20,916 research outputs found

    Psychological stress and cardiovascular disease: empirical demonstration of bias in a prospective observational study of Scottish men

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    Objectives: To examine the association between self perceived psychological stress and cardiovascular disease in a population where stress was not associated with social disadvantage. Design: Prospective observational study with follow up of 21 years and repeat screening of half the cohort 5 years from baseline. Measures included perceived psychological stress, coronary risk factors, self reported angina, and ischaemia detected by electrocardiography. Setting: 27 workplaces in Scotland. Participants: 5606 men (mean age 48 years) at first screening and 2623 men at second screening with complete data on all measures Main outcome measures: Prevalence of angina and ischaemia at baseline, odds ratio for incident angina and ischaemia at second screening, rate ratios for cause specific hospital admission, and hazard ratios for cause specific mortality. Results: Both prevalence and incidence of angina increased with increasing perceived stress (fully adjusted odds ratio for incident angina, high versus low stress 2.66, 95% confidence interval 1.61 to 4.41; P for trend <0.001). Prevalence and incidence of ischaemia showed weak trends in the opposite direction. High stress was associated with a higher rate of admissions to hospital generally and for admissions related to cardiovascular disease and psychiatric disorders (fully adjusted rate ratios for any general hospital admission 1.13, 1.01 to 1.27, cardiovascular disease 1.20, 1.00 to 1.45, and psychiatric disorders 2.34, 1.41 to 3.91). High stress was not associated with increased admission for coronary heart disease (1.00, 0.76-1.32) and showed an inverse relation with all cause mortality, mortality from cardiovascular disease, and mortality from coronary heart disease, that was attenuated by adjustment for occupational class (fully adjusted hazard ratio for all cause mortality 0.94, 0.81 to 1.11, cardiovascular mortality 0.91, 0.78 to 1.06, and mortality from coronary heart disease 0.98, 0.75 to 1.27). Conclusions: The relation between higher stress, angina, and some categories of hospital admissions probably resulted from the tendency of participants reporting higher stress to also report more symptoms. The lack of a corresponding relation with objective indices of heart disease suggests that these symptoms did not reflect physical disease. The data suggest that associations between psychosocial measures and disease outcomes reported from some other studies may be spurious

    Limitations of adjustment for reporting tendency in observational studies of stress and self reported coronary heart disease

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    Recently, observational evidence has been suggested to show a causal association between various "psychosocial" exposures, including psychological stress, and heart disease. Much of this evidence derives from studies in which a self reported psychosocial exposure is related to an outcome dependent on the subjective experience of coronary heart disease (CHD) symptoms. Such outcomes may be measured using standard symptom questionnaires (like the Rose angina schedule). Alternatively they may use diagnoses of disease from medical records, which depend on an individual perceiving symptoms and reporting them to a health worker. In these situations, reporting bias may generate spurious exposure-outcome associations. For example if people who perceive and report their life as most stressful also over-report symptoms of cardiovascular disease then an artefactual association between stress and heart disease will result

    Outcomes of an Evidence-Based, Data Driven-Model Fieldwork Experience for Occupational Therapy Students

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    Over the past decade, there has been an increased emphasis on evidence-based practice (EBP) and the use of outcome measurement in clinical practice, however, the implementation of evidence into practice remains challenging and irregular. During fieldwork, students often experience a disconnect between the emphasis on EBP in the classroom and lack of use in the clinic. Recognizing the need to develop high-quality, evidence-based and data-driven models of practice for student training, we partnered with local fieldwork educators to develop an innovative program that guides students and simultaneously trains fieldwork educators (FWE) in the use of a systematic data driven decision making (DDDM) process to infuse evidence into practice. Using a pre-post quasi-experimental design, we evaluated the impact of this program on students’ perceived knowledge and skills in use of EBP and DDDM. A focus group with participating fieldwork educators captured their knowledge and attitudes in the use of EBP and DDDM in their clinical sites. Eleven FWEs and twenty four students participated. Results revealed significant change in students’ knowledge and skill in use of EBP and DDDM. FWEs reported the program clarified the role of occupational therapy, enhanced communication, and validated the value of occupational therapy in their clinical site. This program serves as a model for training students to implement evidence and data driven approaches in clinical practice, thus bridging the gap between classroom and clinic

    Bose-enhanced chemistry: Amplification of selectivity in the dissociation of molecular Bose-Einstein condensates

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    We study the photodissociation chemistry of a quantum degenerate gas of bosonic triatomic ABCABC molecules, assuming two open rearrangement channels (AB+CAB+C or A+BCA+BC). The equations of motion are equivalent to those of a parametric multimode laser, resulting in an exponential buildup of macroscopic mode populations. By exponentially amplifying a small differential in the single-particle rate-coefficients, Bose stimulation leads to a nearly complete selectivity of the collective NN-body process, indicating a novel type of ultra-selective quantum degenerate chemistry.Comment: 5 pages, 3 figure

    Nonlocal Cosmology

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    We explore nonlocally modified models of gravity, inspired by quantum loop corrections, as a mechanism for explaining current cosmic acceleration. These theories enjoy two major advantages: they allow a delayed response to cosmic events, here the transition from radiation to matter dominance, and they avoid the usual level of fine tuning; instead, emulating Dirac's dictum, the required large numbers come from the large time scales involved. Their solar system effects are safely negligible, and they may even prove useful to the black hole information problem.Comment: Expanded(!) version, to appear in Phys. Rev. Letter

    Light Deflection, Lensing, and Time Delays from Gravitational Potentials and Fermat's Principle in the Presence of a Cosmological Constant

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    The contribution of the cosmological constant to the deflection angle and the time delays are derived from the integration of the gravitational potential as well as from Fermat's Principle. The findings are in agreement with recent results using exact solutions to Einstein's equations and reproduce precisely the new Λ\Lambda-term in the bending angle and the lens equation. The consequences on time delay expressions are explored. While it is known that Λ\Lambda contributes to the gravitational time delay, it is shown here that a new Λ\Lambda-term appears in the geometrical time delay as well. Although these newly derived terms are perhaps small for current observations, they do not cancel out as previously claimed. Moreover, as shown before, at galaxy cluster scale, the Λ\Lambda contribution can be larger than the second-order term in the Einstein deflection angle for several cluster lens systems.Comment: 6 pages, 1 figure, matches version published in PR

    Promoting Environments that Measure Outcomes: Partnerships for Change

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    This paper describes the development of the PrEMO© (Promoting Environments that Measure Outcomes) program. PrEMO© is an innovative model promoting evidence-based practice (EBP) while developing capacity and quality of Level II fieldwork placements. The PrEMO© program is described from initiation to completion, including development of site-specific learning objectives, the twelve week schedule and the role of faculty mentorship. Occupational therapy (OT) students, and university OT program faculty including academic fieldwork coordinators, partner with fieldwork educators at the site to implement EBP using a data-driven decision making (DDDM) process to guide the development of evidence-based practices. PrEMO© appears to be a useful strategy for building Level II fieldwork capacity and enhancing student and fieldwork educators’ knowledge and skills about EBP and outcome measurement in routine OT practice
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