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Nevin Manimala Statistics

Evaluation of age-related changes in middle-ear structures by wideband tympanometry

Acta Otolaryngol. 2022 Jun 22:1-4. doi: 10.1080/00016489.2022.2087235. Online ahead of print.

ABSTRACT

BACKGROUND: Presbycusis is bilateral sensorineural hearing loss associated with the progressive degeneration of cochlear and central auditory pathways with aging.

AIMS/OBJECTIVES: We aimed to reveal age-related changes in middle ear function by using wideband tympanometry (WBT).

MATERIALS AND METHODS: Fifty-eight patients diagnosed with presbycusis were compared to 52 audiologically healthy participants. WBT measurement was performed on both ears via wideband click stimulus with a tympanometer device using probe tone frequencies of 226-8000 Hz.

RESULTS: There were no statistically significant differences detected among the resonance frequencies or maximum absorbance ratios measured in both ears between groups (p > .05). The mean absorbance of the right and left ears at 4000 and 8000 Hz was statistically higher in the patient group than in the healthy controls (r = 0.038, 0.030; l = 0.015, 0.012). Moreover, mean compliance values were found to be significantly lower in the patient group than in the control group (r = 0.030 and l = 0.040).

CONCLUSION: The significant differences detected in compliance and absorbance values for high frequencies in presbycusis patients were remarkable. Thus, it has been shown that WBT yields an advantage compared to traditional tympanometry in the diagnosis and treatment of middle ear diseases.

PMID:35732016 | DOI:10.1080/00016489.2022.2087235

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Nevin Manimala Statistics

Nonparametric inference of general while-alive estimands for recurrent events

Biometrics. 2022 Jun 22. doi: 10.1111/biom.13709. Online ahead of print.

ABSTRACT

Measuring the treatment effect on recurrent events like hospitalization in the presence of death has long challenged statisticians and clinicians alike. Traditional inference on the cumulative frequency unjustly penalizes survivorship as longer survivors also tend to experience more adverse events. Expanding a recently suggested idea of “while-alive” event rate, we consider a general class of such estimands that adjust for the length of survival without losing causal interpretation. Given a user-specified loss function that allows for arbitrary weighting, we define as estimand the average loss experienced per unit time alive within a target period and use the ratio of this loss rate to measure the effect size. Scaling the loss rate by the width of the corresponding time window gives us an alternative, and sometimes more photogenic, way of showing the data. To make inference, we construct a nonparametric estimator for the loss rate through the cumulative loss and the restricted mean survival time, and derive its influence function in closed form for variance estimation and testing. As simulations and analysis of real data from a heart failure trial both show, the while-alive approach corrects for the false attenuation of treatment effect due to patients living longer under treatment, with increased statistical power as a result. The proposed methods are implemented in the R-package WA, publicly available from the Comprehensive R Archive Network (CRAN).

PMID:35731993 | DOI:10.1111/biom.13709

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Nevin Manimala Statistics

Joint Final Report of EORTC 26951 and RTOG 9402: Phase III Trials With Procarbazine, Lomustine, and Vincristine Chemotherapy for Anaplastic Oligodendroglial Tumors

J Clin Oncol. 2022 Jun 22:JCO2102543. doi: 10.1200/JCO.21.02543. Online ahead of print.

ABSTRACT

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the basis of the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Anaplastic oligodendroglial tumors (AOTs) are chemotherapy-sensitive brain tumors. We report the final very long-term survival results from European Organization for the Research and Treatment of Cancer 26951 and Radiation Therapy Oncology Group 9402 phase III trials initiated in 1990s, which both studied radiotherapy with/without neo/adjuvant procarbazine, lomustine, and vincristine (PCV) for newly diagnosed anaplastic oligodendroglial tumors. The median follow-up duration in both was 18-19 years. For European Organization for the Research and Treatment of Cancer 26951, median, 14-year, and probable 20-year overall survival rates without versus with PCV were 2.6 years, 13.4%, and 10.1% versus 3.5 years, 25.1%, and 16.8% (N = 368 overall; hazard ratio [HR] 0.78; 95% CI, 0.63 to 0.98; P = .033), with 1p19q codeletion 9.3 years, 26.2%, and 13.6% versus 14.2 years, 51.0%, and 37.1% (n = 80; HR 0.60; 95% CI, 0.35 to 1.03; P = .063), respectively. For Radiation Therapy Oncology Group 9402, analogous results were 4.8 years, 16.5%, and 11.2% versus 4.8 years, 29.1%, and 24.6% (N = 289 overall; HR 0.79; 95% CI, 0.61 to 1.03; P = .08), with codeletion 7.3 years, 25.0%, and 14.9% versus 13.2 years, 46.1%, and 37% (n = 125; HR 0.61; 95% CI, 0.40 to 0.94; P = .02), respectively. With that, the studies show similar long-term survival even without tumor recurrence in a significant proportion of patients after first-line treatment with radiotherapy/PCV.

PMID:35731991 | DOI:10.1200/JCO.21.02543

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Nevin Manimala Statistics

An Investigation of Surgical Nurses’ Professional Values, Ethical Sensitivity and Quality of Care: A Cross-Sectional Study From Northwest Turkey

Eval Health Prof. 2022 Jun 22:1632787221109968. doi: 10.1177/01632787221109968. Online ahead of print.

ABSTRACT

Nurses’ professional values are closely associated with their ethical sensitivity and the quality of nursing care. The aim of this study was to determine surgical nurses’ perceptions of their professional values, ethical sensitivities and quality of care, the relationship between these variables, and the factors influencing these. The sample of this cross-sectional, descriptive and relational study consisted of 231 nurses working in the surgical units of two university hospitals and a training and research hospital. The study revealed a statistically significant negative relationship between the nurses’ professional values scale median score and the Moral Sensitivity Questionnaire median score, and a positive significant relationship between the Nurses’ Professional Values Scale median score and the Care Behaviors Scale median score. Having ethical problems in their professional lives increased the ethical sensitivity of nurses, while having a medical-vocational high school and vocational school of health services degree and participation in training/meetings about professional values and ethics increased the perception of the quality of nursing care. Awareness of professional values is crucial in providing quality nursing care that is in line with ethical principles; therefore, it is recommended that the continuity of surgical nurses’ participation in training/meetings on professional values and ethics be ensured, that they be supported to become members of professional associations, and that supportive working environments be provided to improve the quality of nursing care.

PMID:35731992 | DOI:10.1177/01632787221109968

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Nevin Manimala Statistics

Automated analysis of low-field brain MRI in cerebral malaria

Biometrics. 2022 Jun 22. doi: 10.1111/biom.13708. Online ahead of print.

ABSTRACT

A central challenge of medical imaging studies is to extract biomarkers that characterize disease pathology or outcomes. Modern automated approaches have found tremendous success in high-resolution, high-quality magnetic resonance images (MRI). These methods, however, may not translate to low-resolution images acquired on MRI scanners with lower magnetic field strength. In low-resource settings where low-field scanners are more common and there is a shortage of radiologists to manually interpret MRI scans, it is critical to develop automated methods that can augment or replace manual interpretation, while accommodating reduced image quality. We present a fully automated framework for translating radiological diagnostic criteria into image-based biomarkers, inspired by a project in which children with cerebral malaria were imaged using low-field 0.35 Tesla MRI. We integrate multi-atlas label fusion, which leverages high-resolution images from another sample as prior spatial information, with parametric Gaussian hidden Markov models based on image intensities, to create a robust method for determining ventricular cerebrospinal fluid volume. We also propose normalized image intensity and texture measurements to determine the loss of gray-to-white matter tissue differentiation and sulcal effacement. These integrated biomarkers have excellent classification performance for determining severe brain swelling due to cerebral malaria. This article is protected by copyright. All rights reserved.

PMID:35731973 | DOI:10.1111/biom.13708

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Nevin Manimala Statistics

Nanoscale Visualization of the Electron Conduction Channel in the SiO/Graphite Composite Anode

ACS Appl Mater Interfaces. 2022 Jun 22. doi: 10.1021/acsami.2c01460. Online ahead of print.

ABSTRACT

Conductive atomic force microscopy (C-AFM) is widely used to determine the electronic conductivity of a sample surface with nanoscale spatial resolution. However, the origin of possible artifacts has not been widely researched, hindering the accurate and reliable interpretation of C-AFM imaging results. Herein, artifact-free C-AFM is used to observe the electron conduction channels in Si-based composite anodes. The origin of a typical C-AFM artifact induced by surface morphology is investigated using a relevant statistical method that enables visualization of the contribution of artifacts in each C-AFM image. The artifact is suppressed by polishing the sample surface using a cooling cross-section polisher, which is confirmed by Pearson correlation analysis. The artifact-free C-AFM image was used to compare the current signals (before and after cycling) from two different composite anodes comprising single-walled carbon nanotubes (SWCNTs) and carbon black as conductive additives. The relationship between the electrical degradation and morphological evolution of the active materials depending on the conductive additive is discussed to explain the improved electrical and electrochemical properties of the electrode containing SWCNTs.

PMID:35731963 | DOI:10.1021/acsami.2c01460

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Nevin Manimala Statistics

Cardiac ion channels associated with unexplained stillbirth – An immunohistochemical study

J Perinat Med. 2022 Jun 22. doi: 10.1515/jpm-2022-0227. Online ahead of print.

ABSTRACT

OBJECTIVES: Despite the use of post-mortem investigations, approximately 20% of stillbirths remain unexplained. Cardiac ion channelopathies have been identified as a cause of death in Sudden Infant Death Syndrome (SIDS) and could be associated with unexplained stillbirths. This study aimed to understand if the expression or localisation of cardiac ion channels associated with channelopathies were altered in cases of unexplained stillbirths.

METHODS: A case control study was conducted using formalin-fixed cardiac tissue from 20 cases of unexplained stillbirth and a control group of 20 cases of stillbirths from intrapartum hypoxia. 4 µm tissue sections were stained using haematoxylin and eosin, Masson’s trichrome (MT) and Elastic van Gieson (EVG). Immunohistochemistry (IHC) was performed using antibodies against CACNA1G, KCNJ2, KCNQ1, KCNH2 and KCNE1. The cardiac conduction system in samples stained with MT and EVG could not be identified. Therefore, the levels of immunoperoxidase staining were quantified using QuPath software.

RESULTS: The nuclear-cytoplasmic ratio of sections stained with haematoxylin and eosin was higher for the hypoxia group (hypoxia median 0.13 vs. 0.04 unexplained, p < 0.001). CACNA1G (unexplained median 0.26 vs. hypoxia 0.30, p=0.009) and KCNJ2 (unexplained median 0.35 vs. hypoxia 0.41, p=0.001) had lower staining intensity in the unexplained stillbirth group. There were no statistically significant differences in the staining intensity of KCNQ1, KCNH2 and KCNE1.

CONCLUSIONS: Two ion channels associated with channelopathies demonstrated lower levels of expression in cases of unexplained stillbirth. Further genetic studies using human tissue should be performed to understand the association between channelopathies and otherwise unexplained stillbirths.

PMID:35731905 | DOI:10.1515/jpm-2022-0227

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Nevin Manimala Statistics

An open-access database of infectious disease transmission trees to explore superspreader epidemiology

PLoS Biol. 2022 Jun 22;20(6):e3001685. doi: 10.1371/journal.pbio.3001685. Online ahead of print.

ABSTRACT

Historically, emerging and reemerging infectious diseases have caused large, deadly, and expensive multinational outbreaks. Often outbreak investigations aim to identify who infected whom by reconstructing the outbreak transmission tree, which visualizes transmission between individuals as a network with nodes representing individuals and branches representing transmission from person to person. We compiled a database, called OutbreakTrees, of 382 published, standardized transmission trees consisting of 16 directly transmitted diseases ranging in size from 2 to 286 cases. For each tree and disease, we calculated several key statistics, such as tree size, average number of secondary infections, the dispersion parameter, and the proportion of cases considered superspreaders, and examined how these statistics varied over the course of each outbreak and under different assumptions about the completeness of outbreak investigations. We demonstrated the potential utility of the database through 2 short analyses addressing questions about superspreader epidemiology for a variety of diseases, including Coronavirus Disease 2019 (COVID-19). First, we found that our transmission trees were consistent with theory predicting that intermediate dispersion parameters give rise to the highest proportion of cases causing superspreading events. Additionally, we investigated patterns in how superspreaders are infected. Across trees with more than 1 superspreader, we found preliminary support for the theory that superspreaders generate other superspreaders. In sum, our findings put the role of superspreading in COVID-19 transmission in perspective with that of other diseases and suggest an approach to further research regarding the generation of superspreaders. These data have been made openly available to encourage reuse and further scientific inquiry.

PMID:35731837 | DOI:10.1371/journal.pbio.3001685

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Nevin Manimala Statistics

Prevalence and associated risk factors for mental health problems among patients with polycystic ovary syndrome in Bangladesh: A nationwide cross-Sectional study

PLoS One. 2022 Jun 22;17(6):e0270102. doi: 10.1371/journal.pone.0270102. eCollection 2022.

ABSTRACT

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common female reproductive endocrine problem worldwide. The prevalence of mental disorder is increasing among PCOS patients due to various physical, psychological, and social issues. Here we aimed to evaluate the mental health and associated factors among women suffering from PCOS in Bangladesh.

METHODS: We performed an online cross-sectional survey among 409 participants with PCOS using Google Forms. We used structured questionnaires to collect socio-demographic information and lifestyle-related factors. Also, we applied patient health questionnaire (PHQ-9), generalized anxiety disorder (GAD-7) scale, and UCLA loneliness (UCLA-3) scale for psychometric assessment of the participants. Finally, we applied several statistical tools and performed data interpretations to evaluate the prevalence of mental health disorders and associated factors among patients with PCOS in Bangladesh.

RESULTS: Prevalence of loneliness, generalized anxiety disorder and depressive illness among the women with PCOS were 71%, 88%, and 60%, respectively. Among the mental illness, mild, moderate, and severe cases were 39%, 18%, and 14% for loneliness; 39%, 23% and 26% for generalized anxiety disorder; and 35%, 18%, and 7% for depressive disorder. According to the present findings, obesity, financial condition, physical exercise, mealtime, food habit, daily water consumption, birth control method, and long-term oral contraceptive pills contribute to developing mental health disorders among females with PCOS in Bangladesh.

CONCLUSION: According to present study results, high proportion of women suffering from PCOS experience several mental disorders in Bangladesh. Although several socio-demographic and lifestyle-related factors were found to be associated with the poor mental health of women with PCOS; however, PCOS itself is a condition that favors poor physical and psychological health. Therefore, we recommend proper treatment, public awareness, and a healthy lifestyle to promote the good mental health of women suffering from PCOS.

PMID:35731829 | DOI:10.1371/journal.pone.0270102

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Nevin Manimala Statistics

Tracking the contribution of inductive bias to individualised internal models

PLoS Comput Biol. 2022 Jun 22;18(6):e1010182. doi: 10.1371/journal.pcbi.1010182. Online ahead of print.

ABSTRACT

Internal models capture the regularities of the environment and are central to understanding how humans adapt to environmental statistics. In general, the correct internal model is unknown to observers, instead they rely on an approximate model that is continually adapted throughout learning. However, experimenters assume an ideal observer model, which captures stimulus structure but ignores the diverging hypotheses that humans form during learning. We combine non-parametric Bayesian methods and probabilistic programming to infer rich and dynamic individualised internal models from response times. We demonstrate that the approach is capable of characterizing the discrepancy between the internal model maintained by individuals and the ideal observer model and to track the evolution of the contribution of the ideal observer model to the internal model throughout training. In particular, in an implicit visuomotor sequence learning task the identified discrepancy revealed an inductive bias that was consistent across individuals but varied in strength and persistence.

PMID:35731822 | DOI:10.1371/journal.pcbi.1010182