A cost-effectiveness analysis is used to compare two alternative strategies for the control of tuberculosis in facilities providing long-term care to the elderly: (1) systematic screening of all new residents with the Mantoux test to identify persons infected with the tubercule bacillus, and preventive treatment of those who are most at risk of tuberculosis as recommended by the U.S. Department of Health and Human Services and (2) clinical follow-up of the index-case contacts as recommended by the Quebec Ministry of Health and Social Services. Incremental effectiveness and cost associated with the American strategy are estimated with a Markov model applied to the Quebec long-term care facilities population. Costs are estimated in the perspective of the health care system. Even though complications due to isoniazid chemoprophylaxis cluster in the year following admission, the American approach is advantageous. At the end of the implementation phase throughout the province of Quebec, this approach prevents 32 cases of tuberculosis annually. The incremental cost is 121 626$ per year for the entire province, 3 822 $ per case avoided, 9 555$ per death avoided, 3 437 $ per life-year saved and 2 756$ per quality-adjusted life-years saved. Those costs compare favourably to other health prevention measures recommended for the elderly population.

Children with chronic illnesses have a doubled risk of developing psychosocial maladjustment--emotional problems, behavior disorder or difficulties in social relationships. Social work support and counselling aims to reduce this secondary morbidity, and is a common form of hospital-based psychosocial service. The first randomized controlled trial of this type of intervention was carried out to evaluate its effectiveness in treating and preventing maladjustment. This thesis describes how child behavior outcomes were assessed before and 4 months after a 6 month period of social worker assistance in 173 children randomized to intervention, and in 169 controls, all with chronic illnesses. / No significant difference between intervention and control groups in the overall prevalence of maladjustment was found. There was no evidence to support a therapeutic or preventive effect of social work counselling on child behavior outcomes, nor was there improvement in child perceived competence. A search for treatment interactions failed to reveal any sub-group that benefitted from the intervention, and restriction of the analysis to individuals who actually received the intervention does not alter any of these conclusions. / Measurement problems, co-intervention, or other forms of bias cannot account for the negative results. It is speculated that if social work support is to be effective, it should be targetted, potent, of adequate duration, and possibly integrated within specialist clinic services.

Rheological behavior and flow induced fiber orientation in simple flows of short glass fiber reinforced polypropylene melts were studied. Transient and steady state properties and in situ fiber orientation distribution were measured in simple shear flow, poiseuille flow, small amplitude oscillatory shear and uni-axial extensional flow. Strong correlation is found between the flow induced changes in fiber orientation distribution and measured bulk rheological properties. / An extension of suspension theories for dilute systems is proposed, where multi-particle interactions are modeled as a randomizing process. The effect of non-Newtonian fluid properties is incorporated at the slow flow limit through its effect on the fiber orientation only. Model predictions for simple shear demonstrate the strong correlation between the changes in fiber orientation and bulk rheological properties. Model predictions are in qualitative agreement with experimental observations in simple shear flow.

In order to understand and document the patterns of smoking among youth, the use of reliable and valid measures is essential. The current analysis uses data on 63 ever smokers (mean age 14.1 years) from the first three years of follow-up of the McGill University Study on the Natural History of Nicotine Dependence In Teens. To examine reliability, we compared responses to one-month recall to three-month recall of the subjects' smoking history. The questionnaire demonstrated very good reliability for smoking intensity (kappa = 0.75) and smoking frequency (kappa = 0.78). Number of cigarettes smoked per month showed good reliability (ICC = 0.64). Reliability remained acceptable when subjects who reported no cigarette consumption at both questionnaire administrations were excluded (kappa = 0.66; kappa = 0.70; ICC = 0.61, respectively). Older adolescents (14--16) were better at recalling their smoking history than younger adolescents (12--13). Female sex and smoking status (sporadic versus regular) were associated with adequate recall for one and two of the indicators investigated, respectively.

It has recently been demonstrated that a continuum of self-management (SM) for COPD patients provided by a trained health professional significantly reduce the utilisation of health care services (Bourbeau et al Arch Intern Med March 2003). The objective of the present study was to assess in COPD patients who received a self-management program of the beneficial effect of reduce hospitalisation could be maintained at long term. A multicentre, randomised clinical trial was carried out in 191 COPD patients from 7 hospitals. Patients who all had one hospitalisation in the year preceding study enrolment were assigned to a self-management program or to usual care. The self-management program "Living Well with COPD(c)" consisted of a multi-component patient education program administered through weekly visits by trained health professionals over a 2 months period with monthly telephone follow-up for 12 months. All cause hospitalisations, the main outcome, were marked using the provincial hospital database (MED-ECHO). / Most patients were elderly, not highly educated and had advanced COPD reflected by a mean FEV1 of 1L and 46% reported a dyspnea score of 5/5 (modified MRC). / The long-term effectiveness of the self-management program was assessed with an intention-to-threat analysis. The group-level chi-square analysis shows a statistically significant difference of 29% in the rate of all-cause hospitalization between the intervention group and the usual-care group. The individual-level proportional odds model analysis shows a statistically significant risk estimate of 0.566. / The study shows that patients with COPD, who received an education intervention with supervision and support based on disease specific self-management, still had a significant reduction in hospitalisations at 2 years. Within normal practice such program should be an integral part of the continuum of care of patients with COPD.

The consequences of stroke extend beyond the individual who has sustained the stroke to include family members, the main providers of care to community dwelling stroke survivors. Caregiver research, for the most part, has focused on burden and distress. Although there is a growing consensus among health care researchers concerning the relevance of quality of life (QoL) as an outcome, there is little research examining QoL among family caregivers and even less focused on conceptualization of the construct. This thesis was designed to address these gaps in theory and measurement through a series of related studies. / The development of a conceptual model of QoL for family caregivers, that includes the caregiving situation, caregiver characteristics, and environmental factors, and their proposed relationships with QoL, provided a framework for the measurement and study of QoL. Relationships between patient characteristics, caregiver burden, and health-related quality of life (HRQL) were examined over the first two years of caregiving and the results confirmed the impact of the caregiving role on the caregiver's emotional health, and additionally, supported the need for a specific measure of overall QoL to more fully capture the caregiving experience. / A subsequent study was conducted to develop this measure of QoL for family caregivers of stroke survivors. Data from several different samples of family caregivers contributed to the specific phases required in measure development and psychometric testing. Four sub-scales, 'health', 'resources', 'role mastery', and 'rewards', were constructed. Although the overall psychometric properties of this measure are promising, they also indicate the need for further development of selected items and the 'rewards' subscale measuring the positive dimension. / The specific hypotheses concerning the relationships among the variables in the conceptual framework of QoL of family caregivers were tested using structural equation modeling and they were partially supported. The results suggest several approaches for intervening with family caregivers. As restructuring of health care delivery is placing more responsibility for the care of disabled members on the family, we require effective interventions to ensure that we preserve this valuable commodity.

Background: The question whether certain cognitive domains in schizophrenia qualify as disproportionate/core impairments against a back-drop of generalized deficits remains unresolved. Investigating more homogeneous subgroups of patients may enhance our understanding of the exact nature of disproportionate deficits. / Method: One-hundred and twenty-one patients attending an early psychosis program completed a neuropsychological battery comprising of six cognitive domains and IQ. Symptom severity and pre-morbid adjustment were also assessed. / Results: Early psychosis patients with high levels of negative symptoms and "stable-poor" pre-morbid functioning have severe generalized cognitive impairment. Patients with low levels of negative symptoms and "stable-good" pre-morbid adjustment present with milder generalized impairments. / Conclusion: Contrary to our hypothesis, visual memory appears to be disproportionally impaired against a back-drop of severe generalized cognitive deficits in early psychosis patients. Patients who have a consistently poor (stable-poor) course pre-morbid adjustment and those with high levels of negative symptoms are more impaired. / Contexte: Les déficits cognitifs sont hétérogènes chez les schizophrènes. La question reliée à la présence de certains déficits cognitifs disproportionnés par rapport à un déficit généralisé reste non-résolue. L`étude de sous-groupes de patients plus homogènes au niveau de la sévérité des symptômes et du fonctionnement prémorbide pourrait éclairer notre compréhension entourant la nature exacte des déficits disproportionnés. / Méthode : Cent-vingt et un patients suivis dans un programme de premier épisode psychotique ont complété une batterie neuropsychologique complète évaluant cinq domaines cognitifs et le QI global. La sévérité des symptômes et le fonctionnement prémorbide ont aussi été évalués. / Résultats : Dans un échantillon hétérogène de premier épisode de psychose, les patients présentent des déficits cognitifs généralisés sévères. En classifiant les patients en sous-groupes, ceux avec de hauts niveaux de symptômes négatifs et un fonctionnement prémorbide «stable-pauvre » présentent des déficits cognitifs généralisés sévères. Les patients avec peu de symptômes négatifs et un fonctionnement prémorbide « stable-bon » démontrent des déficits généralisés plus modérés. / Conclusion: Nos résultats indiquent la présence de sévères déficits cognitifs au niveau de la mémoire visuelle et de la vitesse de traitement de l`information chez les jeunes souffrant d`un premier épisode de psychose. De plus, il semble plus prononcés chez les patients avec un fonctionnement prémorbide «stable-pauvre ».

We examined the effects of bright light on social interaction and mood in healthy individuals with mild seasonality. In a cross-over design, 38 mildly seasonal individuals received three weeks of bright light and three weeks of placebo (low-density negative ions). Using an event-contingent method participants recorded their mood and behaviours during social interactions and wore a light-sensor actigraphy at the wrist to monitor adherence to home based light exposure. During light administration, 23 participants adhered to the light protocol and exhibited more quarrelsome behaviours and no change in mood. Participants who provided no evidence of adherence had similar mood and social behaviour during both interventions. The results indicate the need for effective methods for determining adherence to the protocol in light studies. Furthermore, in individuals with mild seasonality light administration may not improve mood and may have adverse effects on social behaviour. / Nous avons examiné les effets de la lumière forte sur les interactions sociales et l'humeur chez des individus sains avec un caractère saisonnier léger. En utilisant un plan d'étude croisé, 38 individus légèrement saisonniers ont été exposés à trois semaines de lumière forte et trois semaines d'un placebo (ions négatifs à intensité basse). En utilisant la méthode des événements liés (les participants ont enregistré leur humeur et comportement durant leurs interactions sociales et ont porté un détecteur de lumière au poignet pour vérifier leur adhérence à l'exposition à la lumière à la maison. Durant l'administration de la lumière, 23 participants ont adhéré au protocole de lumière et exhibé plus de comportements querelleurs et aucun changement d'humeur. Parmi les autres participants qui n'ont fourni aucune preuve d'adhérence, et leur humeur et comportement social étaient semblables pendant les deux interventions. Les résultats indiquent un besoin de méthodes efficaces pour déterminer l'adhérence au protocole de lumière. Qui plus est, chez les individus avec caractère saisonnier léger, il est possible que l'administration de lumière n'améliore pas l'humeur et exerce des effets adverses sur le comportement social. fr

This thesis examines the relationship between trauma and psychosis among refugees who were tortured. In particular, it analyses the systems of meaning and the phenomenology of the symptoms through a triangulation of perspectives, namely that of the patients, their family or friends and clinicians. It uses a multiple case study design to analyse interviews of three triads and two diads in depth. Results show an important phenomenological overlap between trauma and psychosis, regarding symptoms. They also show a divergence between the patients' systems of meanings and the clinicians' regarding the importance and the role of trauma in the onset of psychosis. / Ce mémoire examine la question des liens entre trauma et psychose chez des réfugiés victimes de torture. Il analyse en particulier les systèmes de sens et la phénoménologie des symptômes à travers une triangulation des perspectives: celle des patients, de leur entourage et de leurs intervenants. Il s'agit d'une étude de cas multiples dans laquelle les entretiens de trois triades et deux dyades sont analysés en profondeur. Les résultats témoignent d'un fort recouvrement phénoménologique entre trauma et psychose au niveau des symptômes. Au niveau des systèmes de sens, on trouve un décalage de perspectives entre les patients et leurs intervenants quant à l'importance et au rôle du trauma dans le développement de la psychose.

Gender differences in suicidal behaviour entail a challenging paradox: more women attempt suicide than men, while more men commit suicide than women. The majority of suicide victims have a history of major depressive disorder (MDD), though only a small minority of those suffering from MDD will die by suicide. The present study aimed to explore the moderating role of gender in suicide completion, with particular focus on personality predispositions, Axis I and II psychopathology, while controlling for the effect of MDD. In the context of a case-control design, 201 suicide completers (160 men and 41 women) and 129 living controls (90 men and 39 women) with a history of MDD were recruited in Montreal, Canada. Participants were evaluated via the psychological autopsy method. Differences were found between men and women in the significant risk factors, suggesting that psychopathology and predispositions related to impulsivity-aggressivity and impulse-dyscontrol may have different relative contributions to suicide in depressed men and women. / Les différences dans le comportement suicidaire entre les hommes et les femmes, un paradoxe: Plus de femmes que d'hommes font des tentatives de suicide bien que plus d'hommes que de femmes les réussissent. La majorité des vicitimes du suicide ont des antécédents de trouble de dépression majeur (MDD), même si seulement une faible minorité des personnes atteintes de MDD vont mettre fin à leurs jours. La présente étude entend relativiser l'importance du genre chez les personnes qui se sont suicidées en mettant l'accent plus particulièrement sur les prédispositions propres à chaque individu, la psychopathologie de l'axe I et II, en contrôlant les effets du MDD. Les cas présentés, 201 suicides (160 hommes et 41 femmes) et 129 tentatives de suicide (90 hommes et 39 femmes) ont été recrutés à Montréal, Canada. Les participants ont été évalués selon la méthode de l'autopsie psychologique. En ce qui a trait aux facteurs de risque, des différences ont été notées entre les hommes et les femmes, ce qui laisse entendre que la psychopathologie et les prédispositions relatives à l'impulsivité-agressivité ainsi qu'au non-contrôle-impulsif peuvent avoir contribués différement au suicide chez les hommes et les femmes en dépression.