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Nevin Manimala Statistics

Finite Mixtures of Multivariate t $$ t $$ Linear Mixed-Effects Models for Censored Longitudinal Data With Concomitant Covariates

Stat Med. 2026 Jan;45(1-2):e70392. doi: 10.1002/sim.70392.

ABSTRACT

Clustering longitudinal biomarkers in clinical trials uncovers associations between clinical outcomes, disease progression, and treatment effects. Finite mixtures of multivariate t $$ t $$ linear mixed-effects (FM-MtLME) models have proven effective for modeling and clustering multiple longitudinal trajectories that exhibit grouped patterns with strong within-group similarity. Motivated by an AIDS study with plasma viral loads measured under assay-specific detection limits, this article extends the FM-MtLME model to account for censored outcomes. The proposed model is called the FM-MtLME with censoring (FM-MtLMEC). To allow covariate-dependent mixing proportions, we further extend it with a logistic link, resulting in the EFM-MtLMEC model. Two efficient EM-based algorithms are developed for parameter estimation of both FM-MtLMEC and EFM-MtLMEC models. The utility of our methods is demonstrated through comprehensive analyses of the AIDS data and simulation studies.

PMID:41569638 | DOI:10.1002/sim.70392

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Nevin Manimala Statistics

Interactive Digital Visualization Counseling for Lifestyle Change in Patients at Risk of Cardiovascular Diseases: Randomized Controlled Trial

JMIR Public Health Surveill. 2026 Jan 22;12:e83488. doi: 10.2196/83488.

ABSTRACT

BACKGROUND: Cardiovascular disease (CVD) remains the leading cause of death. Primary prevention relies heavily on health risk assessments and lifestyle changes, which can reduce long-term risk and mortality. Digital health offers an accessible and cost-effective approach to support prevention, enabling data sharing and visualization of key indicators such as blood pressure and glucose fluctuations. These visual insights may help patients better understand the effects of lifestyle changes and enhance communication with health care providers.

OBJECTIVE: This research aims to evaluate whether the use of CVD risk visualization (Petal-X) and continuous glucose monitoring (CGM), alone or in combination, is associated with lifestyle changes and the perception of person-centered care (PCC) among patients at increased risk of CVD.

METHODS: We conducted a 4-arm, single-blind, 2×2 factorial randomized controlled feasibility trial in primary care. A total of 119 participants were enrolled, of whom 101 completed the 6-month follow-up. Participants were randomized to 1 of 4 arms: (1) Petal-X CVD risk visualization+CGM; (2) CGM only; (3) Petal-X only; or (4) standard care with routine lifestyle counseling and no digital tools. CGM was used for 10 days in the CGM arms. Since this was a feasibility trial, no formal sample size calculation was performed. Primary outcomes are healthy lifestyle (Health Lifestyle and Personal Control Questionnaire [HLPCQ]) and perception of PCC (Person-Centered Practice Inventory-Service User [PCPI-SU]), and secondary outcomes (Systematic Coronary Risk Evaluation 2 [SCORE2], anthropometrics, and biological age) were assessed at baseline and 6 months. Descriptive statistics and Kruskal-Wallis tests (K independent samples) were used for analyses.

RESULTS: At baseline, mean SCORE2 values ranged from 3.84 (SD 2.08) in intervention group 3 to 4.87 (SD 2.61) in intervention group 1, with the control group having a mean value of 4.53 (SD 3.63). Regarding the assessment of a healthy lifestyle, the domain of daily routine had the highest baseline scores across all groups (eg, mean 19.24, SD 5.87 in intervention group 1), and these scores improved by the final evaluation, although there were no statistically significant differences (P=.42) in changes between the groups. The perception of PCC was rated highest across all groups in the domain of shared decision-making, with no statistically significant differences (P=.26) between the groups. Results indicated improvements in healthy lifestyle habits, but the impact of interventions on perceived changes remained insignificant.

CONCLUSIONS: Healthy lifestyle and perceived PCC scores improved, although no statistically significant between-group differences were found. Risk visualization appears to be a key tool for increasing CVD awareness and strengthening patient involvement in care planning. Longer interventions with larger samples are needed to clarify these effects and optimize digital tools for lifestyle change.

PMID:41569629 | DOI:10.2196/83488

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Nevin Manimala Statistics

Bayesian Clustering Factor Models

Stat Med. 2026 Jan;45(1-2):e70350. doi: 10.1002/sim.70350.

ABSTRACT

We present a novel framework for concomitant dimension reduction and clustering. This framework is based on a novel class of Bayesian clustering factor models. These models assume a factor model structure where the vectors of common factors follow a mixture of Gaussian distributions. We develop a Gibbs sampler to explore the posterior distribution and propose an information criterion to select the number of clusters and the number of factors. Simulation studies show that our inferential approach appropriately quantifies uncertainty. In addition, when compared to two previously published competitor methods, our information criterion has favorable performance in terms of correct selection of number of clusters and number of factors. Finally, we illustrate the capabilities of our framework with an application to data on recovery from opioid use disorder where clustering of individuals may facilitate personalized health care.

PMID:41569628 | DOI:10.1002/sim.70350

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Nevin Manimala Statistics

Multi-Model Ensembles in Infectious Disease and Public Health: Methods, Interpretation, and Implementation in R

Stat Med. 2026 Jan;45(1-2):e70333. doi: 10.1002/sim.70333.

ABSTRACT

Combining predictions from multiple models into an ensemble is a widely used practice across many fields with demonstrated performance benefits. Popularized through domains such as weather forecasting and climate modeling, multi-model ensembles are becoming increasingly common in public health and biological applications. For example, multi-model outbreak forecasting provides more accurate and reliable information about the timing and burden of infectious disease outbreaks to public health officials and medical practitioners. Yet, understanding and interpreting multi-model ensemble results can be difficult, as there are a diversity of methods proposed in the literature with no clear consensus on which is best. Moreover, a lack of standard, easy-to-use software implementations impedes the generation of multi-model ensembles in practice. To address these challenges, we provide an introduction to the statistical foundations of applied probabilistic forecasting, including the role of multi-model ensembles. We introduce the hubEnsembles package, a flexible framework for ensembling various types of predictions using a range of methods. Finally, we present a tutorial and case-study of ensemble methods using the hubEnsembles package on a subset of real, publicly available data from the FluSight Forecast Hub.

PMID:41569627 | DOI:10.1002/sim.70333

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Nevin Manimala Statistics

A DNN-Based Weighted Partial Likelihood for Partially Linear Subdistribution Hazard Model

Stat Med. 2026 Jan;45(1-2):e70397. doi: 10.1002/sim.70397.

ABSTRACT

Deep learning has excelled in the field of statistical learning. In the field of survival analysis, some studies have combined deep learning methods with partially linear structures to propose deep partially linear structures. We extend it to the field of competing risks and propose the deep partially linear subdistribution hazard model (DPLSHM). To evaluate the predictive performance of the model, we further develop a time-dependent AUC method specifically tailored for competing risks data and provide an estimator for AUC. Theoretical results for the proposed model demonstrate the asymptotic normality of the parameter component at a rate of n $$ sqrt{n} $$ and provide the convergence rate of the nonparametric component, which achieves the minimal limit convergence rate (multiplicative logarithmic factors). The theory of consistency and rate of convergence of AUC-related estimates is also developed, while we prove that the regression component of DPLSHM maximizes theoretical AUC asymptotically. Subsequently, the paper validates the excellent performance of DPLSHM in estimation and prediction through numerical simulations and real-world datasets.

PMID:41569618 | DOI:10.1002/sim.70397

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Nevin Manimala Statistics

Nonparametric Bayesian Adjustment of Unmeasured Confounders in Cox Proportional Hazards Models

Stat Med. 2026 Jan;45(1-2):e70360. doi: 10.1002/sim.70360.

ABSTRACT

Unmeasured confounders pose a major challenge in accurately estimating causal effects in observational studies. To address this issue when estimating hazard ratios (HRs) using Cox proportional hazards models, several methods, including instrumental variables (IVs) approaches, have been proposed. However, these methods often face limitations, such as weak IV problems and restrictive assumptions regarding unmeasured confounder distributions. In this study, we introduce a novel nonparametric Bayesian procedure that provides accurate HR estimates while addressing these limitations. A key assumption of our approach is that unmeasured confounders exhibit a cluster structure. Under this assumption, we integrate two remarkable Bayesian techniques, the Dirichlet process mixture (DPM) and general Bayes (GB), to simultaneously (1) detect latent clusters based on the likelihood of exposure and outcome variables and (2) estimate HRs using the likelihood constructed within each cluster. Notably, leveraging DPM, our procedure eliminates the need for IVs by identifying unmeasured confounders under an alternative condition. Additionally, GB techniques remove the need for explicit modeling of the baseline hazard function, distinguishing our procedure from traditional Bayesian approaches. Simulation experiments demonstrate that the proposed Bayesian procedure outperforms existing methods in some performance metrics. Moreover, it achieves statistical efficiency comparable to the efficient estimator while accurately identifying cluster structures. These features highlight its ability to overcome challenges associated with traditional IV approaches for time-to-event data.

PMID:41569616 | DOI:10.1002/sim.70360

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Nevin Manimala Statistics

Promotion of Emergency Medical Services: A National Analysis of Clinician Willingness to Recommend the Profession

Prehosp Emerg Care. 2026 Jan 22:1-12. doi: 10.1080/10903127.2026.2619038. Online ahead of print.

ABSTRACT

OBJECTIVES: Emergency medical services (EMS) workforce challenges impact prehospital care provision in many United States communities. One potential strategy to address this challenge is for clinicians to actively promote the EMS profession. However, there is limited data regarding the likelihood of EMS clinicians recommending others to join the EMS profession. We aimed to describe professional promotion among EMS clinicians and factors that impact their likelihood of recommending.

METHODS: We performed a cross-sectional analysis of nationally certified civilian EMS clinicians (ages 18-85) recertifying between 10/2023 and 04/2024. Applicants completed a voluntary survey regarding EMS professional promotion measured using the Net Promoter Score®. This validated tool measures the likelihood of recommending a field to others (classified as promoters, passives, or detractors). Surveys were merged with demographic and workplace characteristics from the National EMS Certification database. We calculated descriptive statistics (n, %) and (median, interquartile range [IQR]) and performed multivariable logistic regression (odds ratio, 95% confidence interval) to identify factors associated with likelihood of promoting EMS by clinicians, including age, sex, race, certification, education, years experience, agency and service type, and self-reported burnout and job satisfaction as covariates.

RESULTS: We included 33,335 clinicians for analysis (response rate = 28.8%); respondents reflected the nationally certified EMS population (male [74.2%], non-Hispanic White [86.1%], median age 36 [IQR: 29, 49], patient care [90.8%]). Promotion score distribution balanced between promoters (33.8%), passives (33.1%), and detractors (33.1%), yielding a NPS = 0.7 (possible range: -100 to +100), indicating near-zero net promotion. Odds of promoting EMS across agency types were lower than fire agencies (p < 0.05). Odds of promotion were also lower for higher education levels (associate [0.90,0.82-0.98], bachelor’s [0.80,0.73-0.87]; [referent: ≤high school/General Educational Development]) and more years experience (3-7 [0.86,0.81-0.93], 8-15 [0.76,0.70-0.82], >15 [0.83,0.75-0.91]; [referent: 0-3]). Clinicians reporting burnout had significantly lower odds of promoting EMS (0.31,0.29-0.33), while clinicians with high levels of job satisfaction had increased odds of promoting EMS (6.27,5.08-7.74).

CONCLUSIONS: Demographic and workplace characteristics are significantly associated with the likelihood of EMS clinicians promoting the profession. The observed associations with satisfaction and burnout suggest areas that may warrant further investigation regarding their relationship to professional promotion and broader workforce dynamics.

PMID:41569613 | DOI:10.1080/10903127.2026.2619038

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Nevin Manimala Statistics

Maximal Local Privacy Loss-A New Method for Privacy Evaluation of Synthetic Datasets

Stat Med. 2026 Jan;45(1-2):e70376. doi: 10.1002/sim.70376.

ABSTRACT

Synthetic patient data has the potential to advance research in the medical field by providing privacy-preserving access to data resembling sensitive personal data. Assessing the level of privacy offered is essential to ensure privacy compliance, but it is challenging in practice. Many common methods either fail to capture central aspects of privacy or result in excessive caution based on unrealistic worst-case scenarios. We present a new approach to evaluating the privacy of synthetic datasets from known probability distributions based on the maximal local privacy loss. The strategy is based on measuring individual contributions to the likelihood of generating a specific synthetic dataset, to detect possibilities of reconstructing records in the original data. To demonstrate the method, we generate synthetic time-to-event data based on pancreatic and colon cancer data from the Cancer Registry of Norway using sequential regressions including a flexible parametric survival model. This illustrates the method’s ability to measure information leakage at an individual level, which can be used to ensure acceptable privacy risks for every patient in the data.

PMID:41569604 | DOI:10.1002/sim.70376

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Nevin Manimala Statistics

People With Early Psychosis Exhibit Distinct Profiles in Neurocognition, Social Cognition and Cognitive Biases: An Exploratory Cluster Analysis

Clin Psychol Psychother. 2026 Jan-Feb;33(1):e70226. doi: 10.1002/cpp.70226.

ABSTRACT

Research into the differences across cognitive domains has been conducted to characterize the various presentations of schizophrenia-spectrum disorders. We aimed to identify distinct combined cognitive profiles with clinical relevance in patients with early psychosis (EP) by integrating neurocognition, social cognition and cognitive biases (CBs). Seventy-five outpatients attending an EP programme were assessed on neuropsychological performance, Theory of Mind (ToM), facial emotion recognition (FER), jumping to conclusions (JTC) bias and self-reported CBs through standardized tools. A two-step cluster analysis was performed to identify latent profiles. The optimal number of clusters was determined based on the Bayesian information criterion. Symptom dimensions, depression, global functioning, antipsychotic use, duration of untreated psychosis (DUP) and sociodemographic variables were compared across the resulting clusters. Two distinct profiles were identified. The first cluster (53.3%) was characterized by significant impairments in neurocognition, ToM and FER, as well as greater JTC and self-reported CBs. The second cluster (46.7%) was defined by relatively preserved performance across cognitive domains. Furthermore, the impaired cluster showed more severe positive, negative and disorganized symptoms, poorer functioning, lower premorbid intelligence and increased use of antipsychotics. No significant differences were found for depression, DUP or sociodemographic variables. Concluding, cognitive clustering revealed a clinically impaired subgroup of patients with more severe psychotic symptoms and poorer functioning. Our results may contribute to a better understanding of the distinct cognitive profiles of patients with EP. These findings may be relevant because several interventions targeting different cognitive domains have been shown to improve clinical and functional outcomes in EP.

PMID:41569600 | DOI:10.1002/cpp.70226

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Nevin Manimala Statistics

Proportion, Morbidity, and Mortality of Acute Invasive Fungal Rhinosinusitis in Immunocompromised Populations: A Systematic Review and Meta-analysis

JAMA Otolaryngol Head Neck Surg. 2026 Jan 22. doi: 10.1001/jamaoto.2025.5077. Online ahead of print.

ABSTRACT

IMPORTANCE: Acute invasive fungal rhinosinusitis (AIFRS) is a rapidly progressive and potentially life-threatening infection that predominantly affects immunocompromised patients. Recent advances in diagnostic imaging, antifungal therapy, and surgical techniques may have altered its incidence, morbidity, and mortality.

OBJECTIVE: To evaluate temporal trends in the pooled proportion, morbidity, and mortality of AIFRS in immunocompromised patients and assess the association of diagnostic and therapeutic advances.

DATA SOURCES: Systematic searches of Ovid MEDLINE, Ovid Embase, PubMed, Scopus, Web of Science, Cochrane, and Google Scholar from 1977 through October 20, 2025, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

STUDY SELECTION: Prospective, retrospective, and cross-sectional studies and case series reporting pooled proportion, morbidity, or mortality of AIFRS in immunocompromised patients were included. Non-English articles, reviews, editorials, and studies with fewer than 10 patients were excluded.

DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted data using standardized templates; disagreements were resolved by consensus. Risk of bias was assessed using the Newcastle-Ottawa Scale and Murad tool for case series. Random-effects meta-analysis generated pooled proportion, morbidity, and mortality rates with 95% CIs. Heterogeneity was quantified using I2 statistics. Meta-regression and sensitivity analyses evaluated temporal trends and study-level effects.

MAIN OUTCOMES AND MEASURES: Pooled proportion, morbidity, and mortality rates of AIFRS stratified by publication period (1983-2012 vs 2013-2025).

RESULTS: A total of 205 studies comprising 48 437 immunocompromised patients (median [range] age, 49.4 [5.2-68.8] years), including 10 311 (21.3%) with AIFRS, were analyzed. The pooled proportion was 11.8% (95% CI, 7.9%-17.2%), rising to 16.6% (95% CI, 8.7%-29.2%) in studies from 2013 to 2025. Overall mortality was 31.2% (95% CI, 28.3%-34.3%), declining from 41.9% (95% CI, 35.0%-49.1%) before 2013 to 28.2% (95% CI, 25.1%-31.4%) after 2013. Morbidity was 37.0% (95% CI, 32.9%-41.4%), with similar rates across periods (39.3% before 2013 vs 36.4% after 2013). The most common complications were vision loss, exophthalmos/proptosis, and orbital exenteration.

CONCLUSIONS AND RELEVANCE: This systematic review and meta-analysis suggests that the pooled proportion of AIFRS among immunocompromised patients has increased while mortality has declined, reflecting advances in diagnostic and therapeutic approaches. Early detection and aggressive management remain critical to improving outcomes.

PMID:41569597 | DOI:10.1001/jamaoto.2025.5077