ottawa score using data from the RIETE registry. A total of 11,123 cancer patients with VTE were included in the analysis. According to modified Ottawa score, 2,343 (21 %) were categorised at low risk for VTE recurrences, 4,525 (41 %) at intermediate risk, and 4,255 (38 %) at high risk. Overall, 477 episodes of VTE recurrences were recorded during the course of anticoagulant therapy, with an incidence rate for low, intermediate, and high risk groups of 6.88 % (95 % CI 5.31-8.77), 11.8 % (95 % CI 10.1-13.6), and 21.3 % (95 % CI 18.8-24.1) patient-years, respectively. Overall mortality had an incidence rate of 21.1 % (95 % CI 18.2-24.3), 79.4 % (95 % CI: 74.9-84.1), and 134.7 % (95 % CI: 128.3-141.4) patient-years, respectively. The accuracy and discriminating power of the modified Ottawa score for VTE recurrence was modest, with low sensitivity, specificity and positive predictive value, and a C-statistics of 0.58 (95 % CI: 0.56-0.61). In our analysis, the modified Ottawa score did not accurately predict VTE recurrence among patients with cancer-associated thrombosis, thus hindering its use in clinical practice. It is time to define a new score including other clinical predictors