1,721,036 research outputs found
Development of a cost-effectiveness model for optimisation of the screening interval in diabetic retinopathy screening
Full text linkBACKGROUND:
The English NHS Diabetic Eye Screening Programme was established in 2003. Eligible people are invited annually for digital retinal photography screening. Those found to have potentially sight-threatening diabetic retinopathy (STDR) are referred to surveillance clinics or to Hospital Eye Services.
OBJECTIVES:
To determine whether personalised screening intervals are cost-effective.
DESIGN:
Risk factors were identified in Gloucestershire, UK using survival modelling. A probabilistic decision hidden (unobserved) Markov model with a misgrading matrix was developed. This informed estimation of lifetime costs and quality-adjusted life-years (QALYs) in patients without STDR. Two personalised risk stratification models were employed: two screening episodes (SEs) (low, medium or high risk) or one SE with clinical information (low, medium-low, medium-high or high risk). The risk factor models were validated in other populations.
SETTING:
Gloucestershire, Nottinghamshire, South London and East Anglia (all UK).
PARTICIPANTS:
People with diabetes in Gloucestershire with risk stratification model validation using data from Nottinghamshire, South London and East Anglia.
MAIN OUTCOME MEASURES:
Personalised risk-based algorithm for screening interval; cost-effectiveness of different screening intervals.
RESULTS:
Data were obtained in Gloucestershire from 12,790 people with diabetes with known risk factors to derive the risk estimation models, from 15,877 people to inform the uptake of screening and from 17,043 people to inform the health-care resource-usage costs. Two stratification models were developed: one using only results from previous screening events and one using previous screening and some commonly available GP data. Both models were capable of differentiating groups at low and high risk of development of STDR. The rate of progression to STDR was 5 per 1000 person-years (PYs) in the lowest decile of risk and 75 per 1000 PYs in the highest decile. In the absence of personalised risk stratification, the most cost-effective screening interval was to screen all patients every 3 years, with a 46% probability of this being cost-effective at a £30,000 per QALY threshold. Using either risk stratification models, screening patients at low risk every 5 years was the most cost-effective option, with a probability of 99-100% at a £30,000 per QALY threshold. For the medium-risk groups screening every 3 years had a probability of 43-48% while screening high-risk groups every 2 years was cost-effective with a probability of 55-59%.
CONCLUSIONS:
The study found that annual screening of all patients for STDR was not cost-effective. Screening this entire cohort every 3 years was most likely to be cost-effective. When personalised intervals are applied, screening those in our low-risk groups every 5 years was found to be cost-effective. Screening high-risk groups every 2 years further improved the cost-effectiveness of the programme. There was considerable uncertainty in the estimated incremental costs and in the incremental QALYs, particularly with regard to implications of an increasing proportion of maculopathy cases receiving intravitreal injection rather than laser treatment. Future work should focus on improving the understanding of risk, validating in further populations and investigating quality issues in imaging and assessment including the potential for automated image grading
Cost-effectiveness of digital surveillance clinics with optical coherence tomography versus hospital eye service follow-up for patients with screen-positive maculopathy
Full text linkAnnually 2.7 million individuals are offered screening for diabetic retinopathy (DR) in England. Spectral-Domain Optical Coherence Tomography (SD-OCT) has the potential to relieve pressure on NHS services by correctly identifying patients who are screen positive for maculopathy on two-dimensional photography without evidence of clinically significant macular oedema (CSMO), limiting the number of referrals to hospitals. We aim to assess whether the addition of SDOCT imaging in digital surveillance clinics is a cost-effective intervention relative to hospital eye service (HES) follow-up. We used patient-level data from the Gloucestershire Diabetic Eye Screening Service linked to the local digital surveillance programme and HES between 2012 and 2015. A model was used to simulate the progression of individuals with background diabetic retinopathy (R1) and diabetic maculopathy (M1) following DR screening across the clinic pathways over 12 months. Between January 2012 and December 2014, 696 people undergoing DR screening were found to have screen-positive maculopathy in at least one eye for the first time, with a total of 766 eyes identified as having R1M1. The mean annual cost of assessing and surveillance through the SD-OCT clinic pathway was £101 (95% CI: 91-139) as compared with £177 (95%CI: 164-219) under the HES pathway. Surveillance under an SD-OCT clinic generated cost savings of £76 (95% CI: 70-81) per patient. Our analysis shows that SD-OCT surveillance of patients diagnosed as R1M1 at DR screening is not only cost-effective but generates considerable cost savings
Associations of multimorbidity with stroke aetiology, severity, outcome, and long-term prognosis
No full textIn clinical practice today, many patients present with stroke having multiple pre-existing long-term conditions; otherwise known as multimorbidity. Both the prevalence of multimorbidity and the incidence of stroke are closely related to age and, predictably, the prevalence of pre stroke multimorbidity is a high and growing healthcare challenge. Despite this, there remains a dearth of data on the impacts of multimorbidity on outcomes following stroke, which limits the understanding of prognosis and how to best treat such patients.
The overarching aim of this thesis is to provide amongst the first comprehensive investigations into the associations between pre-existing multimorbidity on a range of outcomes following stroke using a modern, population-based stroke incidence study (Oxford Vascular Study).
First, I found that existing research on multimorbidity in stroke has focused on associations with all-cause mortality and functional outcomes, with over a dozen different scales used to quantify multimorbidity. Second, I demonstrated that the Charlson Comorbidity Index performed similarly to the recently developed but more complex Elixhauser Index, and recommend its use as the scale of choice for future studies in stroke. Third, I found that multimorbidity was not associated with stroke severity independent of stroke subtype and was only weakly associated with 90-day outcome after adjustment for confounders. Fourth, I demonstrated multimorbidity was strongly predictive of long-term mortality up to 10-years after stroke, particularly in patients with good predicted early outcome and those at traditionally lower risk (younger age, minor stroke, no pre-morbid disability). Fifth, I combined multimorbidity with age, stroke severity, and pre-morbid disability to demonstrate proof-of concept heat-maps that estimate 5-year absolute risk of post-stroke mortality, which can potentially help decisions for interventions that require multiple years to yield overall benefit. Sixth, I showed that associations between multimorbidity and long-term mortality after stroke were not explained by common serum biomarkers associated with inflammation, thrombosis/atherogenesis, and cardiac/neuronal function or injury. Finally, I concluded by showing that multimorbidity was associated with greater levels of disability and lower quality of life up to 10-years after stroke, but not with higher rates of institutionalisation
Resource costs, health outcomes and cost-effectiveness in stroke care: Evidence from the Oxford Vascular Study
Full text linkIntroduction: Cerebrovascular events are a major cause of mortality, disability and healthcare resource use. Despite this, there is a lack of reliable information on their costs and outcomes, particularly related to transient ischaemic attacks (TIA) and minor stroke. Such information is vital to inform decisions about local and national service provision, and to provide reliable estimates for use in cost-effectiveness analyses. Aims This thesis estimates the costs and outcomes of stroke and TIA using data from a population-based study undertaken in a population of over 91,000 individuals in Oxfordshire (the Oxford Vascular Study – OXVASC). In addition, the thesis aims to estimate the short-term cost-effectiveness of two secondary stroke prevention programmes evaluated in a study nested within OXVASC. Methods: Using multiple methods of case ascertainment, 1,282 patients were identified as having suffered a stroke or TIA, of which 1,199 (723 stroke and 476 TIA) patients consented to the study. Follow-up of patients took place at 1, 6, 12 and 24 months, with data collected on patients’ disability, medication usage, living arrangements, and quality of life. Healthcare resource use information was derived from hospital and primary care records, and priced using published unit costs. Findings: Stroke patients had higher case-fatality rates than TIA patients (15% vs. 1%; p<0.001), with 5-year life expectancy being one year longer for TIA patients. For stroke and TIA survivors, the risk of disability remained higher, at around 30% at each of the four follow-ups, than at baseline (17%; p<0.001 for all follow-ups). After standardising for age and gender, average quality of life for stroke and TIA patients combined was significantly lower than English population norms (p<0.001 for all follow-ups). However, when quality of life was compared to population norms by event type, quality of life differences between TIA patients and English population norms no longer remained statistically significant. Important predictors of quality of life included event severity, baseline disability and recurrent vascular events. Total costs were considerably higher 1-year after the initial stroke or TIA than for the year preceding it and, except for day cases, increases were observed for all resource-use categories. Five years after the index event, stroke patients incurred costs of £16,923 (95% CI: 15,149 to 18,858) per patient, significantly higher than those incurred by TIA patients, at £13,904 (95% CI: 11,488 to 16,657; p=0.019). In multivariate analyses, event severity was found to be a significant predictor of inpatient care resource use and costs, as were the presence of recurrent vascular events, especially stroke and coronary events. For non-hospitalised patients, results showed that urgent outpatient specialist assessment and treatment reduced the 90-day risk of fatal or disabling stroke (0.4% vs. 5%, p<0.001) compared with less urgent assessment and treatment. In terms of resource usage, patients who were assessed and treated urgently had lower recurrent stroke hospitalisation (2% vs. 8%; p=0.001), and reduced overall number of days in hospital (average reduction of 4 days; p=0.017). These reductions in hospital resource usage generated savings of £643 per patient assessed and treated urgently in an outpatient clinic (p=0.028). Conclusion: Despite the impact of stroke on death, disability and healthcare resource use, there is a lack of reliable information on costs and outcomes, especially for TIA and minor stroke. Through the use of a population-based study, the gold-standard study design when assessing the incidence and outcomes of TIA and stroke, this thesis provides healthcare decision makers and researchers with a wealth of data on the resource use patterns, costs and outcomes of TIA and stroke patients, and their main predictors
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Health-related quality of life and healthcare costs of symptoms and cardiovascular disease events in patients with atrial fibrillation: a longitudinal analysis of 27 countries from the EURObservational Research Programme on Atrial Fibrillation general long-term registry
Full text linkAims: We examine the effects of symptoms and cardiovascular disease (CVD) events on health-related quality of life (HRQOL) and healthcare costs in a European population with atrial fibrillation (AF). Methods and results: In the EURObservational Research Programme on AF long-term general registry, AF patients from 250 centres in 27 European countries were enrolled and followed for 2 years. We used fixed effects models to estimate the association of symptoms and CVD events on HRQOL and annual healthcare costs. We found significant decrements in HRQOL in AF patients in whom ST-segment elevation myocardial infarction (STEMI) [−0.075 (95% confidence interval −0.144, −0.006)], angina or non-ST-elevation myocardial infarction (NSTEMI) [−0.037 (−0.071, −0.003)], new-onset/worsening heart failure [−0.064 (−0.088, −0.039)], bleeding events [−0.031 (−0.059, −0.003)], thromboembolic events [−0.071 (−0.115, −0.027)], mild symptoms [0.037 (−0.048, −0.026)], or severe/disabling symptoms [−0.090 (−0.108, −0.072)] occurred during the follow-up. During follow-up, annual healthcare costs were associated with an increase of €11 718 (€8497, €14 939) in patients with STEMI, €5823 (€4757, €6889) in patients with angina/NSTEMI, €3689 (€3219, €4158) in patients with new-onset or worsening heart failure, €3792 (€3315, €4270) in patients with bleeding events, and €3182 (€2483, €3881) in patients with thromboembolic events, compared with AF patients without these events. Healthcare costs were primarily driven by inpatient costs. There were no significant differences in HRQOL or healthcare resource use between EU regions or by sex. Conclusion: Symptoms and CVD events are associated with a high burden on AF patients and healthcare systems throughout Europe
The National Eye Survey of Trinidad and Tobago
Full text linkBackground: Avoidable vision impairment (VI, Snellen acuity
Study design: A national, population-based, cross-sectional survey of the non-institutionalized population aged 40 years and above in Trinidad and Tobago in 2013/2014, used random multistage cluster sampling with probability proportional to size methods.
Methods: In each of 120 clusters, 35 eligible adults were enumerated. In community screening, the presenting uniocular distance and binocular near visual acuity was measured and basic demographic, socioeconomic and health data collected. All participants were invited to regional clinics for more detailed interview and comprehensive ocular and medical examination with imaging. Interviews included assessment of health service utilization, costs, and health-related quality of life, using the EQ-5D instrument.
Results: From 3556 households, 4263 eligible adults were identified, of whom 84.2% (n=3589) participated in community screening, and 65.4% (n=2790) in regional clinics. After adjustment for the multilevel, clustered study design and non-response rate, and weighting by the age, sex and municipality of participants, the prevalence of presenting VI was 11.88 % (95% confidence interval (CI) 10.88-12.97, n = 468 / 3580), including blindness in 0.73% (95% CI 0.48 to 0.97, n = 31). The leading causes of blindness were glaucoma (31.7% 95% CI 18.7 to 44.8), cataract (28.8%, 95 % CI 12.6 to 45.1), and diabetic retinopathy (19.1%, 95 % CI 4.2 to 34.0). The leading cause of presenting distance VI was uncorrected refractive error (47.4%, 95% CI 43.4 to 51.3), and 86.1% (95% CI 82.88-88.81) of distance VI was potentially avoidable. A further 22.3% (95% CI 20.7 to 23.8) had uncorrected near VI resulting from presbyopia. In total, within Trinidad and Tobago there were an estimated 185,273 (95% CI 167,337 to 203,048) people aged 40 years and above with near or distance VI, and 176,323 cases were potentially avoidable. Significant independent associations with presenting distance VI included increasing age (p
Conclusions: The National Eye Survey of Trinidad and Tobago obtained original population-based data on the magnitude, causes and risk factors for avoidable VI in Trinidad and Tobago, and identified significant associated economic and quality of life impact. This evidence-base provides the foundation for the development of a national eye care strategy. </p
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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