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1.
Sci Rep ; 14(1): 8561, 2024 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-38609468

RESUMEN

Trauma scientists have raised the alarm about the devastating consequences of the Ukraine war on mental health. We examined how higher education students-as indirect victims-coped with this conflict and how they emotionally reacted during 2022. We involved 2314 students from 16 countries through an online survey. A structural equation model indicated significant relations between war-related worry about military and macroeconomics domains and two coping strategies (opposition, support giving), in turn significantly linked with six emotions. The model was strongly invariant across gender, study field, and geographic area. The most frequent emotions were anger and anxiety, followed by two future-centred emotions (hopelessness and hope). Emotions were more frequent for females and students of the countries geographically close to the war region. Our findings call for evidence-based policy recommendations to be implemented by institutions to combat the negative short and long-term psychological sequelae of being witnesses of armed conflicts.


Asunto(s)
Ansiedad , Emociones , Femenino , Humanos , Ucrania , Habilidades de Afrontamiento , Estudiantes
2.
J Clin Exp Dent ; 16(2): e111-e123, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38496810

RESUMEN

Background: The 24-month clinical performance of 3 commercially available flowable bulk-fill resin composites in Class III restorations was evaluated. Material and Methods: Forty-two patients, 27 females (64.3%) and 15 (35.7%) males, received at least 3 Class III restorations that never exceeded 4 mm depth and width. One hundred thirty-eight teeth, divided up into three groups (n=46), were randomly restored with Admira Fusion x-base (AFB), Estelite Bulk Fill Flow (EBF) and SDR flow+ (SDR) in one single increment. A 2-step self-etch adhesive system Clearfil SE Bond (C-SE) with selective enamel etching was used for all restorations. The restorations were clinically evaluated using a slightly modified USPHS criteria at the baseline and every 6 months for 24 months. Success rates of each material between the baseline and at 24 months were compared with the McNemar test. At each timepoint, the comparison of the clinical performance among materials in terms of the ratings of the considered criteria was analyzed by using the Friedman and Cochran's Q tests. Results: At the end of the 24-month follow-up, the overall clinical success rate was 100% for each tested material. However, significant differences among the composites were highlighted for several criteria involving the marginal adaptation, marginal discoloration, surface texture, surface staining and color match. Conclusions: The flowable bulk-fill resin composites tested showed an overall good effectiveness for Class III restorations after the 24 months, although significant rating differences among the materials emerged for some specific clinical criteria. Key words:Bulk-fill, Class III restoration, flowable composite, clinical study, self-etching adhesive.

3.
Neurol Sci ; 44(12): 4465-4472, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37436558

RESUMEN

BACKGROUND: It is well established that trigeminal neuralgia is more prevalent in females than in males. Neurovascular compression with morphological changes of the trigeminal root represents the most recognized etiological factor. However, other factors may play a role in the framework of a multi-hit model. The primary aim of this study was to investigate sex differences in radiological and clinical characteristics of trigeminal neuralgia to better understand the multifactorial origin of this peculiar neuropathic pain condition. METHODS: In this cross-sectional study patients with a definite diagnosis of primary trigeminal neuralgia were consecutively enrolled. Each patient underwent 3T MRI with sequences dedicated to the study of neurovascular compression. Major morphological changes of the trigeminal root were quantitatively assessed. Clinical characteristics were systematically collected through a dedicated questionnaire. A logistic regression model was implemented to predict radiological and clinical characteristics based on sex. RESULTS: A total of 114 patients with classical (87) or idiopathic trigeminal neuralgia (27) were enrolled. Female sex was predictive for idiopathic trigeminal neuralgia. Male sex was predictive, among the comorbidities and clinical characteristics, for hypertension, the involvement of the left side and the second trigeminal division, alone or with the ophthalmic division. DISCUSSION: The preponderance of TN in the female sex and the association between idiopathic TN and the female sex suggest the role of additional etiological factors in the framework of a multi-hit model. The identification of clinical variables predicted by sex suggests the possibility that distinct phenotypes, with peculiar pathophysiological and therapeutic aspects, may occur in females and males.


Asunto(s)
Neuralgia del Trigémino , Humanos , Masculino , Femenino , Neuralgia del Trigémino/diagnóstico por imagen , Neuralgia del Trigémino/epidemiología , Caracteres Sexuales , Estudios Transversales , Radiografía , Imagen por Resonancia Magnética , Nervio Trigémino
4.
Front Public Health ; 10: 974505, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36211660

RESUMEN

Sustainability of cancer burden is becoming increasingly central in the policy makers' debate, and poses a challenge for the welfare systems, due to trends towards greater intensity of healthcare service use, which imply increasing costs of cancer care. Measuring and projecting the economic burden associated with cancer and identifying effective policies for minimising its impact are important issues for healthcare systems. Scope of this paper is to illustrate a novel comprehensive approach (called Epicost) to the estimation of the economic burden of cancer, based on micro-data collected from multiple data sources. It consists of a model of cost analysis to estimate the amount of reimbursement payed by the National Health Service to health service providers (hospitals, ambulatories, pharmacies) for the expenses incurred in the diagnoses and treatments of a cohort of cancer patients; these cancer costs are estimated in various phases of the disease reflecting patients' patterns of care: initial, monitoring and final phase. The main methodological features are illustrated using a cohort of colon cancer cases from a Cancer Registry in Italy. This approach has been successfully implemented in Italy and it has been adapted to other European countries, such as Belgium, Norway and Poland in the framework of the Innovative Partnership for Action Against Cancer (iPAAC) Joint Action, sponsored by the European Commission. It is replicable in countries/regions where population-based cancer registry data is available and linkable at individual level with administrative data on costs of care.


Asunto(s)
Neoplasias , Medicina Estatal , Europa (Continente) , Hospitales , Humanos , Italia/epidemiología , Neoplasias/terapia
5.
Clin Neurophysiol ; 142: 52-58, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35970059

RESUMEN

OBJECTIVE: In this clinical and neurophysiological study, we aimed to test trigeminal nerve fibre function in patients with trigeminal neuralgia, with and without concomitant continuous pain. METHODS: We enrolled 65 patients with a definite diagnosis of primary trigeminal neuralgia. Patients were grouped according to whether they experienced purely paroxysmal pain (36) or also had concomitant continuous pain (29). All participants underwent trigeminal reflex testing to assess the function of large non-nociceptive myelinated fibres and laser-evoked potentials to assess the function of small myelinated Aδ and unmyelinated C fibres. Neurophysiological examiners were blinded to the affected side. RESULTS: The only neurophysiological abnormality distinguishing the two groups of patients was the side asymmetry of C fibre-related laser-evoked potential amplitude (p = 0.005), which was higher in patients with concomitant continuous pain than in patients with purely paroxysmal pain (indicative of a reduced C fibre-related laser-evoked potential amplitude in the affected side of patients with concomitant continuous pain). CONCLUSIONS: Our clinical and neurophysiological study indicates that in patients with trigeminal neuralgia concomitant continuous pain is associated with unmyelinated C fibre damage as assessed with laser-evoked potentials. SIGNIFICANCE: Our findings suggest that concomitant continuous pain is related to unmyelinated C fibre loss, possibly triggering abnormal activity in denervated trigeminal second-order neurons.


Asunto(s)
Potenciales Evocados por Láser , Neuralgia del Trigémino , Humanos , Fibras Nerviosas Amielínicas/fisiología , Dolor , Reflejo , Nervio Trigémino , Neuralgia del Trigémino/diagnóstico
6.
Learn Instr ; 80: 101629, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35578734

RESUMEN

The outbreak of the COVID-19 pandemic has had a wide range of negative consequences for higher education students. We explored the generalizability of the control-value theory of achievement emotions for e-learning, focusing on their antecedents. We involved 17019 higher education students from 13 countries, who completed an online survey during the first wave of the pandemic. A structural equation model revealed that proximal antecedents (e-learning self-efficacy, computer self-efficacy) mediated the relation between environmental antecedents (cognitive and motivational quality of the task) and positive and negative achievement emotions, with some exceptions. The model was invariant across country, area of study, and gender. The rates of achievement emotions varied according to these same factors. Beyond their theoretical relevance, these findings could be the basis for policy recommendations to support stakeholders in coping with the challenges of e-learning and the current and future sequelae of the pandemic.

7.
Br J Math Stat Psychol ; 75(2): 334-362, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35132613

RESUMEN

The Plackett-Luce model (PL) for ranked data assumes the forward order of the ranking process. This hypothesis postulates that the ranking process of the items is carried out by sequentially assigning the positions from the top (most liked) to the bottom (least liked) alternative. This assumption has been recently relaxed with the Extended Plackett-Luce model (EPL) through the introduction of the discrete reference order parameter, describing the rank attribution path. By starting from two formal properties of the EPL, the former related to the inverse ordering of the item probabilities at the first and last stage of the ranking process and the latter well-known as independence of irrelevant alternatives (or Luce's choice axiom), we derive novel diagnostic tools for testing the appropriateness of the EPL assumption as the actual sampling distribution of the observed rankings. These diagnostic tools can help uncovering possible idiosyncratic paths in the sequential choice process. Besides contributing to fill the gap of goodness-of-fit methods for the family of multistage models, we also show how one of the two statistics can be conveniently exploited to construct a heuristic method, that surrogates the maximum likelihood approach for inferring the underlying reference order parameter. The relative performance of the proposals, compared with more conventional approaches, is illustrated by means of extensive simulation studies.


Asunto(s)
Funciones de Verosimilitud , Simulación por Computador
8.
PLoS One ; 16(10): e0258807, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34669757

RESUMEN

The outbreak of the COVID-19 pandemic has dramatically shaped higher education and seen the distinct rise of e-learning as a compulsory element of the modern educational landscape. Accordingly, this study highlights the factors which have influenced how students perceive their academic performance during this emergency changeover to e-learning. The empirical analysis is performed on a sample of 10,092 higher education students from 10 countries across 4 continents during the pandemic's first wave through an online survey. A structural equation model revealed the quality of e-learning was mainly derived from service quality, the teacher's active role in the process of online education, and the overall system quality, while the students' digital competencies and online interactions with their colleagues and teachers were considered to be slightly less important factors. The impact of e-learning quality on the students' performance was strongly mediated by their satisfaction with e-learning. In general, the model gave quite consistent results across countries, gender, study fields, and levels of study. The findings provide a basis for policy recommendations to support decision-makers incorporate e-learning issues in the current and any new similar circumstances.


Asunto(s)
Rendimiento Académico , COVID-19/epidemiología , Educación a Distancia , Pandemias , SARS-CoV-2 , Adolescente , Adulto , Femenino , Humanos , Masculino
9.
Eur J Pain ; 25(8): 1815-1828, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33982830

RESUMEN

BACKGROUND: Although non-suicidal self-injury (NSSI) disorder is highly prevalent in adolescents, its relationship with pain system function and suicidality is still controversial. The present study was designed to assess the function of the nociceptive afferent pathways and the endogenous pain modulation in adolescent patients with NSSI and to longitudinally register any suicide attempt, describe its frequency and find a possible association between suicide, neurophysiological measures and psychological measures. METHODS: We enrolled 30 adolescents suffering from NSSI and 20 age- and gender-matched healthy controls. Patients underwent a comprehensive psychological evaluation. Each participant underwent thermal pain thresholds of the quantitative sensory testing, laser-evoked potential recording to study the ascending nociceptive pathway and the conditioned pain modulation testing to test the endogenous pain modulation. RESULTS: We found that patients with NSSI had a reduced amplitude of the N2 component of laser-evoked potentials and an abnormal conditioned pain modulation. The amplitude of the N2 was associated with suicidal risk. CONCLUSIONS: The deficit of the endogenous pain modulation likely depends on a saturation due to continuous pain solicitation. The strong association of a reduced amplitude of the N2 component with suicide suggests that it may serve as a possible biomarker in self-harming adolescents. SIGNIFICANCE: The present study identifies the N2 component of laser-evoked potentials as a possible neurophysiological biomarker of suicidal risk in patients with non-suicidal self-injury, therefore, raising the possibility for a non-invasive test to identify subjects at higher risk of suicide among self-harming patients.


Asunto(s)
Conducta Autodestructiva , Ideación Suicida , Adolescente , Electrodos , Humanos , Dolor , Factores de Riesgo , Conducta Autodestructiva/epidemiología
10.
Eur J Pain ; 25(5): 1064-1071, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33428801

RESUMEN

BACKGROUND: It is widely agreed that carbamazepine and oxcarbazepine are highly effective in the long-term treatment of trigeminal neuralgia. However, the tolerability of these drugs across the different aetiologies of trigeminal neuralgia is still undetermined. METHODS: In this retrospective, real-world study, we assessed the effectiveness and tolerability of carbamazepine and oxcarbazepine in a large cohort of patients with classical (254 patients), secondary (60 patients) and idiopathic (40 patients) trigeminal neuralgia. We analysed data using a propensity score analysis to account for selection bias; frequencies of side effects associated with carbamazepine and oxcarbazepine were calculated by adjusting data with the inverse probability of treatment weighting. RESULTS: The initial proportion of responders was 88.3% with carbamazepine, and 90.9% with oxcarbazepine. The number of refractory patients was significantly higher in idiopathic (15%) and secondary forms (27%) than in classical trigeminal neuralgia (6%; p < .05). In 53 patients treated with carbamazepine (29.6%) and in 22 treated with oxcarbazepine (12.6%), major side effects caused treatment interruption or dosage reduction to an unsatisfactory level. Side effects occurred more frequently in patients treated with carbamazepine (43.6%) than with oxcarbazepine (30.3%, p < .0001). The frequency of treatment discontinuation was higher in patients with secondary and idiopathic forms than in those with classical trigeminal neuralgia (p < .05). CONCLUSIONS: Our real-world study shows that carbamazepine and oxcarbazepine are effective in most patients with trigeminal neuralgia; nevertheless, side effects are still a major issue, particularly in patients with secondary and idiopathic trigeminal neuralgia. SIGNIFICANCE: Although carbamazepine and oxcarbazepine are effective in most patients with trigeminal neuralgia, their side effects are still a major issue, thus necessitating the development of better-tolerated drugs.


Asunto(s)
Neuralgia del Trigémino , Anticonvulsivantes/efectos adversos , Benzodiazepinas/uso terapéutico , Carbamazepina/efectos adversos , Humanos , Oxcarbazepina , Estudios Retrospectivos , Neuralgia del Trigémino/tratamiento farmacológico
11.
Muscle Nerve ; 63(1): 68-74, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32996600

RESUMEN

BACKGROUND: We aimed at evaluating the differential involvement of large myelinated Aß-, small myelinated Aδ-, and unmyelinated C-fibers in patients with diabetic polyneuropathy and how they contribute to neuropathic pain. METHODS: We collected clinical and diagnostic test variables in 133 consecutive patients with diabetic polyneuropathy. All patients underwent Aß-fiber mediated nerve conduction study, Aδ-fiber mediated laser-evoked potentials and skin biopsy mainly assessing unmyelinated C-fibers. RESULTS: Pure large-fiber and small-fiber polyneuropathy were relatively uncommon; conversely mixed-fiber polyneuropathy was the most common type of diabetic polyneuropathy (74%). The frequency of neuropathic pain was similar in the three different polyneuropathies. Ongoing burning pain and dynamic mechanical allodynia were similarly associated with specific small-fiber related variables. CONCLUSIONS: Diabetic polyneuropathy mainly manifests as a mixed-fiber polyneuropathy, simultaneously involving Aß-, Aδ-, and C-fibers. In most patients, neuropathic pain is distinctly associated with small-fiber damage. The evidence that the frequency of neuropathic pain does not differ across pure large-, pure small-, and mixed-fiber polyneuropathy, raises the possibility that in patients with pure large-fiber polyneuropathy nociceptive nerve terminal involvement might be undetected by standard diagnostic techniques.


Asunto(s)
Neuropatías Diabéticas/patología , Hiperalgesia/patología , Fibras Nerviosas Mielínicas/patología , Fibras Nerviosas Amielínicas/patología , Neuralgia/patología , Adulto , Anciano , Diabetes Mellitus/patología , Femenino , Humanos , Hiperalgesia/fisiopatología , Masculino , Persona de Mediana Edad , Vaina de Mielina/patología , Piel/inervación , Piel/patología
12.
Eur J Pain ; 24(10): 1923-1931, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32735696

RESUMEN

OBJECTIVES: We aimed to investigate the conduction velocity of the cold spinal pathway in healthy humans. METHODS: Using a cold stimulator consisting of micro-Peltier elements that was able to produce steep cooling ramps up to -300°C/s, we recorded cold-evoked potentials after stimulation of the dorsal midline at C5, T2, T6 and T10 vertebral levels and calculated the conduction velocity of the cold spinal pathway. In all participants, we used laser stimulation to deliver painful heat (Aδ-fibres-mediated) and warm (C-fibres-mediated) stimuli to the same sites in order to compare the conduction velocity of the cold spinal pathway with that of the nociceptive and warm spinal pathways. RESULTS: Cold stimulation evoked large-amplitude vertex potentials from all stimulation sites. The mean conduction velocity of the cold spinal pathway was 12.0 m/s, which did not differ from that of the nociceptive spinal pathway (10.5 m/s). The mean conduction velocity of the warm spinal pathway was 2.0 m/s. DISCUSSION: This study provides previously unreported findings regarding cold spinal pathway conduction velocity in humans that may be useful in the assessment of spinal cord lesions as well as in intraoperative monitoring during spinal surgery. SIGNIFICANCE: This neurophysiological study provides previously unreported findings on cold spinal pathway conduction velocity in healthy humans. Cold-evoked potentials may represent an alternative to laser-evoked potential recording, useful to assess spinothalamic tract in patients with spinal cord lesions and monitor patients during spinal surgery.


Asunto(s)
Conducción Nerviosa , Tractos Espinotalámicos , Encéfalo , Potenciales Evocados , Humanos , Dolor , Médula Espinal
13.
Int J Mol Sci ; 21(14)2020 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-32708286

RESUMEN

Lung involvement is related to the natural history of anti-citrullinated proteins antibodies (ACPA)-positive rheumatoid arthritis (RA), both during the pathogenesis of the disease and as a site of disease-related injury. Increasing evidence suggests that there is a subclinical, early lung involvement during the course of the disease, even before the onset of articular manifestations, which can potentially progress to a symptomatic interstitial lung disease. To date, reliable, non-invasive markers of subclinical lung involvement are still lacking in clinical practice. The aim of this study is to evaluate the diagnostic potential of functional assessment and serum biomarkers in the identification of subclinical lung involvement in ACPA-positive subjects. Fifty ACPA-positive subjects with or without confirmed diagnosis of RA (2010 ARC-EULAR criteria) were consecutively enrolled. Each subject underwent clinical evaluation, pulmonary function testing (PFT) with assessment of diffusion lung capacity for carbon monoxide (DLCO), cardiopulmonary exercise testing (CPET), surfactant protein D (SPD) serum levels dosage and high-resolution computed tomography (HRCT) of the chest. The cohort was composed of 21 ACPA-positive subjects without arthritis (ND), 10 early (disease duration < 6 months, treatment-naïve) RA (ERA) and 17 long-standing (disease duration < 36 months, on treatment) RA (LSRA). LSRA patients had a significantly higher frequency of overall HRCT abnormalities compared to the other groups (p = 0.001). SPD serum levels were significantly higher in ACPA-positive subjects compared with healthy controls (158.5 ± 132.3 ng/mL vs 61.27 ± 34.11 ng/mL; p < 0.0001) and showed an increasing trend from ND subjects to LSRD patients (p = 0.004). Patients with HRCT abnormalities showed significantly lower values of DLCO (74.19 ± 13.2% pred. vs 131.7 ± 93% pred.; p = 0.009), evidence of ventilatory inefficiency at CPET and significantly higher SPD serum levels compared with subjects with no HRCT abnormalities (213.5 ± 157.2 ng/mL vs 117.7 ± 157.3 ng/mL; p = 0.018). Abnormal CPET responses and higher SPD levels were also associated with specific radiological findings. Impaired DLCO and increased SPD serum levels were independently associated with the presence of HRCT abnormalities. Subclinical lung abnormalities occur early in RA-associated autoimmunity. The presence of subclinical HRCT abnormalities is associated with several functional abnormalities and increased SPD serum levels of SPD. Functional evaluation through PFT and CPET, together with SPD assessment, may have a diagnostic potential in ACPA-positive subjects, contributing to the identification of those patients to be referred to HRCT scan.


Asunto(s)
Anticuerpos Antiproteína Citrulinada/sangre , Artritis Reumatoide/sangre , Prueba de Esfuerzo/métodos , Enfermedades Pulmonares Intersticiales/sangre , Pulmón/fisiopatología , Adulto , Anticuerpos Antiproteína Citrulinada/inmunología , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/inmunología , Autoinmunidad , Biomarcadores/sangre , Estudios de Cohortes , Femenino , Humanos , Pulmón/diagnóstico por imagen , Enfermedades Pulmonares Intersticiales/diagnóstico , Enfermedades Pulmonares Intersticiales/inmunología , Masculino , Persona de Mediana Edad , Proteína D Asociada a Surfactante Pulmonar/sangre , Pruebas de Función Respiratoria , Factor Reumatoide/sangre , Tomografía Computarizada por Rayos X
14.
Minerva Cardioangiol ; 67(1): 73-78, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29808977

RESUMEN

BACKGROUND: Rapid effective triage is integral to emergency care in patients hospitalized for heart failure, to guide the type and intensity of therapy. Several indexes and scores have been proposed to predict outcome; most of the them are complex and unfit to use at the bedside. METHODS: We propose a new prognostic index for in hospital mortality in acute heart failure. The index is calculated using the following formula: 220 - age - heart rate + systolic blood pressure - (creatinine ×10). The index was tested in 1628 patients admitted for acute heart failure and enrolled, from November 2007 to December 2009, in the Italian Registry on Heart Failure Outcome (IN-HF); a prospective, multicenter, observational study. RESULTS: The prognostic index was an independent predictor for in hospital mortality risk (AUC=0.74, P<0.0001), together with left ventricular ejection fraction (P=0.001), glycemia (P=0.019) and hemoglobin concentration (P=0.002). CONCLUSIONS: A simple prognostic index based on variables easily assessed can be useful to predict mortality in acute heart failure at the first arrival in hospital. The new index is independent from the left ventricular ejection fraction.


Asunto(s)
Algoritmos , Insuficiencia Cardíaca/diagnóstico , Pronóstico , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Presión Sanguínea , Creatinina/sangre , Femenino , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sistema de Registros , Triaje
15.
Psychometrika ; 82(2): 442-458, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-27734294

RESUMEN

The elicitation of an ordinal judgment on multiple alternatives is often required in many psychological and behavioral experiments to investigate preference/choice orientation of a specific population. The Plackett-Luce model is one of the most popular and frequently applied parametric distributions to analyze rankings of a finite set of items. The present work introduces a Bayesian finite mixture of Plackett-Luce models to account for unobserved sample heterogeneity of partially ranked data. We describe an efficient way to incorporate the latent group structure in the data augmentation approach and the derivation of existing maximum likelihood procedures as special instances of the proposed Bayesian method. Inference can be conducted with the combination of the Expectation-Maximization algorithm for maximum a posteriori estimation and the Gibbs sampling iterative procedure. We additionally investigate several Bayesian criteria for selecting the optimal mixture configuration and describe diagnostic tools for assessing the fitness of ranking distributions conditionally and unconditionally on the number of ranked items. The utility of the novel Bayesian parametric Plackett-Luce mixture for characterizing sample heterogeneity is illustrated with several applications to simulated and real preference ranked data. We compare our method with the frequentist approach and a Bayesian nonparametric mixture model both assuming the Plackett-Luce model as a mixture component. Our analysis on real datasets reveals the importance of an accurate diagnostic check for an appropriate in-depth understanding of the heterogenous nature of the partial ranking data.


Asunto(s)
Algoritmos , Teorema de Bayes , Psicometría , Humanos , Probabilidad
16.
Heart Vessels ; 30(3): 325-30, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-24658885

RESUMEN

To propose a clinical prognostic index for death and heart failure in patients with ischemic cardiomyopathy implanted with an ICD. This prospective study included 192 consecutive patients (age 68 ± 10) recruited from 2004 to 2009 and implanted with an ICD for MADIT II criteria. All patients performed 24-h ambulatory blood pressure monitoring after discharge and common haematological samples. The prognostic index (PI) was built according to the formula: 120 - age + mean 24 h systolic blood pressure--(creatinine 9 10). Other variables were assessed: EF, haemoglobin concentration, mean 24 h heart rate and diastolic blood pressure, sodium level, pacing mode and diabetes. Non-arrhythmic cardiac death and new hospitalizations for heart failure during 1-year follow-up were the combined end point. A total of 48 events (25%) occurred during the follow-up: 7 cardiac deaths and 41 hospitalizations for acute heart failure. Cox proportional hazards model showed that PI was the only predictor of events (HR = 0.96; CI 95% 0.944­0.976, p < 0.0001). ROC curve showed that PI best cut-off was 144, with AUC 0.79, p < 0.0001; sensitivity 77%, specificity 74%, positive predictive value 50%, negative predictive value 90%. PI was predictive of events in a clinical setting where EF had no predictive value. PI works according to the rule ''the lower the worse''. The high negative predictive value (90%) of PI allows to identify subjects at lower risk for death and heart failure. PI can be a practical tool to stratify risk in ischemic cardiomyopathy.


Asunto(s)
Cardiomiopatías/terapia , Técnicas de Apoyo para la Decisión , Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Insuficiencia Cardíaca/terapia , Modelos Biológicos , Isquemia Miocárdica/complicaciones , Enfermedad Aguda , Anciano , Biomarcadores/sangre , Presión Sanguínea , Monitoreo Ambulatorio de la Presión Arterial , Cardiomiopatías/diagnóstico , Cardiomiopatías/etiología , Cardiomiopatías/mortalidad , Cardiomiopatías/fisiopatología , Creatinina/sangre , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca , Hospitalización , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/mortalidad , Isquemia Miocárdica/fisiopatología , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Sodio/sangre , Volumen Sistólico , Factores de Tiempo , Resultado del Tratamiento , Función Ventricular Izquierda
17.
Stat Med ; 33(21): 3738-58, 2014 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-24903256

RESUMEN

We propose the use of probability models for ranked data as a useful alternative to a quantitative data analysis to investigate the outcome of bioassay experiments when the preliminary choice of an appropriate normalization method for the raw numerical responses is difficult or subject to criticism. We review standard distance-based and multistage ranking models and propose an original generalization of the Plackett-Luce model to account for the order of the ranking elicitation process. The usefulness of the novel model is illustrated with its maximum likelihood estimation for a real data set. Specifically, we address the heterogeneous nature of the experimental units via model-based clustering and detail the necessary steps for a successful likelihood maximization through a hybrid version of the expectation-maximization algorithm. The performance of the mixture model using the new distribution as mixture components is then compared with alternative mixture models for random rankings. A discussion on the interpretation of the identified clusters and a comparison with more standard quantitative approaches are finally provided.


Asunto(s)
Algoritmos , Análisis por Conglomerados , Interpretación Estadística de Datos , Funciones de Verosimilitud , Modelos Estadísticos , Simulación por Computador , Humanos
18.
J Cardiovasc Med (Hagerstown) ; 12(5): 334-9, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21487343

RESUMEN

AIMS: Evaluation of ambulatory blood pressure monitoring (ABPM), two-dimensional (2D) echo and clinical variables in predicting cardiac death and acute decompensated heart failure in patients with ischaemic cardiomyopathy and receiving a cardioverter-defibrillator implantation. METHODS AND RESULTS: We studied 180 consecutive patients (169 men) on an out-patient basis, with systolic dysfunction (ejection fraction ≤35%) and previous myocardial infarction. All received a cardioverter defibrillator (ICD) (116 dual chamber, 36 monocameral and 28 biventricular), for primary prevention of sudden death and standard medical therapy for heart failure. Mean follow-up was 11.7 months. Two-dimensional echo was performed just before ICD implantation, ABPM and haematological samples 2 weeks later. Age, ejection fraction, creatinine, haemoglobin concentration, mean 24-h systolic blood pressure, mean 24-h diastolic blood pressure, mean 24-h heart rate, brain natriuretic peptide, QRS duration, % paced beats, ventricular scar, biventricular pacing, sex and diabetes were considered. Cox proportional hazards regression analysis was used to explore the relationship between events. ROC curves were built for each independent variable. Events occurred in 47 patients (26%); 7 deaths for refractory heart failure and 40 hospitalizations for acute decompensated heart failure. Low mean 24-h systolic blood pressure [hazard ratio 0.96, 95% confidence interval (CI) 0.93-0.99, P = 0.02], high creatinine (hazard ratio 1.61, 95% CI 1.06-2.47, P = 0.01), low haemoglobin concentration (hazard ratio 0.81, 95% CI 0.65-0.99, P = 0.04) and older age (hazard ratio 1.04, 95% CI 1.01-1.08, P = 0.02) were independent predictors of events. CONCLUSIONS: Ambulatory systolic blood pressure, haemoglobin, creatinine and age can stratify risk of death and acute decompensated heart failure in patients with ischaemic cardiomyopathy and ICD in whom 2D-echo ejection fraction is not predictive.


Asunto(s)
Monitoreo Ambulatorio de la Presión Arterial , Presión Sanguínea , Cardiomiopatías/terapia , Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables , Ecocardiografía , Cardioversión Eléctrica/instrumentación , Insuficiencia Cardíaca/terapia , Isquemia Miocárdica/complicaciones , Factores de Edad , Anciano , Biomarcadores/sangre , Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/etiología , Cardiomiopatías/mortalidad , Cardiomiopatías/fisiopatología , Distribución de Chi-Cuadrado , Creatinina/sangre , Muerte Súbita Cardíaca/etiología , Progresión de la Enfermedad , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Hemoglobinas/análisis , Humanos , Italia , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/mortalidad , Isquemia Miocárdica/fisiopatología , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Medición de Riesgo , Factores de Riesgo , Volumen Sistólico , Sístole , Factores de Tiempo , Resultado del Tratamiento , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/fisiopatología , Disfunción Ventricular Izquierda/terapia , Función Ventricular Izquierda
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