35 research outputs found

    Bias and Precision of the Squared Canonical Correlation Coefficient Under Nonnormal Data Condition

    Get PDF
    Monte Carlo methods were employed to investigate the effect of nonnormality on the bias associated with the squared canonical correlation coefficient (Rc2). The majority of Rc2 estimates were found to be extremely biased, but the magnitude of bias was impacted little by the degree of nonnormality

    Development of a caregiver-reported measure to support systematic assessment of people with dementia in long-term care: The Integrated Palliative care Outcome Scale for Dementia

    Get PDF
    Background:Symptom burden is common for long-term care residents with dementia which if untreated compromises quality of life. Measurement tools can support assessment of symptoms and problems but are not widely used in long-term care settings. We developed the Integrated Palliative care Outcome Scale for Dementia derived from the Palliative care Outcome Scale, Palliative care Outcome Scale–Symptom and Integrated Palliative care Outcome Scale.Aim:To examine the content validity, acceptability and comprehension of Integrated Palliative care Outcome Scale for Dementia for routine use in long-term care settings for people with dementia and to refine Integrated Palliative care Outcome Scale for Dementia.Design:A multi-method qualitative study consisting of focus groups, semi-structured interviews and cognitive interviews.Setting/participants:Three residential long-term care settings in London, UK. Focus group and semi-structured interview participants included caregiver staff, family, general practitioners and district nurses. Caregiver staff were sampled purposively for cognitive interviews.Results:A total of 26 respondents participated in the focus groups (n = 21) or semi-structured interviews (n = 5) and 10 caregiver staff completed cognitive interviews. Additional symptoms and problems included agitation, wandering, sleep problems, communication problems and diarrhoea. Refinements or lay terms were required to improve comprehension and consistency of item response for nausea, drowsiness, delusions/hallucinations, agitation, loss of interest, communication problems and interaction. A video presentation was required to support comprehension of instructions and assessment of verbally compromised residents.Conclusion:Integrated Palliative care Outcome Scale for Dementia is a comprehensive and acceptable caregiver-reported measure to detect symptoms and problems in dementia. It is suitable for caregiver staff without professional training as it has been refined and tailored to maximise caregiver expertise, ready for further psychometric testing

    The real-world problem of care coordination: a longitudinal qualitative study with patients living with advanced progressive illness and their unpaid caregivers.

    Get PDF
    OBJECTIVES: To develop a model of care coordination for patients living with advanced progressive illness and their unpaid caregivers, and to understand their perspective regarding care coordination. DESIGN: A prospective longitudinal, multi-perspective qualitative study involving a case-study approach. METHODS: Serial in-depth interviews were conducted, transcribed verbatim and then analyzed through open and axial coding in order to construct categories for three cases (sites). This was followed by continued thematic analysis to identify underlying conceptual coherence across all cases in order to produce one coherent care coordination model. PARTICIPANTS: Fifty-six purposively sampled patients and 27 case-linked unpaid caregivers. SETTINGS: Three cases from contrasting primary, secondary and tertiary settings within Britain. RESULTS: Coordination is a deliberate cross-cutting action that involves high-quality, caring and well-informed staff, patients and unpaid caregivers who must work in partnership together across health and social care settings. For coordination to occur, it must be adequately resourced with efficient systems and services that communicate. Patients and unpaid caregivers contribute substantially to the coordination of their care, which is sometimes volunteered at a personal cost to them. Coordination is facilitated through flexible and patient-centered care, characterized by accurate and timely information communicated in a way that considers patients' and caregivers' needs, preferences, circumstances and abilities. CONCLUSIONS: Within the midst of advanced progressive illness, coordination is a shared and complex intervention involving relational, structural and information components. Our study is one of the first to extensively examine patients' and caregivers' views about coordination, thus aiding conceptual fidelity. These findings can be used to help avoid oversimplifying a real-world problem, such as care coordination. Avoiding oversimplification can help with the development, evaluation and implementation of real-world coordination interventions for patients and their unpaid caregivers in the future

    Social and clinical determinants of preferences and their achievement at the end of life: Prospective cohort study of older adults receiving palliative care in three countries

    Get PDF
    © 2017 The Author(s). Background: Achieving choice is proposed as a quality marker. But little is known about what influences preferences especially among older adults. We aimed to determine and compare, across three countries, factors associated with preferences for place of death and treatment, and actual site of death. Methods: We recruited adults aged ≥65-years from hospital-based multiprofessional palliative care services in London, Dublin, New York, and followed them for >17 months. All services offered consultation on hospital wards, support for existing clinical teams, outpatient services and received funding from their National Health Service and/or relevant Insurance reimbursements. The New York service additionally had 10 inpatient beds. All worked with and referred patients to local hospices. Face-to-face interviews recorded most and least preferred place of death, treatment goal priorities, demographic and clinical information using validated questionnaires. Multivariable and multilevel analyses assessed associated factors. Results: One hundred and thirty eight older adults (64 London, 59 Dublin, 15 New York) were recruited, 110 died during follow-up. Home was the most preferred place of death (77/138, 56%) followed by inpatient palliative care/hospice units (22%). Hospital was least preferred (35/138, 25%), followed by nursing home (20%) and home (16%); hospice/palliative care unit was rarely least preferred (4%). Most respondents prioritised improving quality of life, either alone (54%), or equal with life extension (39%); few (3%) chose only life extension. There were no significant differences between countries. Main associates with home preference were: cancer diagnosis (OR 3.72, 95% CI 1.40-9.90) and living with someone (OR 2.19, 1.33-3.62). Adults with non-cancer diagnoses were more likely to prefer palliative care units (OR 2.39, 1.14-5.03). Conversely, functional independence (OR 1.05, 1.04-1.06) and valuing quality of life (OR 3.11, 2.89-3.36) were associated with dying at home. There was a mismatch between preferences and achievements - of 85 people who preferred home or a palliative care unit, 19 (25%) achieved their first preference. Conclusion: Although home is the most common first preference, it is polarising and for 16% it is the least preferred. Inpatient palliative care unit emerges as the second most preferred place, is rarely least preferred, and yet was often not achieved for those who wanted to die there. Factors affecting stated preferences and met preferences differ. Available services, notably community support and palliative care units, require expansion. Contrasting actual place of death with capacity for meeting patient and family needs may be a better quality indicator than simply 'achieved preferences'

    Decreasing the expression of PICALM reduces endocytosis and the activity of β-secretase: Implications for Alzheimer's disease

    Get PDF
    © 2016 The Author(s). Background: Polymorphisms in the gene for phosphatidylinositol binding clathrin assembly protein (PICALM), an endocytic-related protein, are associated with a small, increased risk of developing Alzheimer's disease (AD), strongly suggesting that changes in endocytosis are involved in the aetiology of the disease. We have investigated the involvement of PICALM in the processing of amyloid precursor protein (APP) to understand how PICALM could be linked to the development of AD. We used siRNA to deplete levels of PICALM, its isoforms and clathrin heavy chain in the human brain-derived H4 neuroglioma cell line that expresses endogenous levels of APP. We then used Western blotting, ELISA and immunohistochemistry to detect intra- and extracellular protein levels of endocytic-related proteins, APP and APP metabolites including β-amyloid (Aβ). Levels of functional endocytosis were quantified using ALEXA 488-conjugated transferrin and flow cytometry as a marker of clathrin-mediated endocytosis (CME). Results: Following depletion of all the isoforms of PICALM by siRNA in H4 cells, levels of intracellular APP, intracellular β-C-terminal fragment (β-CTF) and secreted sAPPβ (APP fragments produced by β-secretase cleavage) were significantly reduced but Aβ40 was not affected. Functional endocytosis was significantly reduced after both PICALM and clathrin depletion, highlighting the importance of PICALM in this process. However, depletion of clathrin did not affect APP but did reduce β-CTF levels. PICALM depletion altered the intracellular distribution of clathrin while clathrin reduction affected the subcellular pattern of PICALM labelling. Both PICALM and clathrin depletion reduced the expression of BACE1 mRNA and PICALM siRNA reduced protein levels. Individual depletion of PICALM isoforms 1 and 2 did not affect APP levels while clathrin depletion had a differential effect on the isoforms, increasing isoform 1 while decreasing isoform 2 expression. Conclusions: The depletion of PICALM in brain-derived cells has significant effects on the processing of APP, probably by reducing CME. In particular, it affects the production of β-CTF which is increasingly considered to be an important mediator in AD independent of Aβ. Thus a decrease in PICALM expression in the brain could be beneficial to slow or prevent the development of AD

    Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial

    Get PDF
    Background Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear. Methods RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047. Findings Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths. Interpretation Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population

    Duration of androgen deprivation therapy with postoperative radiotherapy for prostate cancer: a comparison of long-course versus short-course androgen deprivation therapy in the RADICALS-HD randomised trial

    Get PDF
    Background Previous evidence supports androgen deprivation therapy (ADT) with primary radiotherapy as initial treatment for intermediate-risk and high-risk localised prostate cancer. However, the use and optimal duration of ADT with postoperative radiotherapy after radical prostatectomy remains uncertain. Methods RADICALS-HD was a randomised controlled trial of ADT duration within the RADICALS protocol. Here, we report on the comparison of short-course versus long-course ADT. Key eligibility criteria were indication for radiotherapy after previous radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to add 6 months of ADT (short-course ADT) or 24 months of ADT (long-course ADT) to radiotherapy, using subcutaneous gonadotrophin-releasing hormone analogue (monthly in the short-course ADT group and 3-monthly in the long-course ADT group), daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as metastasis arising from prostate cancer or death from any cause. The comparison had more than 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 75% to 81% (hazard ratio [HR] 0·72). Standard time-to-event analyses were used. Analyses followed intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov , NCT00541047 . Findings Between Jan 30, 2008, and July 7, 2015, 1523 patients (median age 65 years, IQR 60–69) were randomly assigned to receive short-course ADT (n=761) or long-course ADT (n=762) in addition to postoperative radiotherapy at 138 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 8·9 years (7·0–10·0), 313 metastasis-free survival events were reported overall (174 in the short-course ADT group and 139 in the long-course ADT group; HR 0·773 [95% CI 0·612–0·975]; p=0·029). 10-year metastasis-free survival was 71·9% (95% CI 67·6–75·7) in the short-course ADT group and 78·1% (74·2–81·5) in the long-course ADT group. Toxicity of grade 3 or higher was reported for 105 (14%) of 753 participants in the short-course ADT group and 142 (19%) of 757 participants in the long-course ADT group (p=0·025), with no treatment-related deaths. Interpretation Compared with adding 6 months of ADT, adding 24 months of ADT improved metastasis-free survival in people receiving postoperative radiotherapy. For individuals who can accept the additional duration of adverse effects, long-course ADT should be offered with postoperative radiotherapy. Funding Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society

    An approximation for computing reduction in bandwidth requirements using intelligent multiplexers

    Get PDF
    This paper stochastically models a single-node telecommunications system both with and without the use of intelligent multiplexing. Intelligent multiplexers take advantage of the idle periods or silences that occur during the course of speech transmissions to merge (or multiplex) packetized talkspurts from more than one source onto a single channel. This allows for a more efficient use of available bandwidth, thereby reducing the amount of bandwidth required to carry a particular traffic load. Digitizing speech into packets of equal size also allows for compression, further reducing bandwidth needs. By comparing the models for systems both with and without multiplexing, we are able to determine the reduction in bandwidth which may be expected for a particular grade of service (measured by blocking probabilities). A bivariate continuous time Markov chain model for a multiplexer is presented. An approximation is introduced to calculate limiting blocking probabilities much more quickly and for larger systems than is possible by solving a set of linear equations for the bivariate model. The accuracy of the approximation is explored through comparison with the bivariate model; the approximation provides a somewhat conservative estimate of blocking, but is close enough to be used as a tool for the range of relevant values. The approximation is then used to compare blocking probabilities for three different levels of speech activity. Results are shown in tabular form.... Telecommunications, Model, Stochastic telecommunications modelhttp://archive.org/details/approximationfor00hensLieutenant Commander, United States NavyApproved for public release; distribution is unlimited
    corecore