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1.
Br J Ophthalmol ; 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336459

RESUMO

BACKGROUND/AIMS: Advanced primary open angle glaucoma (POAG) is a lifelong condition. The aim of this study is to compare medical treatment against trabeculectomy for patients presenting with advanced POAG using an economic evaluation decision model. METHODS: A Markov model was used to compare the two treatments, medical treatment versus trabeculectomy for the management of advanced POAG, in terms of costs and quality-adjusted life-years (QALYs). The uncertainty surrounding the model findings was assessed using probabilistic sensitivity analysis and deterministic analysis. Data for the model came from Treatment of Advanced Glaucoma Study supplemented with data from the literature. The main outcomes of the model presented in terms of Incremental costs and QALYs based on responses to the EQ-5D-5L, Health Utilities Index-3 and a Glaucoma Utility Index. RESULTS: In the base-case analysis (lifetime horizon and EQ-5D-5L measure), participants receiving trabeculectomy had on average, an additional cost of £2687, an additional 0.28 QALYs and an incremental cost per QALY of £9679 compared with medical treatment. There was a 73% likelihood of trabeculectomy being considered cost-effective when society was willing to pay £20 000 for a QALY. Over shorter time horizons, the incremental cost per QALY gained from trabeculectomy compared with medical treatment was higher (47 663) for a 2-year time horizon. Our results are robust to changes in the key assumptions and input parameters values. CONCLUSION: In patients presenting with advanced POAG, trabeculectomy has a higher probability of being cost-effective over a patient's lifetime compared with medical treatment.

2.
BMJ Open ; 13(10): e073975, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37793921

RESUMO

INTRODUCTION: Angle-closure is responsible for half of all glaucoma blindness globally. Patients with suspected glaucoma require assessment of the drainage angle by an experienced clinician. The goal of this study is to evaluate the diagnostic performance and cost-effectiveness of two non-contact tests, anterior segment OCT (Optical Coherence Tomography) (AS-OCT) and limbal anterior chamber depth for patients referred to hospital with suspected angle closure compared with gonioscopy by ophthalmologist. METHODS AND ANALYSIS: Study design: prospective, multicentre, cross-sectional diagnostic accuracy study. INCLUSION CRITERIA: adults referred from community optometry to hospital with suspected angle closure. PRIMARY OUTCOME: Sensitivity and specificity. SECONDARY OUTCOMES: Positive/negative likelihood ratios, concordance, cost-effectiveness, proportion of patients requiring subsequent clinical assessment by ophthalmologist. SAMPLE SIZE: 600 individuals who have been referred with suspected angle closure from primary care (community optometry). We will have a 95% probability of detecting the true sensitivity of either test to within ±3.5% based on a sensitivity of 90%. The study would also have a 95% probability of detecting the true specificity of either test to within ±5%, assuming a specificity of 75%. ETHICS AND DISSEMINATION: Ethical Review Board approval was obtained. REC reference: 22/LO/0885. Our findings will be disseminated to those involved in eye care services. We will have a knowledge exchange event at the end of the study, published via the Health Technology Assessment web page and in specialist journals. The results will be presented at professional conferences and directly to patients via patient group meetings and the Glaucoma UK charity. TRIAL REGISTRATION NUMBER: ISRCTN15115867.


Assuntos
Glaucoma de Ângulo Fechado , Glaucoma , Adulto , Humanos , Glaucoma de Ângulo Fechado/diagnóstico , Estudos Transversais , Estudos Prospectivos , Pressão Intraocular , Tomografia de Coerência Óptica/métodos , Estudos Multicêntricos como Assunto
3.
Br J Ophthalmol ; 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35882513

RESUMO

SYNOPSIS: Advanced glaucoma is associated with sight loss. This within-trial economic evaluation compares medical and surgical management strategies. At 2 years, medication appears more cost-effective though longitudinal outcomes are an important subject in future research. BACKGROUND/AIMS: Open angle glaucoma (OAG) is a progressive optic neuropathy. Approximately 25% of newly diagnosed patients with OAG present with advanced disease in at least one eye. The vision loss associated with OAG can lead to significant impacts on vision, quality of life and health care resources. The Treatment of Advanced Glaucoma Study is a randomised controlled trial comparing the effectiveness of primary surgical and medical management for newly diagnosed advanced patients with OAG. An economic evaluation was carried out to understand the costs and benefits of each strategy. METHODS: A cost utility analysis was carried out from a National Health Service perspective over a 2-year time horizon inclusive of patient costs. The primary outcome was patient health-related quality of life measured by the EQ-5D-5L, Health Utilities Index 3 (HUI3) and Glaucoma Utility Index (GUI). Results were expressed as incremental cost per QALY gained. RESULTS: Trabeculectomy was associated with higher costs and greater effect, the EQ-5D-5L results have an incremental cost per QALY of £45,456. The likelihood of surgery being cost-effective at a £20, 000, £30,000 and £50,000 QALY threshold is 0%, 12% and 56%, respectively. The results for the HUI3, GUI and inclusion of patient costs do not change the conclusions of the study. CONCLUSION: This is the first study to evaluate management strategies for those presenting with advanced glaucoma. At a 2-year time horizon, medication is the more cost-effective approach for managing glaucoma. Future research can focus on the costs and benefits of the treatments over a longer time horizon.

4.
Health Technol Assess ; 25(72): 1-158, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34854808

RESUMO

BACKGROUND: Patients diagnosed with advanced primary open-angle glaucoma are at a high risk of lifetime blindness. Uncertainty exists about whether primary medical management (glaucoma eye drops) or primary surgical treatment (augmented trabeculectomy) provide the best and safest patient outcomes. OBJECTIVES: To compare primary medical management with primary surgical treatment (augmented trabeculectomy) in patients with primary open-angle glaucoma presenting with advanced disease in terms of health-related quality of life, clinical effectiveness, safety and cost-effectiveness. DESIGN: This was a two-arm, parallel, multicentre, pragmatic randomised controlled trial. SETTING: Secondary care eye services. PARTICIPANTS: Adult patients presenting with advanced primary open-angle glaucoma in at least one eye, as defined by the Hodapp-Parrish-Anderson classification of severe glaucoma. INTERVENTION: Primary medical treatment - escalating medical management with glaucoma eye drops. Primary trabeculectomy treatment - trabeculectomy augmented with mitomycin C. MAIN OUTCOME MEASURES: The primary outcome was health-related quality of life measured with the Visual Function Questionnaire-25 at 2 years post randomisation. Secondary outcomes were mean intraocular pressure; EQ-5D-5L; Health Utilities Index 3; Glaucoma Utility Index; cost and cost-effectiveness; generic, vision-specific and disease-specific health-related quality of life; clinical effectiveness; and safety. RESULTS: A total of 453 participants were recruited. The mean age of the participants was 67 years (standard deviation 12 years) in the trabeculectomy arm and 68 years (standard deviation 12 years) in the medical management arm. Over 65% of participants were male and more than 80% were white. At 24 months, the mean difference in Visual Function Questionnaire-25 score was 1.06 (95% confidence interval -1.32 to 3.43; p = 0.383). There was no evidence of a difference between arms in the EQ-5D-5L score, the Health Utilities Index or the Glaucoma Utility Index. At 24 months, the mean intraocular pressure was 12.40 mmHg in the trabeculectomy arm and 15.07 mmHg in the medical management arm (mean difference -2.75 mmHg, 95% confidence interval -3.84 to -1.66 mmHg; p < 0.001). Fewer types of glaucoma eye drops were required in the trabeculectomy arm. LogMAR visual acuity was slightly better in the medical management arm (mean difference 0.07, 95% confidence interval 0.02 to 0.11; p = 0.006) than in the trabeculectomy arm. There was no evidence of difference in safety between the two arms. A discrete choice experiment updated the utility values for the Glaucoma Utility Index. The within-trial economic analysis found a small increase in the mean EQ-5D-5L score (0.04) and that trabeculectomy has a higher probability of being cost-effective than medical management. The incremental cost of trabeculectomy per quality-adjusted life-year was £45,456. Therefore, at 2 years, surgery is unlikely to be considered cost-effective at a threshold of £20,000 per quality-adjusted life-year. When extrapolated over a patient's lifetime in a model-based analysis, trabeculectomy, compared with medical treatment, was associated with higher costs (average £2687), a larger number of quality-adjusted life-years (average 0.28) and higher incremental cost per quality-adjusted life-year gained (average £9679). The likelihood of trabeculectomy being cost-effective at a willingness-to-pay threshold of £20,000 per quality-adjusted life year gained was 73%. CONCLUSIONS: Our results suggested that there was no difference between treatment arms in health-related quality of life, as measured with the Visual Function Questionnaire-25 at 24 months. Intraocular pressure was better controlled in the trabeculectomy arm, and this may reduce visual field progression. Modelling over the patient's lifetime suggests that trabeculectomy may be cost-effective over the range of values of society's willingness to pay for a quality-adjusted life-year. FUTURE WORK: Further follow-up of participants will allow us to estimate the long-term differences of disease progression, patient experience and cost-effectiveness. TRIAL REGISTRATION: Current Controlled Trials ISRCTN56878850. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 72. See the NIHR Journals Library website for further project information.


Glaucoma is an eye condition in which the intraocular pressure is too high, causing damage to the optic nerve and loss of vision. Patients with severe vision loss at diagnosis are the most at risk of blindness in their lifetime. Lowering pressure in the eye is the only way to prevent further vision loss. Two treatments to lower pressure are commonly used: using eye drops or having an operation known as a trabeculectomy. In England, Wales and Northern Ireland, the National Institute for Health and Care Excellence recommends surgery as the first treatment. However, we do not know which treatment is best for preventing vision loss or which is safest, has the best patient experience or provides the best value for money for the NHS. Therefore, surgery is not usually carried out in the first instance and patients start with eye drops instead. This study compared whether starting treatment with eye drops affected the quality of life of patients with advanced glaucoma more or less than starting treatment with trabeculectomy. We also investigated if initial treatment with surgery and initial treatment with eye drops were equally good at controlling pressure and were equally safe, and how much each treatment cost the NHS. Every patient had an equal chance of starting treatment with surgery or eye drops and they participated in the study for 2 years. We found that quality of life was similar regardless of treatment. Those starting with surgery had lower pressure and needed far fewer types of eye drops than those starting with eye drops. Thirty-nine patients in the eye drop arm required surgery to control their glaucoma. Initial treatment with eye drops was cheaper over 2 years' follow-up. Our study suggests that, over a 2-year period, having surgery in the first instance lowers intraocular pressure more than eye drops and is equally as safe as eye drops. Although eye drops are a cheaper treatment option for the NHS, if the effects of surgery on intraocular pressure are lasting, then the increased cost may be justified.


Assuntos
Glaucoma de Ângulo Aberto , Glaucoma , Trabeculectomia , Idoso , Análise Custo-Benefício , Feminino , Glaucoma de Ângulo Aberto/tratamento farmacológico , Glaucoma de Ângulo Aberto/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Soluções Oftálmicas , Qualidade de Vida , Anos de Vida Ajustados por Qualidade de Vida
5.
Natl Sci Rev ; 8(2): nwaa145, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34691569

RESUMO

Resolving regional carbon budgets is critical for informing land-based mitigation policy. For nine regions covering nearly the whole globe, we collected inventory estimates of carbon-stock changes complemented by satellite estimates of biomass changes where inventory data are missing. The net land-atmospheric carbon exchange (NEE) was calculated by taking the sum of the carbon-stock change and lateral carbon fluxes from crop and wood trade, and riverine-carbon export to the ocean. Summing up NEE from all regions, we obtained a global 'bottom-up' NEE for net land anthropogenic CO2 uptake of -2.2 ± 0.6 PgC yr-1 consistent with the independent top-down NEE from the global atmospheric carbon budget during 2000-2009. This estimate is so far the most comprehensive global bottom-up carbon budget accounting, which set up an important milestone for global carbon-cycle studies. By decomposing NEE into component fluxes, we found that global soil heterotrophic respiration amounts to a source of CO2 of 39 PgC yr-1 with an interquartile of 33-46 PgC yr-1-a much smaller portion of net primary productivity than previously reported.

6.
BMJ ; 373: n1014, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980505

RESUMO

OBJECTIVE: To determine whether primary trabeculectomy or primary medical treatment produces better outcomes in term of quality of life, clinical effectiveness, and safety in patients presenting with advanced glaucoma. DESIGN: Pragmatic multicentre randomised controlled trial. SETTING: 27 secondary care glaucoma departments in the UK. PARTICIPANTS: 453 adults presenting with newly diagnosed advanced open angle glaucoma in at least one eye (Hodapp classification) between 3 June 2014 and 31 May 2017. INTERVENTIONS: Mitomycin C augmented trabeculectomy (n=227) and escalating medical management with intraocular pressure reducing drops (n=226) MAIN OUTCOME MEASURES: Primary outcome: vision specific quality of life measured with Visual Function Questionnaire-25 (VFQ-25) at 24 months. SECONDARY OUTCOMES: general health status, glaucoma related quality of life, clinical effectiveness (intraocular pressure, visual field, visual acuity), and safety. RESULTS: At 24 months, the mean VFQ-25 scores in the trabeculectomy and medical arms were 85.4 (SD 13.8) and 84.5 (16.3), respectively (mean difference 1.06, 95% confidence interval -1.32 to 3.43; P=0.38). Mean intraocular pressure was 12.4 (SD 4.7) mm Hg for trabeculectomy and 15.1 (4.8) mm Hg for medical management (mean difference -2.8 (-3.8 to -1.7) mm Hg; P<0.001). Adverse events occurred in 88 (39%) patients in the trabeculectomy arm and 100 (44%) in the medical management arm (relative risk 0.88, 95% confidence interval 0.66 to 1.17; P=0.37). Serious side effects were rare. CONCLUSION: Primary trabeculectomy had similar quality of life and safety outcomes and achieved a lower intraocular pressure compared with primary medication. TRIAL REGISTRATION: Health Technology Assessment (NIHR-HTA) Programme (project number: 12/35/38). ISRCTN registry: ISRCTN56878850.


Assuntos
Glaucoma de Ângulo Aberto/cirurgia , Qualidade de Vida , Trabeculectomia/estatística & dados numéricos , Idoso , Feminino , Glaucoma de Ângulo Aberto/psicologia , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Trabeculectomia/psicologia , Reino Unido , Acuidade Visual
8.
Am J Ophthalmol ; 194: 153-162, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30053474

RESUMO

PURPOSE: To evaluate the standards of harm reporting for glaucoma surgical trials and to develop a classification system for reporting surgical complication severity. DESIGN: Systematic review and Delphi consensus method. METHODS: Systematic review of glaucoma surgical trials published from January 2010 until July 2017 with a quality assessment against the CONSORT checklist for harm. A Delphi method was employed to generate consensus grading (interquartile range ≤ 2) among international glaucoma experts (n = 43) on severity of glaucoma surgical complications, and specifically for trabeculectomy and aqueous shunt complications, from 1 (no clinical significance) to 10 (most severe complication). RESULTS: Forty-seven studies were eligible. The items of the CONSORT checklist for harm that were most frequently missing were use of a validated instrument to report severity (0%), withdrawals due to harm, and subgroup analyses, both reported in 3 publications (6.4%). Most glaucoma experts participating in the Delphi process (80%) completed the second round, and consensus was achieved for all but 1 complication. The least severe complications (graded 2) were "transient loss of vision," "early low intraocular pressure," "choroidal detachment anterior to equator," "small layered hyphema < 1 mm," and "increased lens opacity not clinically significant." The most severe complications (graded 10) were "endophthalmitis" and "permanent severe loss of vision (hand movements or worse)." CONCLUSIONS: Glaucoma surgical randomized controlled trials report frequency of complications, but their severity is rarely reported. The quality of harm reporting is poor. We propose the use of a newly developed system of classification for assessing the severity of surgical complications based on consensus.


Assuntos
Implantes para Drenagem de Glaucoma , Glaucoma/cirurgia , Complicações Pós-Operatórias/classificação , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Gestão de Riscos/normas , Trabeculectomia , Consenso , Confiabilidade dos Dados , Interpretação Estatística de Dados , Técnica Delphi , Humanos , Pressão Intraocular , Guias de Prática Clínica como Assunto
9.
Br J Ophthalmol ; 102(7): 922-928, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29074496

RESUMO

BACKGROUND: Presentation with advanced glaucoma is the major risk factor for lifetime blindness. Effective intervention at diagnosis is expected to minimise risk of further visual loss in this group of patients. AIM: To compare clinical and cost-effectiveness of primary medical management compared with primary surgery for people presenting with advanced open-angle glaucoma (OAG). METHODS: Design: A prospective, pragmatic multicentre randomised controlled trial (RCT). SETTING: Twenty-seven UK hospital eye services. PARTICIPANTS: Four hundred and forty patients presenting with advanced OAG, according to the Hodapp-Parish-Anderson classification of visual field loss. INTERVENTION: Participants will be randomised to medical treatment or augmented trabeculectomy (1:1 allocation minimised by centre and presence of advanced disease in both eyes). MAIN OUTCOME MEASURES: The primary outcome is vision-related quality of life measured by the National Eye Institute-Visual Function Questionnaire-25 at 24 months. Secondary outcomes include generic EQ-5D-5L, Health Utility Index-3 and glaucoma-related health status (Glaucoma Utility Index), patient experience, visual field measured by mean deviation value, logarithm of the mean angle of resolution visual acuity, intraocular pressure, adverse events, standards for driving and eligibility for blind certification. Incremental cost per quality-adjusted life-year (QALY) based on EQ-5D-5L and glaucoma profile instrument will be estimated. RESULTS: The study will report the comparative effectiveness and cost-effectiveness of medical treatment against augmented trabeculectomy in patients presenting with advanced glaucoma in terms of patient-reported health and visual function, clinical outcomes and incremental cost per QALY at 2 years. CONCLUSIONS: Treatment of Advanced Glaucoma Study will be the first RCT reporting outcomes from the perspective of those with advanced glaucoma. TRIAL REGISTRATION NUMBER: ISRCTN56878850, Pre-results.


Assuntos
Anti-Hipertensivos/uso terapêutico , Glaucoma de Ângulo Aberto/tratamento farmacológico , Glaucoma de Ângulo Aberto/cirurgia , Trabeculectomia/métodos , Idoso , Anti-Hipertensivos/economia , Análise Custo-Benefício , Feminino , Glaucoma de Ângulo Aberto/economia , Glaucoma de Ângulo Aberto/fisiopatologia , Nível de Saúde , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Anos de Vida Ajustados por Qualidade de Vida , Projetos de Pesquisa , Perfil de Impacto da Doença , Trabeculectomia/economia , Resultado do Tratamento , Acuidade Visual/fisiologia , Campos Visuais/fisiologia
10.
Br J Sociol ; 69(1): 44-66, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28510267

RESUMO

British sociologists have long been interested in youth sub-cultures. However British sociologists have tended to focus on working class subcultures and avoided engagement with exclusive sub-cultures of elite social groups. This article seeks to attend to this gap by examining the subculture of a British elite: ex-public school students at select universities in the UK in the twenty-first century. This group consists of a relatively small group of young adults, aged between 18 and 23, who attended public schools, especially one of the nine Clarendon schools (Eton, Winchester, Westminster, St. Paul's, Merchant Taylor's, Shrewsbury, Rugby, Harrow and Charterhouse), and were students at a selective group of British universities, primarily Oxford and Cambridge, Durham, Bristol, Exeter, Bath, Manchester, St Andrews and Edinburgh. The article examines the way in which this group has reconfigured and re-constituted itself in the face of globalizing challenges. Specifically, it examines the way in which participation of ex-public school students in events run by and under the patronage of the high street retailing company, Jack Wills, has played a galvanising role for this group in the last decade. The Jack Wills crowd is an example of how some young adults form exclusive social networks and reproduce prevailing forms of privilege. The social networks built around the Jack Wills subculture is likely to provide them with advantages in the job market through a prodigious network of connections and patrons. The Jack Wills subculture potentially contributions to the socio-economic reproduction of the higher professional middle classes.


Assuntos
Classe Social , Rede Social , Estudantes , Universidades , Adolescente , Adulto , Emprego , Humanos , Setor Público , Instituições Acadêmicas , Fatores Socioeconômicos , Sociologia , Esportes , Reino Unido , Adulto Jovem
11.
Nature ; 544(7651): S21-S23, 2017 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-28445450

Assuntos
Agricultura/métodos , Agricultura/tendências , Automação/métodos , Tecnologia de Sensoriamento Remoto/métodos , Robótica/métodos , Matadouros , Agricultura/instrumentação , Agroquímicos/efeitos adversos , Agroquímicos/economia , Agroquímicos/provisão & distribuição , Doenças dos Animais/diagnóstico , Doenças dos Animais/prevenção & controle , Criação de Animais Domésticos/economia , Criação de Animais Domésticos/instrumentação , Criação de Animais Domésticos/métodos , Criação de Animais Domésticos/tendências , Animais , Automação/economia , Automação/instrumentação , Alarmes Clínicos/veterinária , Produção Agrícola/economia , Produção Agrícola/instrumentação , Produção Agrícola/métodos , Produção Agrícola/tendências , Percepção de Profundidade , Frutas/economia , Frutas/crescimento & desenvolvimento , Frutas/normas , Lasers , Gado , Aprendizado de Máquina , Aplicativos Móveis , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Monitorização Fisiológica/veterinária , Praguicidas/efeitos adversos , Praguicidas/economia , Praguicidas/provisão & distribuição , Doenças das Plantas/prevenção & controle , Plantas Daninhas/efeitos dos fármacos , Controle de Qualidade , Tecnologia de Sensoriamento Remoto/economia , Tecnologia de Sensoriamento Remoto/instrumentação , Tecnologia de Sensoriamento Remoto/tendências , Robótica/economia , Robótica/instrumentação , Robótica/tendências , Solo/química , Solo/normas , Transferência de Tecnologia , Fatores de Tempo , Verduras/economia , Verduras/crescimento & desenvolvimento , Verduras/normas
13.
Tree Physiol ; 31(6): 669-79, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21743059

RESUMO

A variety of thermal approaches are used to estimate sap flux density in stems of woody plants. Models have proved valuable tools for interpreting the behavior of heat pulse, heat balance and heat field deformation techniques, but have seldom been used to describe heat transfer dynamics for the heat dissipation method. Therefore, to better understand the behavior of heat dissipation probes, a model was developed that takes into account the thermal properties of wood, the physical dimensions and thermal characteristics of the probes, and the conductive and convective heat transfer that occurs due to water flow in the sapwood. Probes were simulated as aluminum tubes 20 mm in length and 2 mm in diameter, whereas sapwood, heartwood and bark each had a density and water fraction that determined their thermal properties. Base simulations assumed a constant sap flux density with sapwood depth and no wounding or physical disruption of xylem beyond the 2 mm diameter hole drilled for probe installation. Simulations across a range of sap flux densities showed that the dimensionless quantity k [defined as (ΔT(m) -ΔT)/ΔT, where ΔT(m) is the temperature differential (ΔT) between the heated and unheated probe under zero-flow conditions] was dependent on the thermal conductivity of the sapwood. The relationship between sap flux density and k was also sensitive to radial gradients in sap flux density and to xylem disruption near the probe. Monte Carlo analysis in which 1000 simulations were conducted while simultaneously varying thermal conductivity and wound diameter revealed that sap flux density and k showed considerable departure from the original calibration equation used with this technique. The departure was greatest for variation in sap flux density typical of ring-porous species. Depending on the specific combination of thermal conductivity and wound diameter, use of the original calibration equation resulted in an 81% under- to 48% overestimation of sap flux density at modest flux rates. Future studies should verify these simulations and assess their utility in estimating sap flux density for this widely used technique.


Assuntos
Modelos Biológicos , Árvores/fisiologia , Madeira/fisiologia , Xilema/fisiologia , Transporte Biológico , Método de Monte Carlo , Casca de Planta/fisiologia , Caules de Planta/fisiologia , Transpiração Vegetal , Temperatura , Água/fisiologia
14.
Cell ; 141(7): 1105-7, 2010 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-20602991

RESUMO

UK researchers are debating the merits of the new Wellcome Trust Investigator Awards. With concerns over public funding cuts for research, some question the timing of the charity's change in funding strategy.


Assuntos
Pesquisa Biomédica/economia , Apoio à Pesquisa como Assunto , Irlanda , Apoio ao Desenvolvimento de Recursos Humanos , Reino Unido
15.
J Am Psychiatr Nurses Assoc ; 14(4): 273-84, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21665771

RESUMO

BACKGROUND: Current health research strives to integrate biological, psychological, and social factors consistent with ecological models. Home-based biomarker specimens are consistent with an ecological approach, but deviations from laboratory norms could affect validity of results. OBJECTIVE: This article uses salivary cortisol specimens collected early in a perinatal mental health study to describe (a) return rate and returner characteristics, (b) adherence to procedures, (c) sources of laboratory error, (d) effects of deleting specimens with "nuisance" factors, and (e) effects that selection bias could have on cortisol concentration distribution. STUDY DESIGN: This includes methodological analysis of collection, assay, and preanalysis decision components. RESULTS: Rates of return do not differ by participants' sociodemographic, perinatal, or psychiatric characteristics. Excluding smokers affects representativeness. Selection bias in favor of more or less disadvantaged participants affects cortisol distribution. CONCLUSIONS: The large yield of useable specimens permits multivariate modeling of cortisol level in association with health outcomes, potentially enhancing ecological validity. J Am Psychiatr Nurses Assoc, 2008; 14(4), 273-284. DOI: 10.1177/1078390308322944.

16.
Invest Ophthalmol Vis Sci ; 47(7): 2885-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16799029

RESUMO

PURPOSE: To determine by conjoint analysis which factors in the management and treatment of glaucoma were of most importance to patients and to relate these factors to the patient's clinical glaucoma condition. METHODS: An interview-based study was performed. Demographic and visual function data are recorded. Participants completed the Visual Function Questionnaire-25 and ranked 10 hypothetical patient scenarios that contained different risks of moderate visual loss, postoperative complications, long-term blindness, use of topical medication, and glaucoma surgery. Conjoint analysis was performed to determine the relative importance of these factors for individuals and the group as a whole. RESULTS: Eighty-two patients were interviewed from two consultants' outpatient clinics. Forty-five were male and 37 female. Seventy-nine were white. The most important factors to patients with glaucoma were the risk of moderate visual impairment and the risk of blindness, with an importance of 38% and 27%, respectively. The use of topical medication had an importance of 11%. Proceeding to surgical intervention (trabeculectomy) had an importance of 15%, and the small risk of visual deterioration after surgery (trabeculectomy) had an importance of 9%. CONCLUSIONS: To patients, the most important factors regarding glaucoma and its treatment are the risks of moderate visual loss (the ability to continue to drive) and long-term blindness. The treatment methods used are of much less importance.


Assuntos
Glaucoma de Ângulo Aberto/terapia , Satisfação do Paciente/estatística & dados numéricos , Pacientes/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Hipertensivos/uso terapêutico , Cegueira/etiologia , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Medição de Risco , Inquéritos e Questionários , Trabeculectomia/métodos , Baixa Visão/etiologia
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