Time-dependent prognostic accuracy measures for recurrent event data.

In many clinical contexts, the event of interest could occur multiple times for the same patient. Considerable advancement has been made on developing recurrent event models based on or that use biomarker information. However, less attention has been given to evaluating the prognostic accuracy of a biomarker or a composite score obtained from a fitted recurrent event-rate model.

Artificial Intelligence Assistive Software Tool for Automated Detection and Quantification of Amyloid-Related Imaging Abnormalities.

Importance: Amyloid-related imaging abnormalities (ARIA) are brain magnetic resonance imaging (MRI) findings associated with the use of amyloid-β-directed monoclonal antibody therapies in Alzheimer disease (AD). ARIA monitoring is important to inform treatment dosing decisions and might be improved through assistive software.

Objective: To assess the clinical performance of an artificial intelligence (AI)-based software tool for assisting radiological interpretation of brain MRI scans in patients monitored for ARIA.

Privacy-preserving analysis of time-to-event data under nested case-control sampling.

Analyses of distributed data networks of rare diseases are constrained by legitimate privacy and ethical concerns. Analytical centers (e.g.

Inference for covariate-adjusted time-dependent prognostic accuracy measures.

Evaluating the prognostic performance of candidate markers for future disease onset or progression is one of the major goals in medical research. A marker's prognostic performance refers to how well it separates patients at the high or low risk of a future disease state. Often the discriminative performance of a marker is affected by the patient characteristics (covariates).

Biomarker modeling of Alzheimer's disease using PET-based Braak staging.

Gold-standard diagnosis of Alzheimer's disease (AD) relies on histopathological staging systems. Using the topographical information from [F]MK6240 tau positron-emission tomography (PET), we applied the Braak tau staging system to 324 living individuals. We used PET-based Braak stage to model the trajectories of amyloid-β, phosphorylated tau (pTau) in cerebrospinal fluid (pTau, pTau, pTau and pTau) and plasma (pTau and pTau), neurodegeneration and cognitive symptoms.

Association of Phosphorylated Tau Biomarkers With Amyloid Positron Emission Tomography vs Tau Positron Emission Tomography.

Importance: The recent proliferation of phosphorylated tau (p-tau) biomarkers has raised questions about their preferential association with the hallmark pathologies of Alzheimer disease (AD): amyloid-β plaques and tau neurofibrillary tangles.

Objective: To determine whether cerebrospinal fluid (CSF) and plasma p-tau biomarkers preferentially reflect cerebral β-amyloidosis or neurofibrillary tangle aggregation measured with positron emission tomography (PET).

Design, Setting, And Participants: This was a cross-sectional study of 2 observational cohorts: the Translational Biomarkers in Aging and Dementia (TRIAD) study, with data collected between October 2017 and August 2021, and the Alzheimer's Disease Neuroimaging Initiative (ADNI), with data collected between September 2015 and November 2019.

Intrinsic connectivity of the human brain provides scaffold for tau aggregation in clinical variants of Alzheimer's disease.

Alzheimer's disease (AD) phenotypes might result from differences in selective vulnerability. Evidence from preclinical models suggests that tau pathology has cell-to-cell propagation properties. Therefore, here, we tested the cell-to-cell propagation framework in the amnestic, visuospatial, language, and behavioral/dysexecutive phenotypes of AD.

A three-range approach enhances the prognostic utility of CSF biomarkers in Alzheimer's disease.

Introduction: Alzheimer's disease consensus recommends biomarker dichotomization, a practice with well-described clinical strengths and methodological limitations. Although neuroimaging studies have explored alternative biomarker interpretation strategies, a formally defined three-range approach and its prognostic impact remains under-explored for cerebrospinal fluid (CSF) biomarkers .

Methods: With two-graph receiver-operating characteristics based on different reference schemes, we derived three-range cut-points for CSF Elecsys biomarkers.

Feasibility, Acceptability, and Clinical Significance of a Dyadic, Web-Based, Psychosocial and Physical Activity Self-Management Program () Tailored to the Needs of Men with Prostate Cancer and Their Caregivers: A Multi-Center Randomized Pilot Trial.

Background: Prostate cancer is the most common cancer diagnosis among men. Family caregivers (often female spouses) play a key role in ensuring patients' needs are met, frequently assuming their role with no formal training, which can contribute to a high burden. The purpose of this study was to pilot -the first dyadic, Tailored, wEb-based, psychosocial and physical activity self-Management PrOgram for men with prostate cancer and their caregivers.

Model-Based ROC Curve: Examining the Effect of Case Mix and Model Calibration on the ROC Plot.

Background: The performance of risk prediction models is often characterized in terms of discrimination and calibration. The receiver-operating characteristic (ROC) curve is widely used for evaluating model discrimination. However, when comparing ROC curves across different samples, the effect of case mix makes the interpretation of discrepancies difficult.

Amyloid-dependent and amyloid-independent effects of Tau in individuals without dementia.

Objective: To investigate the relationship between the topography of amyloid-β plaques, tau neurofibrillary tangles, and the overlap between the two, with cognitive dysfunction in individuals without dementia.

Methods: We evaluated 154 individuals who were assessed with amyloid-β PET with [ F]AZD4694, tau-PET with [ F]MK6240, structural MRI, and neuropsychological testing. We also evaluated an independent cohort of 240 individuals who were assessed with amyloid-β PET with [ F]Florbetapir, tau-PET with [ F]Flortaucipir, structural MRI, and neuropsychological testing.

Association of plasma P-tau181 with memory decline in non-demented adults.

Alzheimer's disease is the leading cause of dementia worldwide and is characterized by a long preclinical phase in which amyloid-β and tau accumulate in the absence of cognitive decline. biomarkers for Alzheimer's disease are expensive, invasive and inaccessible, yet are critical for accurate disease diagnosis and patient management. Recent ultrasensitive methods to measure plasma phosphorylated tau 181 (p-tau181) display strong correlations with tau positron emission tomography, p-tau181 in CSF, and tau pathology at autopsy.

Plasma pTau181 predicts cortical brain atrophy in aging and Alzheimer's disease.

Background: To investigate the association of plasma pTau181, assessed with a new immunoassay, with neurodegeneration of white matter and gray matter cross-sectionally and longitudinally, in aging and Alzheimer's disease.

Methods: Observational data was obtained from the Alzheimer's Disease Neuroimaging Initiative, in which participants underwent plasma assessment and magnetic resonance imaging. Based on their clinical diagnosis, participants were classified as cognitively unimpaired and cognitively impaired.

A study protocol for a multicenter randomized pilot trial of a dyadic, tailored, web-based, psychosocial, and physical activity self-management program (TEMPO) for men with prostate cancer and their caregivers.

Background: Prostate cancer predisposes patients and caregivers to a wide range of complex physical and psychosocial challenges, and interventions must incorporate a wide range of self-management strategies to help patients and their caregivers effectively cope with cancer challenges. To palliate this need, our team recently developed and evaluated the initial acceptability of a dyadic, Tailored, wEb-based, psychosocial, and physical activity self-Management PrOgram (TEMPO). TEMPO is a 10-week, interactive, web-based intervention consisting of five modules designed to help dyads manage their physical and psychosocial needs.

Frequency of Biologically Defined Alzheimer Disease in Relation to Age, Sex, ε4, and Cognitive Impairment.

Objective: To assess the frequency of biologically defined Alzheimer disease (AD) in relation to age, sex, ε4, and clinical diagnosis in a prospective cohort study evaluated with amyloid-PET and tau-PET.

Methods: We assessed cognitively unimpaired (CU) elderly (n = 166), patients with amnestic mild cognitive impairment (n = 77), and patients with probable AD dementia (n = 62) who underwent evaluation by dementia specialists and neuropsychologists in addition to amyloid-PET with [F]AZD4694 and tau-PET with [F]MK6240. Individuals were grouped according to their AD biomarker profile.

Survival analysis under the Cox proportional hazards model with pooled covariates.

For a continuous time-to-event outcome and an expensive-to-measure exposure, we develop a pooling design and propose a likelihood-based approach to estimate the hazard ratios (HRs) of a Cox proportional hazards (PH) model. Our proposed approach fits a PH model based on pooled exposures with individually observed time-to-event outcomes. The design and estimation exploits the equivalence of the conditional logistic likelihood functions arising from a matched case-control study and the partial likelihood function of a riskset-matched, nested case-control (NCC) subset of a cohort study.

The nurse pivot-navigator associated with more positive cancer care experiences and higher patient satisfaction.

Background And Objectives: Growing evidence indicates that the nurse navigator-pivot (NN), is key to optimizing care processes and outcomes. However, large scale studies are needed to examine how patients exposed to NNs (as opposed to non-NN) differentially perceived their cancer care experiences.

Method: Participants (N = 2,858) treated for cancer in the last six months at university-affiliated cancer centres in Montréal, Québec, completed the Ambulatory Oncology Patient Satisfaction Survey (AOPSS).

L'infirmière pivot associée à une expérience de soins oncologiques positive et à une satisfaction accrue des patients.

Contexte Et Objectifs: Un nombre croissant de résultats probants indique que l'infirmière pivot en oncologie (IPO) joue un rôle de premier plan dans l'optimisation des processus et des résultats de soins. Il faudra toutefois mener des études d'envergure pour comparer les perceptions de l'expérience de soins liés au cancer des patients traités par des infirmières pivots et de ceux qui n'ont pas bénéficié de ce type de suivi.

MÉthodologie: Des participants (N = 2 858) traités au cours des six derniers mois dans un centre de traitement du cancer situé à Montréal, au Québec, et affilié à une université ont répondu au sondage sur la satisfaction des patients en traitement anticancéreux ambulatoire, c'est-à-dire le Ambulatory Oncology Patient Satisfaction Survey (AOPSS).

Diagnostic performance and prediction of clinical progression of plasma phospho-tau181 in the Alzheimer's Disease Neuroimaging Initiative.

Whilst cerebrospinal fluid (CSF) and positron emission tomography (PET) biomarkers for amyloid-β (Aβ) and tau pathologies are accurate for the diagnosis of Alzheimer's disease (AD), their broad implementation in clinical and trial settings are restricted by high cost and limited accessibility. Plasma phosphorylated-tau181 (p-tau181) is a promising blood-based biomarker that is specific for AD, correlates with cerebral Aβ and tau pathology, and predicts future cognitive decline. In this study, we report the performance of p-tau181 in >1000 individuals from the Alzheimer's Disease Neuroimaging Initiative (ADNI), including cognitively unimpaired (CU), mild cognitive impairment (MCI) and AD dementia patients characterized by Aβ PET.

Topographic Distribution of Amyloid-β, Tau, and Atrophy in Patients With Behavioral/Dysexecutive Alzheimer Disease.

Objective: To determine the associations between amyloid-PET, tau-PET, and atrophy with the behavioral/dysexecutive presentation of Alzheimer disease (AD), how these differ from amnestic AD, and how they correlate to clinical symptoms.

Methods: We assessed 15 patients with behavioral/dysexecutive AD recruited from a tertiary care memory clinic, all of whom had biologically defined AD. They were compared with 25 patients with disease severity- and age-matched amnestic AD and a group of 131 cognitively unimpaired (CU) elderly individuals.