53 research outputs found

    A prospective observational study of treatment practice patterns in acute coronary syndrome patients undergoing percutaneous coronary intervention in Europe

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    SummaryBackgroundThe AntiPlatelet Therapy Observational Registry (APTOR) was a prospective observational study of acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) in France, Spain, and the UK.AimsTo evaluate patterns of ACS healthcare use, focusing on APTOR results from France.MethodsConsecutive presenting ACS patients requiring PCI were recruited between January and August 2007. Treatments and outcomes were recorded from the qualifying ACS event to 12months follow-up.ResultsIn France, qualifying diagnosis was unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI) in 255(53%) patients and ST-segment elevation myocardial infarction (STEMI) in 228(47%)patients. Ninety-six percent underwent PCI with stent implantation. Drug eluting stents were used less frequently in France(22%) than Spain (54%) or the UK (42%). In France, antiplatelets were more frequently received in the ambulance (21%); a 200–299mg aspirin-loading dose was most frequently received (50%) and more than a third of patients received a clopidogrel-loading dose of over300mg (34%). At 12months in France, 86% were still receiving aspirin, 75% clopidogrel, and 73% combination treatment.ConclusionThere was considerable country-variation in ACS management. These results provide a benchmark of physician practice to compare with guidelines

    Factors associated with long-term impact on informal caregivers during Alzheimer's disease dementia progression: 36-month results from GERAS

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    OBJECTIVE: To identify, in caregivers of patients with Alzheimer's disease (AD) dementia, factors associated with subjective (personal, physical, emotional, and social) and objective (informal caregiver time and costs) caregiver burden. DESIGN: Prospective longitudinal European observational study: post-hoc analysis. SETTING: Clinic. PARTICIPANTS: Community-dwelling patients in France and Germany aged ≥ 55 years (n = 969) with probable AD and their informal caregivers. MEASUREMENTS: Mini-Mental State Examination (MMSE), Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL), 12-item Neuropsychiatric Inventory (NPI-12), Zarit Burden Interview (ZBI), informal caregiver basic and instrumental ADL hours (Resource Utilization in Dementia instrument), and informal caregiver costs. Mixed-effect models of repeated measures (MMRM) were run, including baseline and time-dependent covariates (change from baseline [CFB] to 18 months in MMSE, ADCS-ADL, and NPI-12 scores) associated with CFB in ZBI score/informal caregiver time over 36 months (analyzed using linear regression models) and informal caregiver costs over 36 months (analyzed using generalized linear models). RESULTS: Greater decline in patient function (ADCS-ADL) over 18 months was associated with increased subjective caregiver burden (ZBI), hours, and costs over 36 months. Increased behavioral problems (NPI-12) over 18 months also negatively impacted ZBI. Cognitive decline (MMSE) over 18 months did not affect change in caregiver burden. CONCLUSIONS: Long-term informal caregiver burden was driven by worsening functional abilities and behavioral symptoms but not cognitive decline, over 18 months in community-dwelling patients with AD dementia. Identifying the drivers of caregiver burden could highlight areas in which interventions may benefit both caregivers and patients

    Excess Costs Associated with Possible Misdiagnosis of Alzheimer's Disease Among Patients with Vascular Dementia in a UK CPRD Population

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    The authors would like to acknowledge Julie von Ziegenweidt and Annie Burden (Research in Real Life, UK) for assistance with processing and interpretation of CPRD data, and Gillian Gummer and Caroline Spencer (Rx Communications, Mold, UK) for medical writing assistance with the preparation of this article, funded by Eli Lilly and Company. Authors’ disclosures available online (http://j-alz. com/manuscript-disclosures/15-0685r2).Peer reviewedPublisher PD

    How to deal with missing longitudinal data in cost of illness analysis in Alzheimer’s disease—suggestions from the GERAS observational study

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    BACKGROUND: Missing data are a common problem in prospective studies with a long follow-up, and the volume, pattern and reasons for missing data may be relevant when estimating the cost of illness. We aimed to evaluate the effects of different methods for dealing with missing longitudinal cost data and for costing caregiver time on total societal costs in Alzheimer's disease (AD). METHODS: GERAS is an 18-month observational study of costs associated with AD. Total societal costs included patient health and social care costs, and caregiver health and informal care costs. Missing data were classified as missing completely at random (MCAR), missing at random (MAR) or missing not at random (MNAR). Simulation datasets were generated from baseline data with 10-40 % missing total cost data for each missing data mechanism. Datasets were also simulated to reflect the missing cost data pattern at 18 months using MAR and MNAR assumptions. Naïve and multiple imputation (MI) methods were applied to each dataset and results compared with complete GERAS 18-month cost data. Opportunity and replacement cost approaches were used for caregiver time, which was costed with and without supervision included and with time for working caregivers only being costed. RESULTS: Total costs were available for 99.4 % of 1497 patients at baseline. For MCAR datasets, naïve methods performed as well as MI methods. For MAR, MI methods performed better than naïve methods. All imputation approaches were poor for MNAR data. For all approaches, percentage bias increased with missing data volume. For datasets reflecting 18-month patterns, a combination of imputation methods provided more accurate cost estimates (e.g. bias: -1 % vs -6 % for single MI method), although different approaches to costing caregiver time had a greater impact on estimated costs (29-43 % increase over base case estimate). CONCLUSIONS: Methods used to impute missing cost data in AD will impact on accuracy of cost estimates although varying approaches to costing informal caregiver time has the greatest impact on total costs. Tailoring imputation methods to the reason for missing data will further our understanding of the best analytical approach for studies involving cost outcomes

    The 'RCT augmentation': a novel simulation method to add patient heterogeneity into phase III trials.

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    BACKGROUND: Phase III randomized controlled trials (RCT) typically exclude certain patient subgroups, thereby potentially jeopardizing estimation of a drug's effects when prescribed to wider populations and under routine care ('effectiveness'). Conversely, enrolling heterogeneous populations in RCTs can increase endpoint variability and compromise detection of a drug's effect. We developed the 'RCT augmentation' method to quantitatively support RCT design in the identification of exclusion criteria to relax to address both of these considerations. In the present manuscript, we describe the method and a case study in schizophrenia. METHODS: We applied typical RCT exclusion criteria in a real-world dataset (cohort) of schizophrenia patients to define the 'RCT population' subgroup, and assessed the impact of re-including each of the following patient subgroups: (1) illness duration 1-3 years; (2) suicide attempt; (3) alcohol abuse; (4) substance abuse; and (5) private practice management. Predictive models were built using data from different 'augmented RCT populations' (i.e., subgroups where patients with one or two of such characteristics were re-included) to estimate the absolute effectiveness of the two most prevalent antipsychotics against real-world results from the entire cohort. Concurrently, the impact on RCT results of relaxing exclusion criteria was evaluated by calculating the comparative efficacy of those two antipsychotics in virtual RCTs drawing on different 'augmented RCT populations'. RESULTS: Data from the 'RCT population', which was defined with typical exclusion criteria, allowed for a prediction of effectiveness with a bias < 2% and mean squared error (MSE) = 5.8-6.8%. Compared to this typical RCT, RCTs using augmented populations provided improved effectiveness predictions (bias < 2%, MSE = 5.3-6.7%), while returning more variable comparative effects. The impact of augmentation depended on the exclusion criterion relaxed. Furthermore, half of the benefit of relaxing each criterion was gained from re-including the first 10-20% of patients with the corresponding real-world characteristic. CONCLUSIONS: Simulating the inclusion of real-world subpopulations into an RCT before running it allows for quantification of the impact of each re-inclusion upon effect detection (statistical power) and generalizability of trial results, thereby explicating this trade-off and enabling a controlled increase in population heterogeneity in the RCT design

    What drives country differences in cost of Alzheimer's Disease? An explanation from resource use in the GERAS Study

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    BACKGROUND: Country differences in resource use and costs of Alzheimer's disease (AD) may be driven by differences in health care systems and resource availability. OBJECTIVE: To compare country resource utilization drivers of societal costs for AD dementia over 18 months. METHODS: GERAS is an observational study in France (n = 419), Germany (n = 550), and the UK (n = 526). Resource use of AD patients and caregivers contributing to >1% of total societal costs (year 2010) was assessed for country differences, adjusting for participant characteristics. RESULTS: Mean 18-month societal costs per patient were France ¿33,339, Germany ¿38,197, and UK ¿37,899 (£32,501). Caregiver time spent on basic and instrumental activities of daily living (ADL) contributed the most to societal costs (54% France, 64% Germany, 65% UK). Caregivers in France spent less time on ADL than UK caregivers and missed fewer work days than in other countries. Compared with other countries, patients in France used more community care services overall and were more likely to use home aid. Patients in Germany were least likely to use temporary accommodation or to be institutionalized at 18 months. UK caregivers spent the most time on instrumental ADL, UK patients used fewest outpatient resources, and UK patients/caregivers were most likely to receive financial support. CONCLUSION: Caregiver time on ADL contributed the most to societal costs and differed across countries, possibly due to use of community care services and institutionalization. Other resources had different patterns of use across countries, reflecting country-specific health and social care systems

    Complementary pre-screening strategies to uncover hidden prodromal and mild Alzheimer's disease : Results from the MOPEAD project

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    The Models of Patient Engagement for Alzheimer's Disease (MOPEAD) project was conceived to explore innovative complementary strategies to uncover hidden prodromal and mild Alzheimer's disease (AD) dementia cases and to raise awareness both in the general public and among health professionals about the importance of early diagnosis. Four different strategies or RUNs were used: (a) a web-based (WB) prescreening tool, (2) an open house initiative (OHI), (3) a primary care-based protocol for early detection of cognitive decline (PC), and (4) a tertiary care-based pre-screening at diabetologist clinics (DC). A total of 1129 patients at high risk of having prodromal AD or dementia were identified of 2847 pre-screened individuals (39.7%). The corresponding proportion for the different initiatives were 36.8% (WB), 35.6% (OHI), 44.4% (PC), and 58.3% (DC). These four complementary pre-screening strategies were useful for identifying individuals at high risk of having prodromal or mild AD

    Test-retest and between-site reliability in a multicenter fMRI study

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    In the present report, estimates of test–retest and between-site reliability of fMRI assessments were produced in the context of a multicenter fMRI reliability study (FBIRN Phase 1, www.nbirn.net). Five subjects were scanned on 10 MRI scanners on two occasions. The fMRI task was a simple block design sensorimotor task. The impulse response functions to the stimulation block were derived using an FIR-deconvolution analysis with FMRISTAT. Six functionally-derived ROIs covering the visual, auditory and motor cortices, created from a prior analysis, were used. Two dependent variables were compared: percent signal change and contrast-to-noise-ratio. Reliability was assessed with intraclass correlation coefficients derived from a variance components analysis. Test–retest reliability was high, but initially, between-site reliability was low, indicating a strong contribution from site and site-by-subject variance. However, a number of factors that can markedly improve between-site reliability were uncovered, including increasing the size of the ROIs, adjusting for smoothness differences, and inclusion of additional runs. By employing multiple steps, between-site reliability for 3T scanners was increased by 123%. Dropping one site at a time and assessing reliability can be a useful method of assessing the sensitivity of the results to particular sites. These findings should provide guidance to others on the best practices for future multicenter studies
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