A note on topological amenability

We point out a simple characterisation of topological amenability in terms of bounded cohomology, following Johnson's reformulation of amenability

Development of a Comprehensive Approach for the Early Diagnosis of Geriatric Syndromes in General Practice.

According to demographic projections, a significant increase in the proportion of the elderly population is anticipated worldwide. This aging of the population will lead to an increase in the prevalence of chronic diseases and functional impairment. This expected increase will result in growing use of the health care system that societies are largely unprepared to address. General practitioners (GPs) are at the front line of this huge epidemiological challenge, but appropriate tools to diagnose and manage elderly patients in routine general practice are lacking. Indeed, while primary prevention and the management of common chronic diseases, such as hypertension, diabetes, or cardiac ischemic diseases, are routinely and mostly adequately performed in primary care, the management of geriatric syndromes is often incomplete. In order to address these shortcomings, this theoretical work aims to first develop, based on the best available evidence, a brief assessment tool (BAT) specifically designed for geriatric syndromes identification in general practice and, second, to propose a conceptual framework for the management of elderly patients in general practice that integrates the BAT instrument into the usual care of GPs. To avoid proposing unachievable goals for the care of elderly patients in general practice (for example, performing all the best screening tools for geriatric conditions identification and care), this work proposes an innovative way to combine geriatric assessment with the management of common chronic diseases

A fixed point theorem for L 1 spaces

We prove a fixed point theorem for a family of Banach spaces including notably L 1 and its non-commutative analogues. Several applications are given, e.g. the optimal solution to the "derivation problem” studied since the 1960

A prospective study assessing agreement and reliability of a geriatric evaluation.

The present study takes place within a geriatric program, aiming at improving the diagnosis and management of geriatric syndromes in primary care. Within this program it was of prime importance to be able to rely on a robust and reproducible geriatric consultation to use as a gold standard for evaluating a primary care brief assessment tool. The specific objective of the present study was thus assessing the agreement and reliability of a comprehensive geriatric consultation. The study was conducted at the outpatient clinic of the Service of Geriatric Medicine, University of Lausanne, Switzerland. All community-dwelling older persons aged 70 years and above were eligible. Patients were excluded if they hadn't a primary care physician, they were unable to speak French, or they were already assessed by a geriatrician within the last 12 months. A set of 9 geriatricians evaluated 20 patients. Each patient was assessed twice within a 2-month delay. Geriatric consultations were based on a structured evaluation process, leading to rating the following geriatric conditions: functional, cognitive, visual, and hearing impairment, mood disorders, risk of fall, osteoporosis, malnutrition, and urinary incontinence. Reliability and agreement estimates on each of these items were obtained using a three-way Intraclass Correlation and a three-way Observed Disagreement index. The latter allowed a decomposition of overall disagreement into disagreements due to each source of error variability (visit, rater and random). Agreement ranged between 0.62 and 0.85. For most domains, geriatrician-related error variability explained an important proportion of disagreement. Reliability ranged between 0 and 0.8. It was poor/moderate for visual impairment, malnutrition and risk of fall, and good/excellent for functional/cognitive/hearing impairment, osteoporosis, incontinence and mood disorders. Six out of nine items of the geriatric consultation described in this study (functional/cognitive/hearing impairment, osteoporosis, incontinence and mood disorders) present a good to excellent reliability and can safely be used as a reference (gold standard) to evaluate the diagnostic performance of a primary care brief assessment tool. More objective/significant measures are needed to improve reliability of malnutrition, visual impairment, and risk of fall assessment before they can serve as a safe gold standard of a primary care tool

Amenable actions, free products and a fixed point property

We investigate the class of groups admitting an action on a set with an invariant mean. It turns out that many free products admit such an action. We give a complete characterisation of such free products in terms of a strong fixed point property.Comment: 12 page

On the distortion of twin building lattices

We show that twin building lattices are undistorted in their ambient group; equivalently, the orbit map of the lattice to the product of the associated twin buildings is a quasi-isometric embedding. As a consequence, we provide an estimate of the quasi-flat rank of these lattices, which implies that there are infinitely many quasi-isometry classes of finitely presented simple groups. In an appendix, we describe how non-distortion of lattices is related to the integrability of the structural cocycle

Property (T) and rigidity for actions on Banach spaces

We study property (T) and the fixed point property for actions on $L^p$ and other Banach spaces. We show that property (T) holds when $L^2$ is replaced by $L^p$ (and even a subspace/quotient of $L^p$), and that in fact it is independent of $1\leq p<\infty$. We show that the fixed point property for $L^p$ follows from property (T) when 1. For simple Lie groups and their lattices, we prove that the fixed point property for $L^p$ holds for any $1< p<\infty$ if and only if the rank is at least two. Finally, we obtain a superrigidity result for actions of irreducible lattices in products of general groups on superreflexive Banach spaces.Comment: Many minor improvement

Performance of a brief geriatric evaluation compared to a comprehensive geriatric assessment for detection of geriatric syndromes in family medicine: a prospective diagnostic study.

Geriatric syndromes are rarely detected in family medicine. Within the AGE program (active geriatric evaluation), a brief assessment tool (BAT) designed for family physicians (FP) was developed and its diagnostic performance estimated by comparison to a comprehensive geriatric assessment. This prospective diagnostic study was conducted in four primary care sites in Switzerland. Participants were aged at least 70 years and attending a routine appointment with their physician, without previous documented geriatric assessment. Participants were assessed by their family physicians using the BAT, and by a geriatriciant who performed a comprehensive geriatric assessment within the following two-month period (reference standard). Both the BAT and the full assessment targeted eight geriatric syndromes: cognitive impairment, mood impairment, urinary incontinence, visual impairment, hearing loss, undernutrition, osteoporosis and gait and balance impairment. Diagnostic accuracy of the BAT was estimated in terms of sensitivity, specificity, and predictive values; secondary outcomes were measures of feasibility, in terms of added consultation time and comprehensiveness in applying the BAT items. Prevalence of the geriatric syndromes in participants (N=85, 46 (54.1%) women, mean age 78 years (SD 6))ranged from 30.0% (malnutrition and cognitive impairment) to 71.0% (visual impairment), with a median number of 3 syndromes (IQR 2 to 4) per participant. Sensitivity of the BAT ranged from 25.0% for undernutrition (95%CI 9.8% - 46.7%) to 82.1% for hearing impairment (95%CI 66.5% - 92.5%), while specificity ranged from 45.8% for visual impairment (95%CI 25.6-67.2) to 87.7% for undernutrition (76.3% to 94.9%). Finally, most negative predictive values (NPV) were between 73.5% and 84.1%, excluding visual impairment with a NPV of 50.0%. Family physicians reported BAT use as per instructions for 76.7% of the syndromes assessed. Although the BAT does not replace a comprehensive geriatric assessment, it is a useful and appropriate tool for the FP to screen elderly patients for most geriatric syndromes. The study was registered on ClinicalTrials.gov on February 20, 2013 ( NCT01816087 )