Feature impact assessment: a new score to identify relevant metabolomics features in artificial neural networks using validated labels.

INTRODUCTION: Artificial Neural Networks (ANN) are increasingly used in metabolomics but are hard to interpret. OBJECTIVES: We aimed at developing a feature impact score that is model-agnostic, simple, and interpretable. METHODS: Feature Impact Assessment (FIA) is calculated by varying combinations of features within their observed value range and checking for changes in prediction outcomes. FIA was implemented in R and tested on metabolomics datasets. RESULTS: FIA exceeded LIME and SHAP in selecting biologically meaningful features. Values were comparable across different ANN architectures. CONCLUSION: FIA is a novel score ranking feature impact, helping interpreting ANN in the metabolomics field.

Cost-effectiveness of short-protocol emergency brain MRI after negative non-contrast CT for minor stroke detection.

OBJECTIVES: To investigate the cost-effectiveness of supplemental short-protocol brain MRI after negative non-contrast CT for the detection of minor strokes in emergency patients with mild and unspecific neurological symptoms. METHODS: The economic evaluation was centered around a prospective single-center diagnostic accuracy study validating the use of short-protocol brain MRI in the emergency setting. A decision-analytic Markov model distinguished the strategies "no additional imaging" and "additional short-protocol MRI" for evaluation. Minor stroke was assumed to be missed in the initial evaluation in 40% of patients without short-protocol MRI. Specialized post-stroke care with immediate secondary prophylaxis was assumed for patients with detected minor stroke. Utilities and quality-of-life measures were estimated as quality-adjusted life years (QALYs). Input parameters were obtained from the literature. The Markov model simulated a follow-up period of up to 30 years. Willingness to pay was set to $100,000 per QALY. Cost-effectiveness was calculated and deterministic and probabilistic sensitivity analysis was performed. RESULTS: Additional short-protocol MRI was the dominant strategy with overall costs of $26,304 (CT only: $27,109). Cumulative calculated effectiveness in the CT-only group was 14.25 QALYs (short-protocol MRI group: 14.31 QALYs). In the deterministic sensitivity analysis, additional short-protocol MRI remained the dominant strategy in all investigated ranges. Probabilistic sensitivity analysis results from the base case analysis were confirmed, and additional short-protocol MRI resulted in lower costs and higher effectiveness. CONCLUSION: Additional short-protocol MRI in emergency patients with mild and unspecific neurological symptoms enables timely secondary prophylaxis through detection of minor strokes, resulting in lower costs and higher cumulative QALYs. KEY POINTS: • Short-protocol brain MRI after negative head CT in selected emergency patients with mild and unspecific neurological symptoms allows for timely detection of minor strokes. • This strategy supports clinical decision-making with regard to immediate initiation of secondary prophylactic treatment, potentially preventing subsequent major strokes with associated high costs and reduced QALY. • According to the Markov model, additional short-protocol MRI remained the dominant strategy over wide variations of input parameters, even when assuming disproportionally high costs of the supplemental MRI scan.

Burn first aid knowledge in Germany and the influences of social-economic factors.

BACKGROUND: Optimal management of burns always starts with the first aid. Results of numerous studies carried out in different countries indicated in general a low awareness of first aid of burns irrespective of whether the income of the country was high, middle or low. The aim of the study was to investigate the knowledge in burn first aid in Germany and compare it to an Australian study from 2013. METHODS: From January 2016 until August 2017 patients, visitors and medical personnel in the emergency room of two large hospitals in Southern and the Western part of Germany were asked to take part in a paper based multiple-choice survey. RESULTS: Altogether 1229 people took part in the questionnaire, 588 from Bavaria and 641 from North Rhine-Westphalia; 45,2% males and 54.8% females. Their age ranged from 19 to 52 with a mean of 37.2 years. Hereby participants that had taken part in first aid training and people working in health care had significant more correct answers. Overall, only approximately a third of the given answers were correct. CONCLUSION: Our study suggests that there is room for improvement since only a minority of the German population is familiar with first aid principles dealing with burns. Although more than 40% had taken part in a first aid training, the questioned people gave less correct answers than the Australians in 2013.