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Growing evidence suggests that sustained concentrated urine contributes to chronic metabolic and kidney diseases. Recent results indicate that a daily urinary concentration of 500 mOsm/kg reflects optimal hydration. This study aims at providing personalized advice for daily water intake considering personal intrinsic (age, sex, height, weight) and extrinsic (food and fluid intakes) characteristics to achieve a target urine osmolality (UOsm) of 500 mOsm/kg using machine learning and optimization algorithms. Data from clinical trials on hydration (four randomized and three non-randomized trials) were analyzed. Several machine learning methods were tested to predict UOsm. The predictive performance of the developed algorithm was evaluated against current dietary guidelines. Features linked to urine production and fluid consumption were listed among the most important features with relative importance values ranging from 0.10 to 0.95. XGBoost appeared the most performing approach (Mean Absolute Error (MAE) = 124.99) to predict UOsm. The developed algorithm exhibited the highest overall correct classification rate (85.5%) versus that of dietary guidelines (77.8%). This machine learning application provides personalized advice for daily water intake to achieve optimal hydration and may be considered as a primary prevention tool to counteract the increased incidence of chronic metabolic and kidney diseases.
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Ingestión de Líquidos , Aprendizaje Automático , Adulto , Humanos , Algoritmos , Política Nutricional , Concentración Osmolar , Ensayos Clínicos Controlados Aleatorios como Asunto , Ensayos Clínicos Controlados no Aleatorios como AsuntoRESUMEN
Industrial statistics plays a major role in the areas of both quality management and innovation. However, existing methodologies must be integrated with the latest tools from the field of Artificial Intelligence. To this end, a background on the joint application of Design of Experiments (DOE) and Machine Learning (ML) methodologies in industrial settings is presented here, along with a case study from the chemical industry. A DOE study is used to collect data, and two ML models are applied to predict responses which performance show an advantage over the traditional modeling approach. Emphasis is placed on causal investigation and quantification of prediction uncertainty, as these are crucial for an assessment of the goodness and robustness of the models developed. Within the scope of the case study, the models learned can be implemented in a semi-automatic system that can assist practitioners who are inexperienced in data analysis in the process of new product development.
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The efficacy of hydroxychloroquine (HCQ) in treating SARS-CoV-2 infection is harshly debated, with observational and experimental studies reporting contrasting results. To clarify the role of HCQ in Covid-19 patients, we carried out a retrospective observational study of 4,396 unselected patients hospitalized for Covid-19 in Italy (February-May 2020). Patients' characteristics were collected at entry, including age, sex, obesity, smoking status, blood parameters, history of diabetes, cancer, cardiovascular and chronic pulmonary diseases, and medications in use. These were used to identify subtypes of patients with similar characteristics through hierarchical clustering based on Gower distance. Using multivariable Cox regressions, these clusters were then tested for association with mortality and modification of effect by treatment with HCQ. We identified two clusters, one of 3,913 younger patients with lower circulating inflammation levels and better renal function, and one of 483 generally older and more comorbid subjects, more prevalently men and smokers. The latter group was at increased death risk adjusted by HCQ (HR[CI95%] = 3.80[3.08-4.67]), while HCQ showed an independent inverse association (0.51[0.43-0.61]), as well as a significant influence of cluster∗HCQ interaction (p < 0.001). This was driven by a differential association of HCQ with mortality between the high (0.89[0.65-1.22]) and the low risk cluster (0.46[0.39-0.54]). These effects survived adjustments for additional medications in use and were concordant with associations with disease severity and outcome. These findings suggest a particularly beneficial effect of HCQ within low risk Covid-19 patients and may contribute to clarifying the current controversy on HCQ efficacy in Covid-19 treatment.
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Antimaláricos/efectos adversos , Antimaláricos/uso terapéutico , Tratamiento Farmacológico de COVID-19 , COVID-19/mortalidad , Mortalidad Hospitalaria , Hidroxicloroquina/efectos adversos , Hidroxicloroquina/uso terapéutico , Anciano , Anciano de 80 o más Años , COVID-19/fisiopatología , Análisis por Conglomerados , Femenino , Humanos , Italia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , SARS-CoV-2/efectos de los fármacos , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
Background: Protease inhibitors have been considered as possible therapeutic agents for COVID-19 patients. Objectives: To describe the association between lopinavir/ritonavir (LPV/r) or darunavir/cobicistat (DRV/c) use and in-hospital mortality in COVID-19 patients. Study Design: Multicenter observational study of COVID-19 patients admitted in 33 Italian hospitals. Medications, preexisting conditions, clinical measures, and outcomes were extracted from medical records. Patients were retrospectively divided in three groups, according to use of LPV/r, DRV/c or none of them. Primary outcome in a time-to event analysis was death. We used Cox proportional-hazards models with inverse probability of treatment weighting by multinomial propensity scores. Results: Out of 3,451 patients, 33.3% LPV/r and 13.9% received DRV/c. Patients receiving LPV/r or DRV/c were more likely younger, men, had higher C-reactive protein levels while less likely had hypertension, cardiovascular, pulmonary or kidney disease. After adjustment for propensity scores, LPV/r use was not associated with mortality (HR = 0.94, 95% CI 0.78 to 1.13), whereas treatment with DRV/c was associated with a higher death risk (HR = 1.89, 1.53 to 2.34, E-value = 2.43). This increased risk was more marked in women, in elderly, in patients with higher severity of COVID-19 and in patients receiving other COVID-19 drugs. Conclusions: In a large cohort of Italian patients hospitalized for COVID-19 in a real-life setting, the use of LPV/r treatment did not change death rate, while DRV/c was associated with increased mortality. Within the limits of an observational study, these data do not support the use of LPV/r or DRV/c in COVID-19 patients.
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INTRODUCTION: A hypercoagulable condition was described in patients with coronavirus disease 2019 (COVID-19) and proposed as a possible pathogenic mechanism contributing to disease progression and lethality. AIM: We evaluated if in-hospital administration of heparin improved survival in a large cohort of Italian COVID-19 patients. METHODS: In a retrospective observational study, 2,574 unselected patients hospitalized in 30 clinical centers in Italy from February 19, 2020 to June 5, 2020 with laboratory-confirmed severe acute respiratory syndrome coronavirus-2 infection were analyzed. The primary endpoint in a time-to event analysis was in-hospital death, comparing patients who received heparin (low-molecular-weight heparin [LMWH] or unfractionated heparin [UFH]) with patients who did not. We used multivariable Cox proportional-hazards regression models with inverse probability for treatment weighting by propensity scores. RESULTS: Out of 2,574 COVID-19 patients, 70.1% received heparin. LMWH was largely the most used formulation (99.5%). Death rates for patients receiving heparin or not were 7.4 and 14.0 per 1,000 person-days, respectively. After adjustment for propensity scores, we found a 40% lower risk of death in patients receiving heparin (hazard ratio = 0.60; 95% confidence interval: 0.49-0.74; E-value = 2.04). This association was particularly evident in patients with a higher severity of disease or strong coagulation activation. CONCLUSION: In-hospital heparin treatment was associated with a lower mortality, particularly in severely ill COVID-19 patients and in those with strong coagulation activation. The results from randomized clinical trials are eagerly awaited to provide clear-cut recommendations.
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Anticoagulantes/uso terapéutico , COVID-19/complicaciones , Heparina de Bajo-Peso-Molecular/uso terapéutico , Heparina/uso terapéutico , Trombofilia/etiología , Trombofilia/prevención & control , Anciano , Coagulación Sanguínea/efectos de los fármacos , COVID-19/sangre , Femenino , Mortalidad Hospitalaria , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Análisis de Supervivencia , Trombofilia/sangre , Tratamiento Farmacológico de COVID-19RESUMEN
Very often, data collected in medical research are characterized by censored observations and/or data with mass on the value zero. This happens for example when some measurements fall below the detection limits of the specific instrument used. This type of left censored observations is called "nondetects". Such a situation of an excessive number of zeros in a data set is also referred to as zero-inflated data. In the present work, we aim at comparing different multivariate permutation procedures in two-sample testing for data with nondetects. The effect of censoring is investigated with regard to the different values that may be attributed to nondetected values, both under the null hypothesis and under alternative. We motivate the problem using data from allergy research.
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Análisis por Micromatrices/estadística & datos numéricos , Modelos Estadísticos , Simulación por Computador , Humanos , Hipersensibilidad/inmunología , Inmunoglobulina E/inmunología , Proyectos de InvestigaciónRESUMEN
The aim of the study was to characterize the audiological consequences of congenital cytomegalovirus infection (CMV) and to evaluate the outcome of rehabilitation with hearing aids and/or cochlear implant (CI), associated with an adequate speech-language therapy. A retrospective review of data was made from a total of 16 infants, affected by severe to profound hearing loss from congenital CMV infection, referred to a tertiary audiological center for rehabilitation. Audiological evaluation was performed using behavioral audiometry, auditory brainstem responses (ABR) and/or electrocochleography (ECochG). Of the 16 children (median age at diagnosis of hearing loss: 21.33 +/- 0.7 months) with CMV hearing loss, 14 were affected by profound bilateral hearing loss and received a CI, while 2 were affected by bilateral severe hearing loss and received hearing aids. Cochlear implants can provide useful speech comprehension to patients with CMV-related deafness, even if language development is lower when compared to a group of Connexin (Cx) 26+ cochlear-implanted children (eight subjects), matched for age. Congenital CMV infection still represents a serious clinical condition, as well as an important cause of hearing loss in children. More studies have claimed to identify the pathophysiological mechanisms of damage and thus to ensure a better therapeutic approach. Nonetheless, in cases of CMV-deafened babies, the overall outcome of cochlear implantation is good.
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Implantación Coclear , Infecciones por Citomegalovirus/congénito , Sordera/congénito , Sordera/rehabilitación , Audífonos , Audiometría de Respuesta Evocada , Tronco Encefálico/fisiopatología , Niño , Preescolar , Sordera/diagnóstico , Sordera/fisiopatología , Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Trastornos del Desarrollo del Lenguaje/diagnóstico , Trastornos del Desarrollo del Lenguaje/fisiopatología , Trastornos del Desarrollo del Lenguaje/rehabilitación , Masculino , Grupo de Atención al Paciente , Prueba del Umbral de Recepción del HablaRESUMEN
This paper looks at permutation methods used to deal with hypothesis testing within the survival analysis framework. In the literature, several attempts have been made to deal with the comparison of survival curves and, depending on the survival and hazard functions of two groups, they can be more or less efficient in detecting differences. Furthermore, in some situations, censoring can be informative in that it depends on treatment effect. Our proposal is based on the nonparametric combination approach and has proven to be very effective under different configurations of survival and hazard functions. It allows the practitioner to test jointly on primary and censoring events and, by using multiple testing methods, to assess the significance of the treatment effect separately on the survival and the censoring process.
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Estadísticas no Paramétricas , Análisis de Supervivencia , Interpretación Estadística de Datos , HumanosRESUMEN
Statistical tests in medical research: traditional methods vs. multivariate npc permutation tests.Within medical research, a useful statistical tool is based on hypotheses testing in terms of the so-called null, that is the treatment has no effect, and alternative hypotheses, that is the treatment has some effects. By controlling the risks of wrong decisions, empirical data are used in order to possibly reject the null hypotheses in favour of the alternative, so that demonstrating the efficacy of a treatment of interest. The multivariate permutation tests, based on the nonparametric combination - NPC method, provide an innovative, robust and effective hypotheses testing solution to many real problems that are commonly encountered in medical research when multiple end-points are observed. This paper discusses the various approaches to hypothesis testing and the main advantages of NPC tests, which consist in the fact that they require much less stringent assumptions than traditional statistical tests. Moreover, the related results may be extended to the reference population even in case of selection-bias, that is non-random sampling. In this work, we review and discuss some basic testing procedures along with the theoretical and practical relevance of NPC tests showing their effectiveness in medical research. Within the non-parametric methods, NPC tests represent the current "frontier" of statistical research, but already widely available in the practice of analysis of clinical data.
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Investigación Biomédica/estadística & datos numéricos , Modelos Estadísticos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Análisis de Varianza , Medicina Basada en la Evidencia/estadística & datos numéricos , Humanos , Italia , Análisis Multivariante , Estudios Observacionales como Asunto/estadística & datos numéricos , Estadísticas no ParamétricasRESUMEN
OBJECTIVE: The aim of the present study was to evaluate the association between temporomandibular joint (TMJ) effusion and disk displacement by means of magnetic resonance (MR) imaging. METHODS: One hundred and ninety-four patients were included in the study and underwent a bilateral MR of the TMJ at both closed mouth and maximum mouth opening positions. The association between TMJ effusion and disk displacement with or without reduction was assessed by means of 2 x 2 contingency tables and a permutation test for a categorical variable. RESULTS: The results showed a statistically significant association between joint effusion and disk displacement without reduction (DDNR) (P = .008). There was no statistically significant association between TMJ effusion and normal disk position (P = .99) or disk displacement with reduction (DDR) (P = .43). CONCLUSIONS: Although these results show a significant association between joint effusion and disk displacement without reduction, there remains uncertainty as to if the nonreducing displacement causes the effusion or vice versa. The present investigation also pointed out the absence of association between reducing disk displacement and effusion. These findings have to be put into relation with clinical and hystological findings.