ABSTRACT
The systematic assessment of cognitive performance of older people without cognitive complaints is controversial and unfeasible. Identifying individuals at higher risk of cognitive impairment could optimize resource allocation. We aimed to develop and test machine learning models to predict cognitive impairment using variables obtainable in primary care settings. In this cross-sectional study, we included 8,291 participants of the baseline assessment of the ELSA-Brasil study, who were aged between 50 and 74 years and were free of dementia. Cognitive performance was assessed with a neuropsychological battery and cognitive impairment was defined as global cognitive z-score below 2 standard deviations. Variables used as input to the prediction models included demographics, social determinants, clinical conditions, family history, lifestyle, and laboratory tests. We developed machine learning models using logistic regression, neural networks, and gradient boosted trees. Participants' mean age was 58.3±6.2 years, 55% were female. Cognitive impairment was present in 328 individuals (4%). Machine learning algorithms presented fair to good discrimination (areas under the ROC curve between 0.801 and 0.873). Extreme Gradient Boosting presented the highest discrimination, high specificity (97%), and negative predictive value (97%). Seventy-six percent of the individuals with cognitive impairment were included among the highest ranked individuals by this algorithm. In conclusion, we developed and tested a machine learning model to predict cognitive impairment based on primary care data that presented good discrimination and high specificity. These characteristics could support the detection of patients who would not benefit from cognitive assessment, facilitating the allocation of human and economic resources.
Subject(s)
Cognitive Dysfunction , Humans , Aged , Middle Aged , Cross-Sectional Studies , Cognitive Dysfunction/diagnosis , Machine Learning , Decision Making , Primary Health CareABSTRACT
The systematic assessment of cognitive performance of older people without cognitive complaints is controversial and unfeasible. Identifying individuals at higher risk of cognitive impairment could optimize resource allocation. We aimed to develop and test machine learning models to predict cognitive impairment using variables obtainable in primary care settings. In this cross-sectional study, we included 8,291 participants of the baseline assessment of the ELSA-Brasil study, who were aged between 50 and 74 years and were free of dementia. Cognitive performance was assessed with a neuropsychological battery and cognitive impairment was defined as global cognitive z-score below 2 standard deviations. Variables used as input to the prediction models included demographics, social determinants, clinical conditions, family history, lifestyle, and laboratory tests. We developed machine learning models using logistic regression, neural networks, and gradient boosted trees. Participants' mean age was 58.3±6.2 years, 55% were female. Cognitive impairment was present in 328 individuals (4%). Machine learning algorithms presented fair to good discrimination (areas under the ROC curve between 0.801 and 0.873). Extreme Gradient Boosting presented the highest discrimination, high specificity (97%), and negative predictive value (97%). Seventy-six percent of the individuals with cognitive impairment were included among the highest ranked individuals by this algorithm. In conclusion, we developed and tested a machine learning model to predict cognitive impairment based on primary care data that presented good discrimination and high specificity. These characteristics could support the detection of patients who would not benefit from cognitive assessment, facilitating the allocation of human and economic resources.
ABSTRACT
Yeasts capable of growth on xylose were isolated from macaúba (Acrocomia aculeata) fruit, a Brazilian palm tree with great potential for use as biodiesel feedstock production. Candida boidinii UFMG14 strain achieved the highest ethanol production (5 g/L) and was chosen to ferment macaúba presscake hemicellulosic hydrolysate (MPHH). The MPHH was produced by the first time in this work and the resultant fivefold concentrate showed considerable sugar content (52.3 and 34.2 g/L xylose and glucose, respectively) and low furfural (0.01 g/L) and hydroxymethylfurfural (0.15 g/L) concentrations. C. boidinii UFMG14 fermentation was evaluated in supplemented and non-supplemented MPHH containing either 10 or 25 g/L of xylose. The maximum ethanol production (12 g/L) was observed after 48 h of fermentation. The ethanol yield was significantly affected by supplementation and concentration of MPHH while ethanol productivity was affected only by MPHH concentration. This is the first study demonstrating theC. boidinii potential for ethanol production from hemicellulose byproducts.