Hyperparameter Importance Across Datasets

With the advent of automated machine learning, automated hyperparameter optimization methods are by now routinely used in data mining. However, this progress is not yet matched by equal progress on automatic analyses that yield information beyond performance-optimizing hyperparameter settings. In this work, we aim to answer the following two questions: Given an algorithm, what are generally its most important hyperparameters, and what are typically good values for these? We present methodology and a framework to answer these questions based on meta-learning across many datasets. We apply this methodology using the experimental meta-data available on OpenML to determine the most important hyperparameters of support vector machines, random forests and Adaboost, and to infer priors for all their hyperparameters. The results, obtained fully automatically, provide a quantitative basis to focus efforts in both manual algorithm design and in automated hyperparameter optimization. The conducted experiments confirm that the hyperparameters selected by the proposed method are indeed the most important ones and that the obtained priors also lead to statistically significant improvements in hyperparameter optimization.Comment: \c{opyright} 2018. Copyright is held by the owner/author(s). Publication rights licensed to ACM. This is the author's version of the work. It is posted here for your personal use, not for redistribution. The definitive Version of Record was published in Proceedings of the 24th ACM SIGKDD International Conference on Knowledge Discovery & Data Minin

Quality of Life after Venous Stenting for Post-thrombotic Syndrome and the Effect of Inflow Disease

Objective: Patients with PTS experience an impaired quality of life (QoL). We aimed to study QoL in patients stented for post thrombotic syndrome (PTS) and analyze the influence of different parameters. Methods: Patients stented for PTS after iliofemoral deep vein thrombosis were asked to complete the Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) and the Short Form Health Survey (SF-36) in this cross-sectional study. All other data were collected retrospectively. Primary endpoints were median CIVIQ-20 and physical (PCS) and mental (MCS) component summary SF-36 scores. The influence of age, sex, and years between the procedure and completion of questionnaire were investigated using a multivariate linear regression model. Wilcoxon signed rank test compared the PCS and MCS with the normative. Effects of inflow from the deep femoral vein (DFV) and/or the femoral vein (FV) on QoL was analyzed in patients with patent stents. Results: The response rate was 70.3% (n = 45/64). Time period (median) from stenting to questionnaire completion was 6.6 years (IQR: 8.0). Most stents were placed unilateral left-sided (73.3%). For patients with patent stents (n = 42) median CIVIQ-20 was 35.5 (IQR: 17.3), higher than the minimum of 20.0 (P < .001). Median PCS of 44.7 (IQR: 14.2) was lower (P < .001), and MCS of 55.9 (IQR: 7.1) higher (P = .001) than the normative (50.0). Time since stenting and sex were not associated with QoL. Age was a significant predictor [standardized coefficient ss = .36, P = .04] for QoL using the CIVIQ-20, but not for the SF-36. Inflow disease did not impact QoL, but patients with occluded stents (n = 3) had poor functioning levels. Conclusion: Quality of life is impaired after venous stenting for PTS, particularly physical functioning, among patients with an open stent, but was similar between patients with good and impaired inflow. Patients with a permanent stent occlusion had the lowest QoL

Quality of Life after Venous Stenting for Post-thrombotic Syndrome and the Effect of Inflow Disease

Objective: Patients with PTS experience an impaired quality of life (QoL). We aimed to study QoL in patients stented for post thrombotic syndrome (PTS) and analyze the influence of different parameters. Methods: Patients stented for PTS after iliofemoral deep vein thrombosis were asked to complete the Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) and the Short Form Health Survey (SF-36) in this cross-sectional study. All other data were collected retrospectively. Primary endpoints were median CIVIQ-20 and physical (PCS) and mental (MCS) component summary SF-36 scores. The influence of age, sex, and years between the procedure and completion of questionnaire were investigated using a multivariate linear regression model. Wilcoxon signed rank test compared the PCS and MCS with the normative. Effects of inflow from the deep femoral vein (DFV) and/or the femoral vein (FV) on QoL was analyzed in patients with patent stents. Results: The response rate was 70.3% (n = 45/64). Time period (median) from stenting to questionnaire completion was 6.6 years (IQR: 8.0). Most stents were placed unilateral left-sided (73.3%). For patients with patent stents (n = 42) median CIVIQ-20 was 35.5 (IQR: 17.3), higher than the minimum of 20.0 (P &lt;.001). Median PCS of 44.7 (IQR: 14.2) was lower (P &lt;.001), and MCS of 55.9 (IQR: 7.1) higher (P =.001) than the normative (50.0). Time since stenting and sex were not associated with QoL. Age was a significant predictor [standardized coefficient ß =.36, P =.04] for QoL using the CIVIQ-20, but not for the SF-36. Inflow disease did not impact QoL, but patients with occluded stents (n = 3) had poor functioning levels. Conclusion: Quality of life is impaired after venous stenting for PTS, particularly physical functioning, among patients with an open stent, but was similar between patients with good and impaired inflow. Patients with a permanent stent occlusion had the lowest QoL.</p

Using CT colonography as a triage technique after a positive faecal occult blood test in colorectal cancer screening

Item does not contain fulltextOBJECTIVE: The purpose of this study was to evaluate the effectiveness of CT colonography (CTC) as a triage technique in faecal occult blood test (FOBT)-positive screening participants. METHODS: Consecutive guaiac (G-FOBT) and immunochemical (I-FOBT) FOBT-positive patients scheduled for colonoscopy underwent CTC with iodine tagging bowel preparation. Each CTC was read independently by two experienced observers. Per patient sensitivity, specificity and positive and negative predictive values (PPV and NPV) were calculated based on double reading with different CTC cut-off lesion sizes using segmental unblinded colonoscopy as the reference standard. The acceptability of the technique to patients was evaluated with questionnaires. RESULTS: 302 FOBT-positive patients were included (54 G-FOBT and 248 I-FOBT). 22 FOBT-positive patients (7%) had a colorectal carcinoma and 211 (70%) had a lesion >or=6 mm. Participants considered colonoscopy more burdensome than CTC (por=6 mm. The PPV of CTC was 87% (95% CI 80% to 93%) and NPV 77% (95% CI 69% to 85%). Using CTC as a triage technique in 100 FOBT-positive patients would mean that colonoscopy could be prevented in 28 patients while missing >or=10 mm lesions in 2 patients. CONCLUSION: CTC with limited bowel preparation has reasonable predictive values in an FOBT-positive population and a higher acceptability to patients than colonoscopy. However, due to the high prevalence of clinically relevant lesions in FOBT-positive patients, CTC is unlikely to be an efficient triage technique in a first round FOBT population screening programme

The efficacy of the modified Atkins diet in North Sea Progressive Myoclonus Epilepsy:an observational prospective open-label study

Background: North Sea Progressive Myoclonus Epilepsy is a rare and severe disorder caused by mutations in the GOSR2 gene. It is clinically characterized by progressive myoclonus, seizures, early-onset ataxia and areflexia. As in other progressive myoclonus epilepsies, the efficacy of antiepileptic drugs is disappointingly limited in North Sea Progressive Myoclonus Epilepsy. The ketogenic diet and the less restrictive modified Atkins diet have been proven to be effective in other drug-resistant epilepsy syndromes, including those with myoclonic seizures. Our aim was to evaluate the efficacy of the modified Atkins diet in patients with North Sea Progressive Myoclonus Epilepsy. Results: Four North Sea Progressive Myoclonus Epilepsy patients (aged 7-20 years) participated in an observational, prospective, open-label study on the efficacy of the modified Atkins diet. Several clinical parameters were assessed at baseline and again after participants had been on the diet for 3 months. The primary outcome measure was healthrelated quality of life, with seizure frequency and blinded rated myoclonus severity as secondary outcome measures. Ketosis was achieved within 2 weeks and all patients completed the 3 months on the modified Atkins diet. The diet was well tolerated by all four patients. Health-related quality of life improved considerably in one patient and showed sustained improvement during long-term follow-up, despite the progressive nature of the disorder. Health-related quality of life remained broadly unchanged in the other three patients and they did not continue the diet. Seizure frequency remained stable and blinded rating of their myoclonus showed improvement, albeit modest, in all patients. Conclusions: This observational, prospective study shows that some North Sea Progressive Myoclonus Epilepsy patients may benefit from the modified Atkins diet with sustained health-related quality of life improvement. Not all our patients continued on the diet, but nonetheless we show that the modified Atkins diet might be considered as a possible treatment in this devastating disorder

Chondrodysplasia, enchondromas and a chest deformity causing severe pulmonary morbidity in a boy with a PTHLH duplication:A case report

Parathyroid hormone-like hormone (PTHLH) plays an important role in bone formation. Several skeletal dysplasias have been described that are associated with disruption of PTHLH functioning. Here we report on a new patient with a 898 Kb duplication on chromosome 12p11.22 including the PTHLH gene. The boy has multiple skeletal abnormalities including chondrodysplasia, lesions radiographically resembling enchondromas and posterior rib deformities leading to a severe chest deformity. Severe pulmonary symptoms were thought to be caused by limited mobility and secondary sputum evacuation problems due to the chest deformity. Imaging studies during follow-up revealed progression of the number of skeletal lesions over time. This case extends the phenotypic spectrum associated with copy number variation of PTHLH