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Statistical mistake

Antonio Carrascosa, Diego Yeste, Antonio Moreno-Galdó, Miquel Gussinyé, Ángel Ferrández, María Clemente, Mónica Fernández-Cancio
INTRODUCTION: Pubertal growth pattern differs according to age at pubertal growth spurt onset which occurs over a five years period (girls: 8-13 years, boys: 10-15 years). The need for more than one pubertal reference pattern has been proposed. We aimed to obtain five 1-year-age-interval pubertal patterns. SUBJECTS AND METHODS: Longitudinal (6 years of age-adult height) growth study of 1,453 healthy children to evaluate height-for-age, growth velocity-for-age and weight-for-age values...
February 20, 2018: Anales de Pediatría: Publicación Oficial de la Asociación Española de Pediatría (A.E.P.)
Maciej Skotak, Eren Alay, Namas Chandra
Measurement issues leading to the acquisition of artifact-free shock wave pressure-time profiles are discussed. We address the importance of in-house sensor calibration and data acquisition sampling rate. Sensor calibration takes into account possible differences between calibration methodology in a manufacturing facility, and those used in the specific laboratory. We found in-house calibration factors of brand new sensors differ by less than 10% from their manufacturer supplied data. Larger differences were noticeable for sensors that have been used for hundreds of experiments and were as high as 30% for sensors close to the end of their useful lifetime...
2018: Frontiers in Neurology
Cláudia Feitosa-Santana, Givago da Silva Souza, Esaú Sirius Ventura Pupo, Anderson Raiol Rodrigues, Maria Izabel Tentes Cortes, Dora Fix Ventura
Land exploitation that follows deforestation and mining can result in soil erosion and the release of mercury to the waters of rivers in the Amazon Basin. Inorganic mercury is methylated by bacteria that are present in the environment and it serves as a source of human contamination through fish consumption in the form of methylmercury. Long-term exposure to low-level methylmercury in the riverside populations can lead to nervous system alterations, some of which are visual impairments such as loss of luminance contrast sensitivity, restricted visual fields and color vision defects...
February 9, 2018: Neurotoxicology
Özge Yüce, Derya Sevinç
BACKGROUND: The aim of the study was to determine the compliance with the clinical and ultrasonographic staging of pubertal breast development in obese children. METHODS: Fifty-two obese children with Tanner stage 2 and stage 3 breast development accompanied by at least one pubertal clinical finding were included in the study. The staging of breast development was also performed according to the ultrasonographic morphostructural appearance. The subjects were then divided into subgroups according to their clinical and ultrasonographic breast stages...
January 26, 2018: Journal of Pediatric Endocrinology & Metabolism: JPEM
Tim P Morris, David J Fisher, Michael G Kenward, James R Carpenter
Quantitative evidence synthesis through meta-analysis is central to evidence-based medicine. For well-documented reasons, the meta-analysis of individual patient data is held in higher regard than aggregate data. With access to individual patient data, the analysis is not restricted to a "two-stage" approach (combining estimates and standard errors) but can estimate parameters of interest by fitting a single model to all of the data, a so-called "one-stage" analysis. There has been debate about the merits of one- and two-stage analysis...
January 18, 2018: Statistics in Medicine
Vera Schwarzer, Ina Bährend, Tizian Rosenstock, Felix R Dreyer, Peter Vajkoczy, Thomas Picht
BACKGROUND: Navigated transcranial magnetic stimulation (nTMS) is a non-invasive mapping tool to locate functional areas of the brain. While gaining importance in the preoperative planning process in motor eloquent regions, its usefulness for reliably identifying language areas is still being discussed. The aim of this study was to identify biometric factors which might influence and therefore bias the results of repetitive nTMS (rnTMS) over cortex areas relevant for language. METHOD: We included data of 101 patients with language eloquent brain lesions who underwent preoperative rnTMS examination bihemispherically...
February 2018: Acta Neurochirurgica
C Unterrainer, B Döhler, C Süsal
The reliability of a scientific work depends on the accuracy of the analysis. Scientific publications in the field of kidney transplantation still contain methodical errors that may lead to wrong conclusions and result in severe consequences for the patients. Using the data from the Collaborative Transplant Study, we are presenting in this study six examples of the erroneous usage of statistical methods and show how these mistakes can be avoided.
February 2018: HLA
A Carmona-Bayonas, P Jimenez-Fonseca, A Fernández-Somoano, F Álvarez-Manceñido, E Castañón, A Custodio, F A de la Peña, R M Payo, L P Valiente
Observational studies using registry data make it possible to compile quality information and can surpass clinical trials in some contexts. However, data heterogeneity, analytical complexity, and the diversity of aspects to be taken into account when interpreting results makes it easy for mistakes to be made and calls for mastery of statistical methodology. Some questionable research practices that include poor analytical data management are responsible for the low reproducibility of some results; yet, there is a paucity of information in the literature regarding specific statistical pitfalls of cancer studies...
December 7, 2017: Clinical & Translational Oncology
Thomas R Vetter, Edward J Mascha
Hypothesis testing involves posing both a null hypothesis and an alternative hypothesis. This basic statistical tutorial discusses the appropriate use, including their so-called assumptions, of the common unadjusted bivariate tests for hypothesis testing and thus comparing study sample data for a difference or association. The appropriate choice of a statistical test is predicated on the type of data being analyzed and compared. The unpaired or independent samples t test is used to test the null hypothesis that the 2 population means are equal, thereby accepting the alternative hypothesis that the 2 population means are not equal...
January 2018: Anesthesia and Analgesia
Joshua D Miller, Donald R Lynam
In a recent article published by Fossati and colleagues (2016a, 2016b), the authors compared the empirical profiles derived from correlating measures of narcissism and narcissistic personality disorder (NPD) with a measure of the 25 personality disorder traits included in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; American Psychiatric Association, 2013) to an expert-rated profile of NPD. The initial data, which included some mistakes, were interpreted as indicating comparable performance across all three self-report measures of narcissism and NPD, including two hotly debated measures, the Narcissistic Personality Inventory (NPI) and the Pathological Narcissism Inventory (PNI)...
November 2017: Psychological Assessment
Ephrem A Aboneh, Jamie A Stone, Corey A Lester, Michelle A Chui
OBJECTIVE: Medication errors are common in community pharmacies. Safety culture is considered a factor for medication safety but has not been measured in this setting. The objectives of this study were to describe safety culture measured using the Agency for Healthcare Research and Quality (AHRQ) Community Pharmacy Survey on Patient Safety Culture and to assess predictors of overall patient safety. METHODS: This is a cross-sectional survey of community pharmacists practicing in Wisconsin measuring safety culture...
November 4, 2017: Journal of Patient Safety
Carole S Scherling, Jessica Zakrzewski, Samir Datta, Robert W Levenson, Arthur P Shimamura, Virginia E Sturm, Bruce L Miller, Howard J Rosen
Anosognosia, or lack of awareness of one's deficits, is a core feature of the behavioral variant of frontotemporal dementia (bvFTD). We hypothesized that this deficit has its origins in failed emotional processing of errors. We studied autonomic and facial emotional reactivity to errors in patients with bvFTD (n = 17), Alzheimer's disease (AD, n = 20), and healthy controls (HC, n = 35) during performance of a timed two-alternative-choice button press task. Performance-related behavioral responses to errors were quantified using rates of error correction and post-error slowing of reaction times...
2017: Frontiers in Behavioral Neuroscience
Dorota Kleszczewska, Anna Dzielska, Hanna Nałęcz, Joanna Mazur
BACKGROUND: The wrong subjective assessment of body mass may have consequences for the health, quality of life and proper functioning of adolescents in society. AIM: The purpose of the study is to provide a detailed analysis of the discrepancies between the objective and subjective assessment of body mass by 15-year-old boys and girls in Poland against the background of international statistics and to assess the effect of physical activity on the level and directions of these discrepancies...
2017: Developmental Period Medicine
Jane C Ballantyne
An overreliance on opioids has impacted all types of pain management, making it undoubtedly a root cause of the "epidemic" of prescription opioid abuse in the United States. Yet, an examination of the statistics that led the US Centers for Disease Control and Prevention to declare that prescription opioid abuse had reached epidemic levels shows that the abuse occurrences and deaths are arising outside the hospital or hospice setting, which strongly implicates the outpatient use of opioids to treat chronic pain...
November 2017: Anesthesia and Analgesia
Sean Duffy, John Smith
Duffy, Huttenlocher, Hedges, and Crawford (Psychonomic Bulletin & Review, 17(2), 224-230, 2010) report on experiments where participants estimate the lengths of lines. These studies were designed to test the category adjustment model (CAM), a Bayesian model of judgments. The authors report that their analysis provides evidence consistent with CAM: that there is a bias toward the running mean and not recent stimuli. We reexamine their data. First, we attempt to replicate their analysis, and we obtain different results...
October 18, 2017: Psychonomic Bulletin & Review
I Tuduri Limousin
With this article, we want to emphasize the limits of statistics with little samples, a condition very common in our speciality, focusing in the most usual mistakes in the interpretation of the p-value. Finally, as conclusion, we simulate a clinical study to look what may be a more apropiate boarding.
July 20, 2017: Cirugía Pediátrica: Organo Oficial de la Sociedad Española de Cirugía Pediátrica
Rayana Silva Arceno, Renata Coelho Scharlach
PURPOSE: The present study aimed to evaluate the performance of elderly people in the time-compressed speech test according to the variables ears and order of display, and analyze the types of errors presented by the volunteers. METHODS: This is an observational, descriptive, quantitative, analytical and primary cross-sectional study involving 22 elderly with normal hearing or mild sensorineural hearing loss between the ages of 60 and 80. The elderly were submitted to the time-compressed speech test with compression ratio of 60%, through the electromechanical time compression method...
September 28, 2017: CoDAS
Sixtus Allert, Celeste Flechtner, Peter M Vogt, Christian Herold
Introduction The requested by the "Norddeutsche Schlichtungsstelle ["North German Mediation Centre"] reveal the complications and problems of breast augmentation. The North German Mediation Centre is responsible for ten federal states in Germany (Berlin, Brandenburg, Bremen, Hamburg, Mecklenburg-Western Pomerania, Lower Saxony, Saarland, Saxony-Anhalt, Schleswig-Holstein and Thuringia) and is thus the largest mediation centre in Germany Material and Methods We analysed requests from patients, expert reports ordered by the North German Mediation Centre and the final verdicts of mediations after breast augmentations between 2000 and 2007...
September 2017: Handchirurgie, Mikrochirurgie, Plastische Chirurgie
Chanadda Chinthammit, Michael T Rupp, Edward P Armstrong, Tara Modisett, Rebecca P Snead, Terri L Warholak
BACKGROUND: The importance of creating and sustaining a strong culture of patient safety has been recognized as a critical component of safe medication use. This study aims to assess changes in attitudes toward patient safety culture and frequency of quality-related event (QRE) reporting after guided implementation of a continuous quality improvement (CQI) program in a panel of community pharmacies in the United States (U.S.). METHODS: Twenty-one community pharmacies volunteered to participate in the project and were randomly assigned to intervention or control groups...
2017: Journal of Pharmaceutical Policy and Practice
Siqi Liu, Adam Wright, Milos Hauskrecht
A clinical decision support system (CDSS) and its components can malfunction due to various reasons. Monitoring the system and detecting its malfunctions can help one to avoid any potential mistakes and associated costs. In this paper, we investigate the problem of detecting changes in the CDSS operation, in particular its monitoring and alerting subsystem, by monitoring its rule firing counts. The detection should be performed online, that is whenever a new datum arrives, we want to have a score indicating how likely there is a change in the system...
June 2017: Artificial Intelligence in Medicine: 16th Conference on Artificial Intelligence in Medicine, Aime 2017, Vienna, Austria, June 21-24, 2017, Proceedings
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