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Nevin Manimala Statistics

Combining adaptive and heat balance models for thermal sensation prediction: A new approach towards a theory and data-driven adaptive thermal heat balance model

Indoor Air. 2022 Mar;32(3):e13018. doi: 10.1111/ina.13018.

ABSTRACT

The adaptive thermal heat balance (ATHB) framework introduced a method to account for the three adaptive principals, namely physiological, behavioral, and psychological adaptation, individually within existing heat balance models. This work presents a more detailed theoretical framework together with a theory-driven empirical determination toward a new formulation of the ATHBPMV . The empirical development followed a rigor statistical process known from machine learning approaches including training, validation, and test phase and makes use of a subset (N = 57 084 records) of the ASHRAE Global Thermal Comfort Database. Results show an increased predictive performance among a wide range of outdoor climates, building types, and cooling strategies of the buildings. Furthermore, individual findings question the common believe that psychological adaptation is highest in naturally ventilated buildings. The framework offers further opportunities to include a variety of context-related variables as well as personal characteristics into thermal prediction models, while keeping mathematical equations limited and enabling further advancements related to the understanding of influences on thermal perception.

PMID:35347785 | DOI:10.1111/ina.13018

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Nevin Manimala Statistics

Exploring wait time variations in a prostate cancer patient pathway-A qualitative study

Int J Health Plann Manage. 2022 Mar 28. doi: 10.1002/hpm.3454. Online ahead of print.

ABSTRACT

Norwegian health authorities emphasise that all citizens should have equal access to healthcare and implement cancer patient pathways (CPPs) to ensure medical care for all patients within the same time frame and to avoid unwanted variation. Statistics regarding prostate cancer indicate longer wait times for patients from a local hospital compared to patients from a university hospital. This study describes which health system-related factors influence variations in wait times. Eighteen healthcare workers participated in qualitative individual interviews conducted using a semi-structured interview guide. Transcripts were analysed by systematic text condensation, which is a cross-case method for the thematic analysis of qualitative data. The analysis unveiled four categories describing possible health system-related factors causing variation in times spent on diagnostics for patients in the local hospital and in university hospital, respectively: (a) capacity and competence, (b) logistics and efficiency, (c) need for highly specialised investigations, and (d) need for extra consultations. Centralisation of surgical treatment necessitated the transfer of patients, with extra steps indicated in the CPP for patients transferring from the local hospital to the university hospital for surgery. The local hospital seemed to lack capacity more frequently than the university hospital. Possible factors explaining variations in wait time between the two hospitals concern both internal conditions at the hospitals in organising CPPs and the implications of transferring patients between hospitals. Differences in hospitals’ capacity can cause variations in wait time. The extra steps involved in transferring patients between hospitals can lead to additional time spent in CPP.

PMID:35347768 | DOI:10.1002/hpm.3454

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Nevin Manimala Statistics

Unpacking cesarean in rural Bangladesh: Who, what, when, and where

Birth. 2022 Mar 28. doi: 10.1111/birt.12636. Online ahead of print.

ABSTRACT

BACKGROUND: Bangladesh has experienced an alarming increase in birth through cesarean over the last decade. In this article, we examine rural Bangladeshi women’s reporting of why they underwent cesarean, who proposed the cesarean, and when in the process, the decision for a surgical birth was made.

METHODS: We conducted a cross-sectional household survey of 2299 women in Kushtia district. Of these, 1233 who gave birth through cesarean completed a supplemental questionnaire. Descriptive statistics were used to report cesarean rates, which were disaggregated by sociodemographic characteristics and by antenatal care contacts with health services. We analyzed women’s reported reasons for having a cesarean, when the decision was taken, and who proposed the intervention.

FINDINGS: Over half (54%) of women gave birth through cesarean. The proportion of cesareans was significantly higher among women with higher educational attainment, higher socioeconomic status, and increased antenatal care during pregnancy, particularly if this care was sought in private facilities (P < .05). Women reported that health service providers primarily proposed the cesarean (73%), followed by family members (21%) and finally, the birthing person themselves (6%). With respect to the reasons for cesarean, 34% of women reported nonmedical reasons (convenience and avoidance of labor pain), and 44% mentioned only medical reasons. Over half of the women reported that the decision to undergo a cesarean was made on the day of birth.

CONCLUSIONS: Women in rural Bangladesh often report avoidable reasons for cesarean. Better regulation of cesarean services in both public and private health services, as well as improved counseling of women with respect to cesarean indications and their consequences, is recommended.

PMID:35347769 | DOI:10.1111/birt.12636

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Nevin Manimala Statistics

Comparative accuracy of two veterinary-calibrated point-of-care glucometres for measurement of blood glucose concentration in dogs

J Small Anim Pract. 2022 Mar 28. doi: 10.1111/jsap.13491. Online ahead of print.

ABSTRACT

OBJECTIVES: To investigate and compare the accuracy of two veterinary portable blood glucose metres (AccuTell; AccubioTech; and AlphaTrak2; Abbott Laboratories).

MATERIALS AND METHODS: One hundred twenty venous blood samples were obtained for immediate whole blood glucose concentration measurement using two portable blood glucose metres designed for use in dogs. Plasma glucose concentration was measured by a laboratory analyser using a hexokinase reaction method. Packed cell volume was measured for each sample. Linear regression analysis was performed and Bland-Altman plots constructed with International Standards Organisation 15197:2013 standards applied to assess relationship and agreement between results of portable blood glucose metres and laboratory analyser methods, respectively. Clarke’s error grid analysis was used to assess clinical accuracy and usefulness.

RESULTS: The AccuTell and the AlphaTrak2 had mean differences of -0.69 ± 0.70 mmol/L (bias ±sd) and -1.09 ± 1.22 mmol/L (bias ± sd) with the reference analyser, respectively. Eighty-eight of 120 (73.3%) samples for the AccuTell, and 73 of 120 (60.8%) samples for the AlphaTrak2 were plotted in the zone of the error grid analysis that indicated less clinical risk of misdiagnosis of glucose status. Neither device fulfilled the International Standards Organisation 15197:2013 standards for system accuracy. A statistically significant effect of packed cell volume was identified on the difference between blood glucose concentration obtained by the AlphaTrak2 and the hexokinase reaction method, but not for the AccuTell.

CLINICAL SIGNIFICANCE: Both devices do not meet International Standards Organisation 15197:2013 standards. Users should expect 95% of the samples measured with the AccuTell to be between -0.7 and +2.1 mmol/L higher than actual values, and 95% of the samples measured with the AlphaTrak2 to be between -1.3 and +3.5 mmol/L higher than actual values.

PMID:35347740 | DOI:10.1111/jsap.13491

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Nevin Manimala Statistics

Covid-19 First Wave Impact National Survey for HIV Clinicians by Public Health England (PHE), the British HIV Association (BHIVA) and the Children’s HIV Association (CHIVA)

HIV Med. 2022 Mar 28. doi: 10.1111/hiv.13307. Online ahead of print.

ABSTRACT

INTRODUCTION: This short report describes the results of a survey that was developed by Public Health England (PHE), the British HIV Association (BHIVA) and the Children’s HIV Association (CHIVA) and circulated to all UK national health service HIV providers in the UK following the first wave of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; coronavirus disease 2019 [COVID-19]) pandemic to assess the impact of the pandemic on HIV clinics.

METHODS: The survey was created by BHIVA/CHIVA and PHE and was piloted prior to circulation to all HIV clinics within the UK on 3 July 2020. The survey questions were designed to assess the impact of the first wave of COVID-19 on HIV clinics and lead/senior HIV clinicians. Clinicians’ responses were collected between 3 July 2020 and 17 September 2020. The survey responses were collated, and non-statistical analysis was performed.

RESULTS: The results of the survey confirmed that services had undergone substantial changes, including a shift from face-to-face consults to predominantly virtual consultations. Some clinicians’ responses suggested that the first wave had many negative effects on people living with HIV, including their ability to access mental health services.

CONCLUSION: The first wave of COVID-19 caused significant changes to HIV services within the UK. There was a shift toward the use of technology in healthcare, and results from subsequent clinician surveys carried out since the first wave of COVID-19 will reflect the ongoing transformation of care towards a more virtual service.

PMID:35345056 | DOI:10.1111/hiv.13307

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Nevin Manimala Statistics

Return-to-sports after minimally invasive stabilization of intra-articular calcaneal fractures

Sportverletz Sportschaden. 2022 Mar 28. doi: 10.1055/a-1688-3720. Online ahead of print.

ABSTRACT

BACKGROUND: Evaluation of different factors in patient quality of life after minimally invasive stabilization of intra-articular calcaneal fractures, including the return-to-sports rate.

PATIENTS AND METHODS: Patients with minimally invasive stabilization of intra-articular calcaneal fractures were collected from the database of a Level I trauma center and evaluated in a retrospective and explorative way. The clinical and radiological examination have been done immediately after the operation, after 2 and 6 weeks postoperative and after a minimum follow-up of 2 years. Clinical and radiological examination was performed by applying the American Orthopedic Foot and Ankle Society hindfoot scale score (AOFAS), 36-item Short Form Health Survey (SF-36), the Tegner Activity Scale, the Foot and Ankle Outcome Score (FAOS) and with a questionnaire about pre- and postoperative engagement in sport and recreational activities.

RESULTS: Fourty-nine patients with an isolated uni-lateral fracture of the calcaneus who fulfilled all inclusion criteria were assessed. Fourty-two of them were male and 24 were under the age of 50 years. No statistically significant differences were noted between Sanders I/II and Sanders III/IV in terms of SF-36, AOFAS, FAOS or Tegner-scale. A less satisfying result was noticed in Sanders III/IV patients. General health, pain in FAOS, physical functioning and pain in SF-36 were strongly dependent on Tegner score values. Twenty-nine percent of our study population changed sport activities after injury, whereas 22 percent stopped all kinds of sports. Consequently, our overall return-to-sport rate was 78 percent.

CONCLUSION: Clinical results including different scores and quality of life parameters in our study population were satisfying. About 80 percent of patients could return to sports, but there are still many patients that were not able to perform sports and physical activities on the same level as before.

PMID:35345053 | DOI:10.1055/a-1688-3720

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Nevin Manimala Statistics

Histologic and Clinical Correlates of Multiplex Stool Polymerase Chain Reaction Assay Results

Arch Pathol Lab Med. 2022 Mar 28. doi: 10.5858/arpa.2021-0329-OA. Online ahead of print.

ABSTRACT

CONTEXT.—: Multiplex stool polymerase chain reaction tests (SPTs) simultaneously test for many enteric pathogens. However, the clinical significance of a positive result, particularly in the context of chronic gastrointestinal disease, remains controversial.

OBJECTIVE.—: To determine whether SPT results correlate with findings on colon biopsies obtained within a week of SPT or with clinical features.

DESIGN.—: We reviewed 261 colon biopsies during a 15-month period that were obtained within a week of SPT, along with available clinical information, from patients with and without chronic idiopathic inflammatory bowel disease (CIIBD). Statistical analysis was used to test associations between SPT result, histologic features, and clinical variables.

RESULTS.—: The most commonly detected pathogens were Clostridium difficile, enteropathogenic Escherichia coli, and norovirus. The presence of underlying CIIBD did not correlate with a positive SPT result or with a specific pathogen. Positive SPT result was significantly associated with neutrophilic activity, pseudomembranes, and increased intraepithelial lymphocytes. In addition, the presence of C difficile on SPT was significantly associated with pseudomembranes and neutrophilic activity. There were no other statistically significant relationships between SPT result and any other histologic abnormality. Only about half of SPT positive results were acted on clinically, and most patients with CIIBD were managed as having a presumed IBD flare.

CONCLUSIONS.—: SPTs have many advantages; however, interpretation of results, particularly in the background of chronic gastrointestinal disease, remains a challenge. Therapeutic decisions influenced by a positive SPT result should integrate biopsy findings, clinical data, and other laboratory testing to avoid inappropriate treatment.

PMID:35344996 | DOI:10.5858/arpa.2021-0329-OA

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Nevin Manimala Statistics

eSPA+: Scalable Entropy-Optimal Machine Learning Classification for Small Data Problems

Neural Comput. 2022 Mar 23:1-36. doi: 10.1162/neco_a_01490. Online ahead of print.

ABSTRACT

Classification problems in the small data regime (with small data statistic T and relatively large feature space dimension D) impose challenges for the common machine learning (ML) and deep learning (DL) tools. The standard learning methods from these areas tend to show a lack of robustness when applied to data sets with significantly fewer data points than dimensions and quickly reach the overfitting bound, thus leading to poor performance beyond the training set. To tackle this issue, we propose eSPA+, a significant extension of the recently formulated entropy-optimal scalable probabilistic approximation algorithm (eSPA). Specifically, we propose to change the order of the optimization steps and replace the most computationally expensive subproblem of eSPA with its closed-form solution. We prove that with these two enhancements, eSPA+ moves from the polynomial to the linear class of complexity scaling algorithms. On several small data learning benchmarks, we show that the eSPA+ algorithm achieves a many-fold speed-up with respect to eSPA and even better performance results when compared to a wide array of ML and DL tools. In particular, we benchmark eSPA+ against the standard eSPA and the main classes of common learning algorithms in the small data regime: various forms of support vector machines, random forests, and long short-term memory algorithms. In all the considered applications, the common learning methods and eSPA are markedly outperformed by eSPA+, which achieves significantly higher prediction accuracy with an orders-of-magnitude lower computational cost.

PMID:35344997 | DOI:10.1162/neco_a_01490

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Nevin Manimala Statistics

On Neural Network Kernels and the Storage Capacity Problem

Neural Comput. 2022 Mar 23:1-7. doi: 10.1162/neco_a_01494. Online ahead of print.

ABSTRACT

In this short note, we reify the connection between work on the storage capacity problem in wide two-layer treelike neural networks and the rapidly growing body of literature on kernel limits of wide neural networks. Concretely, we observe that the “effective order parameter” studied in the statistical mechanics literature is exactly equivalent to the infinite-width neural network gaussian process kernel. This correspondence connects the expressivity and trainability of wide two-layer neural networks.

PMID:35344992 | DOI:10.1162/neco_a_01494

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Nevin Manimala Statistics

Direct Discriminative Decoder Models for Analysis of High-Dimensional Dynamical Neural Data

Neural Comput. 2022 Mar 23:1-36. doi: 10.1162/neco_a_01491. Online ahead of print.

ABSTRACT

With the accelerated development of neural recording technology over the past few decades, research in integrative neuroscience has become increasingly reliant on data analysis methods that are scalable to high-dimensional recordings and computationally tractable. Latent process models have shown promising results in estimating the dynamics of cognitive processes using individual models for each neuron’s receptive field. However, scaling these models to work on high-dimensional neural recordings remains challenging. Not only is it impractical to build receptive field models for individual neurons of a large neural population, but most neural data analyses based on individual receptive field models discard the local history of neural activity, which has been shown to be critical in the accurate inference of the underlying cognitive processes. Here, we propose a novel, scalable latent process model that can directly estimate cognitive process dynamics without requiring precise receptive field models of individual neurons or brain nodes. We call this the direct discriminative decoder (DDD) model. The DDD model consists of (1) a discriminative process that characterizes the conditional distribution of the signal to be estimated, or state, as a function of both the current neural activity and its local history, and (2) a state transition model that characterizes the evolution of the state over a longer time period. While this modeling framework inherits advantages of existing latent process modeling methods, its computational cost is tractable. More important, the solution can incorporate any information from the history of neural activity at any timescale in computing the estimate of the state process. There are many choices in building the discriminative process, including deep neural networks or gaussian processes, which adds to the flexibility of the framework. We argue that these attributes of the proposed methodology, along with its applicability to different modalities of neural data, make it a powerful tool for high-dimensional neural data analysis. We also introduce an extension of these methods, called the discriminative-generative decoder (DGD). The DGD includes both discriminative and generative processes in characterizing observed data. As a result, we can combine physiological correlates like behavior with neural data to better estimate underlying cognitive processes. We illustrate the methods, including steps for inference and model identification, and demonstrate applications to multiple data analysis problems with high-dimensional neural recordings. The modeling results demonstrate the computational and modeling advantages of the DDD and DGD methods.

PMID:35344988 | DOI:10.1162/neco_a_01491