Approche multidisciptinaire des coûts humains des lombalgies [Human cost of low back pain: a multi-disciplinary approach]

The valuation of human costs is a necessity, but this task poses many problems of method. A team made of a philosopher, a psychologist and a physician has been working with economist researchers in order to look into the meaning that the preferences announced at the time of the inquiries on human costs by QALY methods could assume. These methods are often used to obtain a valuation of the impact of a health attack on people's quality of life. The methods--in the frame of the argument assumed by the economic theory on well-being--hypothesize that people's choices depend mainly on cognitive work. The qualitative interviews show that the psychological construction process for the announced preferences largely overlap this frame. In this paper the authors hastily tackle the factors which have an effect on the preferences. They conclude that the QALY methods don't seem to be able to assess the quality of life nori to valuate the damage that the quality of life could include.

Electrophysiological markers of rapid cognitive decline in mild cognitive impairment

Electroencephalography (EEG) is an easily accessible and low-cost modality that might prove to be a particularly powerful tool for the identification of subtle functional changes preceding structural or metabolic deficits in progressive mild cognitive impairment (PMCI). Most previous contributions in this field assessed quantitative EEG differences between healthy controls, MCI and Alzheimer's disease(AD) cases leading to contradictory data. In terms of MCI conversion to AD, certain longitudinal studies proposed various quantitative EEG parameters for an a priori distinction between PMCI and stable MCI. However, cross-sectional comparisons revealed a substantial overlap in these parameters between MCI patients and elderly controls. Methodological differences including variable clinical definition of MCI cases and substantial interindividual differences within the MCI group could partly explain these discrepancies. Most importantly, EEG measurements without cognitive demand in both cross-sectional and longitudinal designs have demonstrated limited sensitivity and generally do not produce significant group differences in spectral EEG parameters. Since the evolution of AD is characterized by the progressive loss of functional connectivity within neocortical association areas, event-modulated EEG dynamic analysis which makes it possible to investigate the functional activation of neocortical circuits may represent a more sensitive method to identify early alterations of neuronal networks predictive of AD development among MCI cases. The present review summarizes clinically significant results of EEG activation studies in this field and discusses future perspectives of research aiming to reach an early and individual prediction of cognitive decline in healthy elderly controls.

Personality traits, behavioral and psychological symptoms and cognitive decline in patients at an early stage of Alzheimer's disease

The aim of this doctoral thesis was to study personality characteristics of patients at an early stage of Alzheimer's disease (AD), and more specifically to describe personality and its changes over time, and to explore its possible links with psychological and symptoms (BPS) and cognitive level. The results were compared to those of a group of participants without cognitive disorder through three empirical studies. In the first study, the findings showed significant personality changes that follow a specific trend in the clinical group. The profil of personality changes showed an increase in Neuroticism and a decrease in Extraversion, Openess to experiences, and Conscientiousness over time. The second study highlighted that personality and BPS occur early in the cours of AD. Recognizing them as possible precoce signs of neurodegeneration may prove to be a key factor for early detection and intervention. In the third study, a significant association between personality changes and cognitive status was observed in the patients with incipient AD. Thus, changes in Neuroticism and Conscientiousness were linked with cognitive deterioration, whereas decreased Openness to experiences and Conscientiousness over time predicted loss of independence in daily functioning. Other well-known factors such as age, education level or civil status were taken into account to predict cognitive decline. The three studies suggested five important implications: (1) cost-effective screening should take into account premorbid and specific personality changes; (2) psycho-educative interventions should provide information on the possible personality changes and BPS that may occur at the beginning of the disease; (3) using personality traits alongside other variables in the future studies on prevention might help to better understand AD's etiology; (4) individual treatment plans (psychotherapeutic, social, and pharmacological) might be adapted to the specific changes in personality profiles; (5) more researches are needed to study the impact of social-cultural and lifestyle variables on the development of AD.

Tunable lumped-element bandpass filters for Cognitive Radio application

In this thesis the design of bandpass filters tunable at 400 MHz – 800 MHz was under research. Microwave filters are vital components which provide frequency selectivity in wide variety of electronic systems operating at high frequencies. Due to the occurrence of multi-frequency bands communication and diverse applications of wireless devices, requirement of tunable filters exists. The one of potential implementation of frequency-agile filters is frontends and spectrum sensors in Cognitive Radio (CR). The principle of CR is to detect and operate at a particular available spectrum without interfering with the primary user’s signals. This new method allows improving the efficiency of utilizing allocated spectrum such as TV band (400 MHz – 800 MHz). The focus of this work is development of sufficiently compact, low cost tunable filters with quite narrow bandwidth using currently available lumped-element components and PCB board technology. Filter design, different topologies and methods of tuning of bandpass filters are considered in this work. As a result, three types of topologies of bandpass filter were simulated and realised. They use digitally tunable capacitors (DTCs) for adjusting central frequency at TV "white space" spectrum. Measurements revealed that schematics presented in this work have proper output response and filters are successfully tuned by DTCs.

Diagnosing dementia and normal aging: clinical relevance of brain ratios and cognitive performance in a Brazilian sample

The main objective of the present study was to evaluate the diagnostic value (clinical application) of brain measures and cognitive function. Alzheimer and multiinfarct patients (N = 30) and normal subjects over the age of 50 (N = 40) were submitted to a medical, neurological and cognitive investigation. The cognitive tests applied were Mini-Mental, word span, digit span, logical memory, spatial recognition span, Boston naming test, praxis, and calculation tests. The brain ratios calculated were the ventricle-brain, bifrontal, bicaudate, third ventricle, and suprasellar cistern measures. These data were obtained from a brain computer tomography scan, and the cutoff values from receiver operating characteristic curves. We analyzed the diagnostic parameters provided by these ratios and compared them to those obtained by cognitive evaluation. The sensitivity and specificity of cognitive tests were higher than brain measures, although dementia patients presented higher ratios, showing poorer cognitive performances than normal individuals. Normal controls over the age of 70 presented higher measures than younger groups, but similar cognitive performance. We found diffuse losses of tissue from the central nervous system related to distribution of cerebrospinal fluid in dementia patients. The likelihood of case identification by functional impairment was higher than when changes of the structure of the central nervous system were used. Cognitive evaluation still seems to be the best method to screen individuals from the community, especially for developing countries, where the cost of brain imaging precludes its use for screening and initial assessment of dementia.

Electrocortical indices of cognitive control in working memory : exploring the effects of proactive interference, cognitive load, and aging

Cognitive control involves the ability to flexibly adjust cognitive processing in order to resist interference and promote goal-directed behaviour. Although frontal cortex is considered to be broadly involved in cognitive control, the mechanisms by which frontal brain areas implement control functions are unclear. Furthermore, aging is associated with reductions in the ability to implement control functions and questions remain as to whether unique cortical responses serve a compensatory role in maintaining maximal performance in later years. Described here are three studies in which electrophysiological data were recorded while participants performed modified versions of the standard Sternberg task. The goal was to determine how top-down control is implemented in younger adults and altered in aging. In study I, the effects of frequent stimulus repetition on the interference-related N450 were investigated in a Sternberg task with a small stimulus set (requiring extensive stimulus resampling) and a task with a large stimulus set (requiring no stimulus resampling).The data indicated that constant stimulus res amp ling required by employing small stimulus sets can undercut the effect of proactive interference on the N450. In study 2, younger and older adults were tested in a standard version of the Sternberg task to determine whether the unique frontal positivity, previously shown to predict memory impairment in older adults during a proactive interference task, would be associated with the improved performance when memory recognition could be aided by unambiguous stimulus familiarity. Here, results indicated that the frontal positivity was associated with poorer memory performance, replicating the effect observed in a more cognitively demanding task, and showing that stimulus familiarity does not mediate compensatory cortical activations in older adults. Although the frontal positivity could be interpreted to reflect maladaptive cortical activation, it may also reflect attempts at compensation that fail to fully ameliorate agerelated decline. Furthermore, the frontal positivity may be the result of older adults' reliance on late occurring, controlled processing in contrast to younger adults' ability to identify stimuli at very early stages of processing. In the final study, working memory load was manipulated in the proactive interference Sternberg task in order to investigate whether the N450 reflects simple interference detection, with little need for cognitive resources, or an active conflict resolution mechanism that requires executive resources to implement. Independent component analysis was used to isolate the effect of interference revealing that the canonical N450 was based on two dissociable cognitive control mechanisms: a left frontal negativity that reflects active interference resolution, , but requires executive resources to implement, and a right frontal negativity that reflects global response inhibition that can be relied on when executive resources are minimal but at the cost of a slowed response. Collectively, these studies advance understanding of the factors that influence younger and older adults' ability to satisfy goal-directed behavioural requirements in the face of interference and the effects of age-related cognitive decline.

An Electrophysiological Investigation into the Role of Cognitive Control in the Attentional Blink

Accuracy at reporting a second-target (T2) is reduced if it is presented within approximately 500 ms of the first target (T1) – an attentional blink (AB). Early models explained the AB in terms of attentional limitations creating a processing bottleneck such that T2 processing would be impaired while T1 processing was ongoing. Theoretical models of the AB have more recently been expanded to include the role of cognitive control. In this dissertation I propose that cognitive control, defined as the optimization of information processing in order to achieve goals, is maladapted to the dual-task conditions of the AB task in that cognitive control optimizes the T1 goal, due to its temporal proximity, at the cost of T2. I start with the concept that the role of cognitive control is to serve goals, and that how goals are conceived of and the degree of motivation associated with those goals will determine whether cognitive control will create the condition that cause the AB. This leads to the hypothesis that electrophysiological measures of cognitive control and the degree of attentional investment resulting from cognitive control modulate the AB and explain individual differences in the AB. In a series of four studies feedback-related N2 amplitude, (reflecting individual differences in the strength of cognitive control), and event-related and resting alpha frequency oscillatory activity (reflecting degree of attentional investment), are used to explain both intra- and inter-individual variability in performance on the AB task. Results supported the hypothesis that stronger cognitive control and greater attentional investment are associated with larger AB magnitudes. Attentional investment, as measured by alpha frequency oscillations, and cognitive control, as measured by the feedback-related N2, did not relate to each other as hypothesized. It is proposed that instead of a measure of attentional investment alone, alpha frequency oscillatory activity actually reflects control over information processing over time, in other words the timing of attention. With this conceptualization, various aspects of cognitive control, either related to the management of goals (feedback-related N2) or the management of attention over time to meet goals, explain variability in the AB.

Economic evaluation of benzodiazepines versus cognitive behavioural therapy among older adults with chronic insomnia

L’insomnie, commune auprès de la population gériatrique, est typiquement traitée avec des benzodiazépines qui peuvent augmenter le risque des chutes. La thérapie cognitive-comportementale (TCC) est une intervention non-pharmacologique ayant une efficacité équivalente et aucun effet secondaire. Dans la présente thèse, le coût des benzodiazépines (BZD) sera comparé à celui de la TCC dans le traitement de l’insomnie auprès d’une population âgée, avec et sans considération du coût additionnel engendré par les chutes reliées à la prise des BZD. Un modèle d’arbre décisionnel a été conçu et appliqué selon la perspective du système de santé sur une période d’un an. Les probabilités de chutes, de visites à l’urgence, d’hospitalisation avec et sans fracture de la hanche, les données sur les coûts et sur les utilités ont été recueillies à partir d’une revue de la littérature. Des analyses sur le coût des conséquences, sur le coût-utilité et sur les économies potentielles ont été faites. Des analyses de sensibilité probabilistes et déterministes ont permis de prendre en considération les estimations des données. Le traitement par BZD coûte 30% fois moins cher que TCC si les coûts reliés aux chutes ne sont pas considérés (231$ CAN vs 335$ CAN/personne/année). Lorsque le coût relié aux chutes est pris en compte, la TCC s’avère être l’option la moins chère (177$ CAN d’économie absolue/ personne/année, 1,357$ CAN avec les BZD vs 1,180$ pour la TCC). La TCC a dominé l’utilisation des BZD avec une économie moyenne de 25, 743$ CAN par QALY à cause des chutes moins nombreuses observées avec la TCC. Les résultats des analyses d’économies d’argent suggèrent que si la TCC remplaçait le traitement par BZD, l’économie annuelle directe pour le traitement de l’insomnie serait de 441 millions de dollars CAN avec une économie cumulative de 112 billions de dollars canadiens sur une période de cinq ans. D’après le rapport sensibilité, le traitement par BZD coûte en moyenne 1,305$ CAN, écart type 598$ (étendue : 245-2,625)/personne/année alors qu’il en coûte moyenne 1,129$ CAN, écart type 514$ (étendue : 342-2,526)/personne/année avec la TCC. Les options actuelles de remboursement de traitements pharmacologiques au lieu des traitements non-pharmacologiques pour l’insomnie chez les personnes âgées ne permettent pas d’économie de coûts et ne sont pas recommandables éthiquement dans une perspective du système de santé.

WAIS Seminar:Evaluating the Cognitive Side of Information Interaction

Abstract In this talk, I'll focus on the work we've been doing on evaluating the cognitive side of dealing with information resources and increasingly complex user interfaces. While we can build increasingly powerful user interfaces, they often come at the cost of simple design and ease of use. I'll describe two specific studies: 1) work on the ORCHID project focused on measuring mental workload during tasks using fNIRS (a blood-oxygen-based brain scanner), and 2) a evaluation metric for measuring how much people learn during tasks. Together these provide advances towards understanding the cognitive side of information interaction, in working towards building better tools for users.

Cognitive therapy for anxiety disorders: current status and future directions.

This paper reviews recent theoretical, conceptual and practice developments in cognitive-behaviour therapy (CBT) for anxiety disorders. The empirical status of CBT for anxiety disorders is reviewed and recent advances in the field are outlined. Challenges for the future development of CBT for the anxiety disorders are examined in relation to the efficacy, effectiveness and cost-effectiveness of the approach. It is concluded that the major challenge currently facing CBT for anxiety disorders in the UK is how to meet the increased demand for provision whilst maintaining high levels of efficacy and effectiveness. It is suggested that the creation of an evidence base for the dissemination of CBT needs to become a priority for empirical investigation in order effectively to expand the provision of CBT for anxiety disorders.

Obsessive Compulsive Treatment Efficacy Trial (OCTET) comparing the clinical and cost effectiveness of self-managed therapies: study protocol for a randomised controlled trial

Background: UK National Institute of Health and Clinical Excellence guidelines for obsessive compulsive disorder (OCD) specify recommendations for the treatment and management of OCD using a stepped care approach. Steps three to six of this model recommend treatment options for people with OCD that range from low-intensity guided self-help (GSH) to more intensive psychological and pharmacological interventions. Cognitive behavioural therapy (CBT), including exposure and response prevention, is the recommended psychological treatment. However, whilst there is some preliminary evidence that self-managed therapy packages for OCD can be effective, a more robust evidence base of their clinical and cost effectiveness and acceptability is required. Methods/Design: Our proposed study will test two different self-help treatments for OCD: 1) computerised CBT (cCBT) using OCFighter, an internet-delivered OCD treatment package; and 2) GSH using a book. Both treatments will be accompanied by email or telephone support from a mental health professional. We will evaluate the effectiveness, cost and patient and health professional acceptability of the treatments. Discussion: This study will provide more robust evidence of efficacy, cost effectiveness and acceptability of self-help treatments for OCD. If cCBT and/or GSH prove effective, it will provide additional, more accessible treatment options for people with OCD.

Improving mood with psychoanalytic and cognitive therapies (IMPACT): a pragmatic effectiveness superiority trial to investigate whether specialised psychological treatment reduces the risk for relapse in adolescents with moderate to severe unipolar depression: study protocol for a randomised controlled trial

Background Up to 70% of adolescents with moderate to severe unipolar major depression respond to psychological treatment plus Fluoxetine (20-50 mg) with symptom reduction and improved social function reported by 24 weeks after beginning treatment. Around 20% of non responders appear treatment resistant and 30% of responders relapse within 2 years. The specific efficacy of different psychological therapies and the moderators and mediators that influence risk for relapse are unclear. The cost-effectiveness and safety of psychological treatments remain poorly evaluated. Methods/Design Improving Mood with Psychoanalytic and Cognitive Therapies, the IMPACT Study, will determine whether Cognitive Behavioural Therapy or Short Term Psychoanalytic Therapy is superior in reducing relapse compared with Specialist Clinical Care. The study is a multicentre pragmatic effectiveness superiority randomised clinical trial: Cognitive Behavioural Therapy consists of 20 sessions over 30 weeks, Short Term Psychoanalytic Psychotherapy 30 sessions over 30 weeks and Specialist Clinical Care 12 sessions over 20 weeks. We will recruit 540 patients with 180 randomised to each arm. Patients will be reassessed at 6, 12, 36, 52 and 86 weeks. Methodological aspects of the study are systematic recruitment, explicit inclusion criteria, reliability checks of assessments with control for rater shift, research assessors independent of treatment team and blind to randomization, analysis by intention to treat, data management using remote data entry, measures of quality assurance, advanced statistical analysis, manualised treatment protocols, checks of adherence and competence of therapists and assessment of cost-effectiveness. We will also determine whether time to recovery and/or relapse are moderated by variations in brain structure and function and selected genetic and hormone biomarkers taken at entry. Discussion The objective of this clinical trial is to determine whether there are specific effects of specialist psychotherapy that reduce relapse in unipolar major depression in adolescents and thereby costs of treatment to society. We also anticipate being able to utilise psychotherapy experience, neuroimaging, genetic and hormone measures to reveal what techniques and their protocols may work best for which patients.

Differences across health care systems in outcome and cost-utility of surgical and conservative treatment of chronic low back pain: a study protocol

BACKGROUND: There is little evidence on differences across health care systems in choice and outcome of the treatment of chronic low back pain (CLBP) with spinal surgery and conservative treatment as the main options. At least six randomised controlled trials comparing these two options have been performed; they show conflicting results without clear-cut evidence for superior effectiveness of any of the evaluated interventions and could not address whether treatment effect varied across patient subgroups. Cost-utility analyses display inconsistent results when comparing surgical and conservative treatment of CLBP. Due to its higher feasibility, we chose to conduct a prospective observational cohort study. METHODS: This study aims to examine if1. Differences across health care systems result in different treatment outcomes of surgical and conservative treatment of CLBP2. Patient characteristics (work-related, psychological factors, etc.) and co-interventions (physiotherapy, cognitive behavioural therapy, return-to-work programs, etc.) modify the outcome of treatment for CLBP3. Cost-utility in terms of quality-adjusted life years differs between surgical and conservative treatment of CLBP.This study will recruit 1000 patients from orthopaedic spine units, rehabilitation centres, and pain clinics in Switzerland and New Zealand. Effectiveness will be measured by the Oswestry Disability Index (ODI) at baseline and after six months. The change in ODI will be the primary endpoint of this study.Multiple linear regression models will be used, with the change in ODI from baseline to six months as the dependent variable and the type of health care system, type of treatment, patient characteristics, and co-interventions as independent variables. Interactions will be incorporated between type of treatment and different co-interventions and patient characteristics. Cost-utility will be measured with an index based on EQol-5D in combination with cost data. CONCLUSION: This study will provide evidence if differences across health care systems in the outcome of treatment of CLBP exist. It will classify patients with CLBP into different clinical subgroups and help to identify specific target groups who might benefit from specific surgical or conservative interventions. Furthermore, cost-utility differences will be identified for different groups of patients with CLBP. Main results of this study should be replicated in future studies on CLBP.

Can a novel computerized cognitive screening test provide additional information for early detection of Alzheimer's disease?

BACKGROUND: Virtual reality testing of everyday activities is a novel type of computerized assessment that measures cognitive, executive, and motor performance as a screening tool for early dementia. This study used a virtual reality day-out task (VR-DOT) environment to evaluate its predictive value in patients with mild cognitive impairment (MCI). METHODS: One hundred thirty-four patients with MCI were selected and compared with 75 healthy control subjects. Participants received an initial assessment that included VR-DOT, a neuropsychological evaluation, magnetic resonance imaging (MRI) scan, and event-related potentials (ERPs). After 12 months, participants were assessed again with MRI, ERP, VR-DOT, and neuropsychological tests. RESULTS: At the end of the study, we differentiated two subgroups of patients with MCI according to their clinical evolution from baseline to follow-up: 56 MCI progressors and 78 MCI nonprogressors. VR-DOT performance profiles correlated strongly with existing predictive biomarkers, especially the ERP and MRI biomarkers of cortical thickness. CONCLUSIONS: Compared with ERP, MRI, or neuropsychological tests alone, the VR-DOT could provide additional predictive information in a low-cost, computerized, and noninvasive way.

Improving brain injury cognitive rehabilitation by personalized telerehabilitation services: Guttmann neuropersonal trainer

Cognitive rehabilitation aims to remediate or alleviate the cognitive deficits appearing after an episode of acquired brain injury (ABI). The purpose of this work is to describe the telerehabilitation platform called Guttmann Neuropersonal Trainer (GNPT) which provides new strategies for cognitive rehabilitation, improving efficiency and access to treatments, and to increase knowledge generation from the process. A cognitive rehabilitation process has been modeled to design and develop the system, which allows neuropsychologists to configure and schedule rehabilitation sessions, consisting of set of personalized computerized cognitive exercises grounded on neuroscience and plasticity principles. It provides remote continuous monitoring of patient's performance, by an asynchronous communication strategy. An automatic knowledge extraction method has been used to implement a decision support system, improving treatment customization. GNPT has been implemented in 27 rehabilitation centers and in 83 patients' homes, facilitating the access to the treatment. In total, 1660 patients have been treated. Usability and cost analysis methodologies have been applied to measure the efficiency in real clinical environments. The usability evaluation reveals a system usability score higher than 70 for all target users. The cost efficiency study results show a relation of 1-20 compared to face-to-face rehabilitation. GNPT enables brain-damaged patients to continue and further extend rehabilitation beyond the hospital, improving the efficiency of the rehabilitation process. It allows customized therapeutic plans, providing information to further development of clinical practice guidelines.