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Nevin Manimala Statistics

Optimizing spatio-temporal correlation structures for modeling food security in Africa: a simulation-based investigation

BMC Bioinformatics. 2024 Apr 27;25(1):168. doi: 10.1186/s12859-024-05791-w.

ABSTRACT

This study investigates the impact of spatio- temporal correlation using four spatio-temporal models: Spatio-Temporal Poisson Linear Trend Model (SPLTM), Poisson Temporal Model (TMS), Spatio-Temporal Poisson Anova Model (SPAM), and Spatio-Temporal Poisson Separable Model (STSM) concerning food security and nutrition in Africa. Evaluating model goodness of fit using the Watanabe Akaike Information Criterion (WAIC) and assessing bias through root mean square error and mean absolute error values revealed a consistent monotonic pattern. SPLTM consistently demonstrates a propensity for overestimating food security, while TMS exhibits a diverse bias profile, shifting between overestimation and underestimation based on varying correlation settings. SPAM emerges as a beacon of reliability, showcasing minimal bias and WAIC across diverse scenarios, while STSM consistently underestimates food security, particularly in regions marked by low to moderate spatio-temporal correlation. SPAM consistently outperforms other models, making it a top choice for modeling food security and nutrition dynamics in Africa. This research highlights the impact of spatial and temporal correlations on food security and nutrition patterns and provides guidance for model selection and refinement. Researchers are encouraged to meticulously evaluate the biases and goodness of fit characteristics of models, ensuring their alignment with the specific attributes of their data and research goals. This knowledge empowers researchers to select models that offer reliability and consistency, enhancing the applicability of their findings.

PMID:38678218 | DOI:10.1186/s12859-024-05791-w

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Nevin Manimala Statistics

Hospital admissions among patients with Comorbid Substance Use disorders: a secondary analysis of predictors from the NavSTAR Trial

Addict Sci Clin Pract. 2024 Apr 28;19(1):33. doi: 10.1186/s13722-024-00463-9.

ABSTRACT

BACKGROUND: Individuals with substance use disorders (SUDs) frequently use acute hospital services. The Navigation Services to Avoid Rehospitalization (NavSTAR) trial found that a patient navigation intervention for hospitalized patients with comorbid SUDs reduced subsequent inpatient admissions compared to treatment-as-usual (TAU).

METHODS: This secondary analysis extends previous findings from the NavSTAR trial by examining whether selected patient characteristics independently predicted hospital service utilization and moderated the effect of the NavSTAR intervention. Participants were 400 medical/surgical hospital patients with comorbid SUDs. We analyzed 30- and 90-day inpatient readmissions (one or more readmissions) and cumulative incidence of inpatient admissions through 12 months using multivariable logistic and negative binomial regression, respectively.

RESULTS: Consistent with primary findings and controlling for patient factors, NavSTAR participants were less likely than TAU participants to be readmitted within 30 (P = 0.001) and 90 (P = 0.03) days and had fewer total readmissions over 12 months (P = 0.008). Hospitalization in the previous year (P < 0.001) was associated with cumulative readmissions over 12 months, whereas Medicaid insurance (P = 0.03) and index diagnoses of infection (P = 0.001) and injuries, poisonings, or procedural complications (P = 0.004) were associated with fewer readmissions. None of the selected covariates moderated the effect of the NavSTAR intervention.

CONCLUSIONS: Previous findings showed that patient navigation could reduce repeat hospital admissions among patients with comorbid SUDs. Several patient factors were independently associated with readmission. Future research should investigate risk factors for hospital readmission among patients with comorbid SUDs to optimize interventions.

TRIAL REGISTRATION: NIH ClinicalTrials.gov NCT02599818, Registered November 9, 2015 https://classic.

CLINICALTRIALS: gov/ct2/show/NCT02599818 .

PMID:38678216 | DOI:10.1186/s13722-024-00463-9

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Nevin Manimala Statistics

Diagnostic value of LGE and T1 mapping in multiple myeloma patients’heart

BMC Cardiovasc Disord. 2024 Apr 27;24(1):230. doi: 10.1186/s12872-024-03895-y.

ABSTRACT

BACKGROUND: Unidentified heart failure occurs in patients with multiple myeloma when their heart was involved. CMR with late gadolinium enhancement (LGE) and T1 mapping can identify myocardial amyloid infiltrations.

PURPOSE: To explore the role of CMR with late gadolinium enhancement (LGE) and T1 mapping for detection of multiple myeloma patients’heart.

MATERIAL AND METHODS: A total of 16 MM patients with above underwent CMR (3.0-T) with T1 mapping (pre-contrast and post-contrast) and LGE imaging. In addition, 26 patients with non-obstructive hypertrophic cardiomyopathy and 26 healthy volunteers were compared to age- and sex-matched healthy controls without a history of cardiac disease, diabetes mellitus, or normal in CMR. All statistical analyses were performed using the statistical software GraphPad Prism. The measurement data were represented by median (X) and single sample T test was adopted. Enumeration data were represented by examples and Chi-tested was adopted. All tests were two-sided, and P values < 0.05 were considered statistically significant.

RESULTS: In MM group, LVEF was lower than healthy controls and higher than that of non-obstructive hypertrophic cardiomyopathy group, but without statistically significant difference (%: 49.1 ± 17.5 vs. 55.6 ± 10.3, 40.4 ± 15.6, all P > 0.05). Pre-contrast T1 values of MM group were obviously higher than those of healthy controls and non-obstructive hypertrophic cardiomyopathy group (ms:1462.0 ± 71.3vs. 1269.3 ± 42.3, 1324.0 ± 45.1, all P < 0.05). 16 cases (100%) in MM group all had LGE.

CONCLUSION: LGE joint T1 mapping wider clinical use techniques and follow-up the patients’disease severity.

PMID:38678215 | DOI:10.1186/s12872-024-03895-y

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Nevin Manimala Statistics

Problematic meta-analyses: Bayesian and frequentist perspectives on combining randomized controlled trials and non-randomized studies

BMC Med Res Methodol. 2024 Apr 27;24(1):99. doi: 10.1186/s12874-024-02215-4.

ABSTRACT

PURPOSE: In the literature, the propriety of the meta-analytic treatment-effect produced by combining randomized controlled trials (RCT) and non-randomized studies (NRS) is questioned, given the inherent confounding in NRS that may bias the meta-analysis. The current study compared an implicitly principled pooled Bayesian meta-analytic treatment-effect with that of frequentist pooling of RCT and NRS to determine how well each approach handled the NRS bias.

MATERIALS & METHODS: Binary outcome Critical-Care meta-analyses, reflecting the importance of such outcomes in Critical-Care practice, combining RCT and NRS were identified electronically. Bayesian pooled treatment-effect and 95% credible-intervals (BCrI), posterior model probabilities indicating model plausibility and Bayes-factors (BF) were estimated using an informative heavy-tailed heterogeneity prior (half-Cauchy). Preference for pooling of RCT and NRS was indicated for Bayes-factors > 3 or < 0.333 for the converse. All pooled frequentist treatment-effects and 95% confidence intervals (FCI) were re-estimated using the popular DerSimonian-Laird (DSL) random effects model.

RESULTS: Fifty meta-analyses were identified (2009-2021), reporting pooled estimates in 44; 29 were pharmaceutical-therapeutic and 21 were non-pharmaceutical therapeutic. Re-computed pooled DSL FCI excluded the null (OR or RR = 1) in 86% (43/50). In 18 meta-analyses there was an agreement between FCI and BCrI in excluding the null. In 23 meta-analyses where FCI excluded the null, BCrI embraced the null. BF supported a pooled model in 27 meta-analyses and separate models in 4. The highest density of the posterior model probabilities for 0.333 < Bayes factor < 1 was 0.8.

CONCLUSIONS: In the current meta-analytic cohort, an integrated and multifaceted Bayesian approach gave support to including NRS in a pooled-estimate model. Conversely, caution should attend the reporting of naïve frequentist pooled, RCT and NRS, meta-analytic treatment effects.

PMID:38678213 | DOI:10.1186/s12874-024-02215-4

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Nevin Manimala Statistics

Lidocaine effects on neutrophil extracellular trapping and angiogenesis biomarkers in postoperative breast cancer patients with different anesthesia methods: a prospective, randomized trial

BMC Anesthesiol. 2024 Apr 27;24(1):162. doi: 10.1186/s12871-024-02540-7.

ABSTRACT

BACKGROUND: Anesthesia techniques and drug selection may influence tumor recurrence and metastasis. Neutrophil extracellular trapping (NETosis), an immunological process, has been linked to an increased susceptibility to metastasis in individuals with tumors. Furthermore, recurrence may be associated with vascular endothelial growth factor A (VEGF-A), a mediator of angiogenesis. This study investigates the impact of lidocaine (combined with sevoflurane or propofol anesthesia ) during breast cancer surgery inhibits the expression of biomarkers associated with metastasis and recurrence (specifically H3Cit, NE, MPO, MMP-9 and VEGF-A).

METHODS: We randomly assigned 120 women undergoing primary or invasive breast tumor resection to receive one of four anesthetics: sevoflurane (S), sevoflurane plus i.v. lidocaine (SL), propofol (P), and propofol plus i.v. lidocaine (PL). Blood samples were collected before induction and 3 h after the operation. Biomarkers associated with NETosis (citrullinated histone H3 [H3Cit], myeloperoxidase [MPO], and neutrophil elastase [NE]) and angiogenesis were quantified using enzyme-linked immunosorbent assays.

RESULTS: Patient and breast tumor characteristics, along with perioperative management, did not differ between study groups. In intra-group comparisons, S and P groups demonstrated a statistically significant increase in post-operative MPO (S group: 10.39[6.89-17.22] vs. 14.31[8.55-20.87] ng ml-1, P = 0.032; P group: 9.45[6.73-17.37] vs. 14.34[9.87-19.75] ng ml-1, P = 0.035)and NE(S group: 182.70[85.66-285.85] vs. 226.20[91.85-391.65] ng ml-1, P = 0.045; P group: 154.22[97.31-325.30] vs. 308.66[132.36-483.57] ng ml-1, P = 0.037) concentrations compared to pre-operative measurements, whereas SL and PL groups did not display a similar increase. H3Cit, MMP-9, and VEGF-A concentrations were not significantly influenced by the anesthesia techniques and drugs.

CONCLUSIONS: Regardless of the specific technique employed for general anesthesia, there was no increase in the postoperative serum concentrations of MPO and NE after perioperative lidocaine infusion compared to preoperative serum concentrations. This supports the hypothesis that intravenous lidocaine during cancer surgery aimed at achieving a cure may potentially decrease the likelihood of recurrence. Further interpretation and discussion of clinical implications are warranted, emphasizing the significance of these findings in the context of cancer surgery and recurrence prevention.

CLINICAL TRIAL REGISTRATION: ChiCTR2300068563.

PMID:38678209 | DOI:10.1186/s12871-024-02540-7

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Nevin Manimala Statistics

Stability analysis and numerical evaluations of a COVID-19 model with vaccination

BMC Med Res Methodol. 2024 Apr 27;24(1):97. doi: 10.1186/s12874-024-02209-2.

ABSTRACT

A novel (nonlinear) mathematical model for the transmission of Coronavirus 19 (COVID-19) with eight compartments and considering the impact of vaccination is examined in this manuscript. The qualitative behavior of the system such as the boundedness of solutions, the basic reproduction number, and the stability of the equilibrium points is investigated in detail. Some domestic real data collected from the Kerman University of Medical Science (KUMC) is used to estimate the parameters of the proposed model. We predict the dynamical behavior of the system through numerical simulations based on a combined spectral matrix collocation methodology. In this respect, we first linearize the nonlinear system of equations by the method of quasilinearization (QLM). Hence, the shifted version of Chebyshev polynomials of the second kind (SCPSK) is utilized along with the domain-splitting strategy to acquire the solutions of the system over a long time interval. The uniform convergence and upper bound estimation of the SCPSK bases are proved in a rigorous manner. Moreover, the technique of residual error functions is used to testify the accuracy of the QLM-SCPSK method. The presented numerical results justify the robustness and good accuracy of the QLM-SCPSK technique. The achieved numerical orders of convergence indicate that the QLM-SCSK algorithm has exponential rate of convergence. Using the linearization technique in one hand and the domain-splitting strategy on the other hand, enable us to predict the behaviour of similar disease problems with high accuracy and maximum efficiency on an arbitrary domain of interest.

PMID:38678207 | DOI:10.1186/s12874-024-02209-2

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Nevin Manimala Statistics

Early and Late Complications of Mandibulectomy Free Flap Reconstruction: Does the Selective Use of Soft Tissue Only Flaps Reduce Complications?

Ann Otol Rhinol Laryngol. 2024 Apr 27:34894241250177. doi: 10.1177/00034894241250177. Online ahead of print.

ABSTRACT

PURPOSE: This study aims to evaluate the factors most associated with early and late complications following microvascular free tissue transfer (MVFTT) after mandibulectomy.

METHODS: A retrospective review of patients undergoing MVFTT after segmental mandibulectomy from September 2016 to February 2021 was performed across a single academic institution. Surgical variables were collected, including the location of the resultant mandibular defect (anterior vs posterior) and flap type (osseous or non-osseous). The primary outcome variables included postoperative complications (early, <90 days; and late, >90 days) and the patients’ functional status (return to oral intake). Descriptive statistics, chi-square test, Fischer’s exact test, and 2-sample t tests were used to analyze differences among variables.

RESULTS: We analyzed a cohort of 114 consecutive patients with mandibular defects, comprising 57 anterior and 57 posterior defects. Bony free flaps with hardware were used to reconstruct 98% of anterior defects compared to 58% of posterior defects (P < .001). All soft tissue only flaps did not utilize any hardware during the reconstruction. Anterior defects demonstrated more late complications requiring additional surgery (30% vs 9%, P = .04). A secondary analysis of posterior mandibular reconstructions compared soft tissue only flaps and bony free flaps with hardware and showed equivalent rates of early (12% vs 13%, P > .99) and late (9% vs 8%, P > .99) complications requiring additional surgery while demonstrating a similar return to full oral competence (55% vs 46%, P = .52) and recovery of a 100% oral diet (67% vs 54%, P = .53).

CONCLUSION: Osseous free tissue transfer for segmental mandibular defects remains the gold standard in reconstruction. In our patient cohort, anterior mandibular defects are associated with greater late (>90 day) complications requiring additional surgery. Comparable outcomes may be achieved with soft tissue only versus osseous free flap reconstruction of posterior mandibular defects.

PMID:38676442 | DOI:10.1177/00034894241250177

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Nevin Manimala Statistics

Assessing ChatGPT’s Responses to Otolaryngology Patient Questions

Ann Otol Rhinol Laryngol. 2024 Apr 27:34894241249621. doi: 10.1177/00034894241249621. Online ahead of print.

ABSTRACT

OBJECTIVE: This study aims to evaluate ChatGPT’s performance in addressing real-world otolaryngology patient questions, focusing on accuracy, comprehensiveness, and patient safety, to assess its suitability for integration into healthcare.

METHODS: A cross-sectional study was conducted using patient questions from the public online forum Reddit’s r/AskDocs, where medical advice is sought from healthcare professionals. Patient questions were input into ChatGPT (GPT-3.5), and responses were reviewed by 5 board-certified otolaryngologists. The evaluation criteria included difficulty, accuracy, comprehensiveness, and bedside manner/empathy. Statistical analysis explored the relationship between patient question characteristics and ChatGPT response scores. Potentially dangerous responses were also identified.

RESULTS: Patient questions averaged 224.93 words, while ChatGPT responses were longer at 414.93 words. The accuracy scores for ChatGPT responses were 3.76/5, comprehensiveness scores were 3.59/5, and bedside manner/empathy scores were 4.28/5. Longer patient questions did not correlate with higher response ratings. However, longer ChatGPT responses scored higher in bedside manner/empathy. Higher question difficulty correlated with lower comprehensiveness. Five responses were flagged as potentially dangerous.

CONCLUSION: While ChatGPT exhibits promise in addressing otolaryngology patient questions, this study demonstrates its limitations, particularly in accuracy and comprehensiveness. The identification of potentially dangerous responses underscores the need for a cautious approach to AI in medical advice. Responsible integration of AI into healthcare necessitates thorough assessments of model performance and ethical considerations for patient safety.

PMID:38676440 | DOI:10.1177/00034894241249621

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Nevin Manimala Statistics

Deep Learning Model for Grading and Localization of Lumbar Disc Herniation on Magnetic Resonance Imaging

J Magn Reson Imaging. 2024 Apr 27. doi: 10.1002/jmri.29403. Online ahead of print.

ABSTRACT

BACKGROUND: Methods for grading and localization of lumbar disc herniation (LDH) on MRI are complex, time-consuming, and subjective. Utilizing deep learning (DL) models as assistance would mitigate such complexities.

PURPOSE: To develop an interpretable DL model capable of grading and localizing LDH.

STUDY TYPE: Retrospective.

SUBJECTS: 1496 patients (M/F: 783/713) were evaluated, and randomly divided into training (70%), validation (10%), and test (20%) sets.

FIELD STRENGTH/SEQUENCE: 1.5T MRI for axial T2-weighted sequences (spin echo).

ASSESSMENT: The training set was annotated by three spinal surgeons using the Michigan State University classification to train the DL model. The test set was annotated by a spinal surgery expert (as ground truth labels), and two spinal surgeons (comparison with the trained model). An external test set was employed to evaluate the generalizability of the DL model.

STATISTICAL TESTS: Calculated intersection over union (IoU) for detection consistency, utilized Gwet’s AC1 to assess interobserver agreement, and evaluated model performance based on sensitivity and specificity, with statistical significance set at P < 0.05.

RESULTS: The DL model achieved high detection consistency in both the internal test dataset (grading: mean IoU 0.84, recall 99.6%; localization: IoU 0.82, recall 99.5%) and external test dataset (grading: 0.72, 98.0%; localization: 0.71, 97.6%). For internal testing, the DL model (grading: 0.81; localization: 0.76), Rater 1 (0.88; 0.82), and Rater 2 (0.86; 0.83) demonstrated results highly consistent with the ground truth labels. The overall sensitivity of the DL model was 87.0% for grading and 84.0% for localization, while the specificity was 95.5% and 94.4%. For external testing, the DL model showed an appreciable decrease in consistency (grading: 0.69; localization: 0.66), sensitivity (77.2%; 76.7%), and specificity (92.3%; 91.8%).

DATA CONCLUSION: The classification capabilities of the DL model closely resemble those of spinal surgeons. For future improvement, enriching the diversity of cases could enhance the model’s generalization.

TECHNICAL EFFICACY: Stage 2.

PMID:38676436 | DOI:10.1002/jmri.29403

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Nevin Manimala Statistics

Why did peri-pandemic suicide death rates decrease among non-Hispanic white people while increasing among most people of color?

Suicide Life Threat Behav. 2024 Apr 27. doi: 10.1111/sltb.13088. Online ahead of print.

ABSTRACT

INTRODUCTION: While suicides in the United States decreased during the COVID-19 pandemic, statistically significant decreases have been limited to White people throughout a large portion of 2020.

METHODS: This paper outlines possible explanations for racial/ethnic differences in suicidality in the early pandemic phases.

RESULTS: We propose both distal (i.e., tele-mental health usage, internet and technology access, employment protections, and economic security) and proximal (cultural beliefs, coping strategies, clustering, pulling together, and embracing life) factors that may have helped build and foster community and mental wellness. However, this paper argues these factors did not extend, or did not extend as much, to many communities of color.

CONCLUSIONS: We argue that these disparities are due to the myriad effects of discrimination and systemic racism, encapsulated broadly by the minority stress theory, and provide suggestions for relief and research.

PMID:38676429 | DOI:10.1111/sltb.13088