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1.
Sci Total Environ ; 832: 154922, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35364168

RESUMO

The analysis of the ingestion of microplastics (MP) by biota is frequently performed through invasive procedures such as chemical digestion protocols or by histological analysis of thin sections. Different, promising approaches for the observation of ingested MP particles pose so called tissue clearing methods. They are currently applied to organs, tissue samples, or whole organisms, rendering the sample transparent and enable to look inside an otherwise opaque environment. To date, there is a lack of methods to detect labeled MP inside an opaque organism's digestive tract without interfering with the sample's integrity. Therefore, our goal was to adapt the CUBIC tissue clearing protocol (Clear, Unobstructed Brain/Body Imaging Cocktails and Computational Analysis) for aquatic and terrestrial organisms of various functional feeding groups for the analysis of the uptake of fluorescent labeled microplastic (MP) particles. We included the buff-tailed bumblebee Bombus terrestris, the compost worm Eisenia fetida, the woodlouse Porcellio scaber, the freshwater shrimp Gammarus roeselii, and the quagga mussel Dreissena bugensis in the analysis. The adapted CUBIC method has led to transparency in all normally opaque organisms. It further offers a simple way of locating fluorescent labeled MP inside the digestive system of the different organisms while leaving them intact.


Assuntos
Dreissena , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Água Doce , Microplásticos , Plásticos/análise , Poluentes Químicos da Água/análise
2.
Z Evid Fortbild Qual Gesundhwes ; 150-152: 134-141, 2020 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-32451188

RESUMO

BACKGROUND: Coverage decisions are decisions by third party payers about whether and how much to pay for technologies or services, and under what conditions. Given their complexity, a systematic and transparent approach is needed. The DECIDE project, a GRADE working group initiative funded by the European Union, has developed GRADE Evidence to Decision (EtD) frameworks for different types of decisions, including coverage ones. METHODS: We used an iterative approach, including brainstorming to generate ideas, consultation with stakeholders, user testing, and pilot testing of the framework. RESULTS: The general structure of the EtD includes formulation of the question, an assessment using 12 criteria, and conclusions. Criteria that are relevant for coverage decisions are similar to those for clinical recommendations from a population perspective. Important differences between the two include the decision-making processes, accountability, and the nature of the judgments that need to be made for some criteria. Although cost-effectiveness is a key consideration when making coverage decisions, it may not be the determining factor. Strength of recommendation is not directly linked to the type of coverage decisions, but when there are important uncertainties, it may be possible to cover an intervention for a subgroup, in the context of research, with price negotiation, or with restrictions. CONCLUSION: The EtD provides a systematic and transparent approach for making coverage decisions. It helps ensure consideration of key criteria that determine whether a technology or service should be covered and that judgments are informed by the best available evidence.


Assuntos
Tomada de Decisões , Medicina Baseada em Evidências , União Europeia , Alemanha , Incerteza
3.
Cochrane Database Syst Rev ; 3: CD011518, 2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30916356

RESUMO

BACKGROUND: Breast cancer is the most common cancer in women. Diagnosis and treatment may drastically affect quality of life, causing symptoms such as sleep disorders, depression and anxiety. Mindfulness-based stress reduction (MBSR) is a programme that aims to reduce stress by developing mindfulness, meaning a non-judgmental, accepting moment-by-moment awareness. MBSR seems to benefit patients with mood disorders and chronic pain, and it may also benefit women with breast cancer. OBJECTIVES: To assess the effects of mindfulness-based stress reduction (MBSR) in women diagnosed with breast cancer. SEARCH METHODS: In April 2018, we conducted a comprehensive electronic search for studies of MBSR in women with breast cancer, in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and two trial registries (World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov). We also handsearched relevant conference proceedings. SELECTION CRITERIA: Randomised clinical trials (RCTs) comparing MBSR versus no intervention in women with breast cancer. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Using a standardised data form, the review authors extracted data in duplicate on methodological quality, participants, interventions and outcomes of interest (quality of life, fatigue, depression, anxiety, quality of sleep, overall survival and adverse events). For outcomes assessed with the same instrument, we used the mean difference (MD) as a summary statistic for meta-analysis; for those assessed with different instruments, we used the standardised mean difference (SMD). The effect of MBSR was assessed in the short term (end of intervention), medium term (up to 6 months after intervention) and long term (up to 24 months after intervention). MAIN RESULTS: Fourteen RCTs fulfilled our inclusion criteria, with most studies reporting that they included women with early breast cancer. Ten RCTs involving 1571 participants were eligible for meta-analysis, while four studies involving 185 participants did not report usable results. Queries to the authors of these four studies were unsuccessful. All studies were at high risk of performance and detection bias since participants could not be blinded, and only 3 of 14 studies were at low risk of selection bias. Eight of 10 studies included in the meta-analysis recruited participants with early breast cancer (the remaining 2 trials did not restrict inclusion to a certain cancer type). Most trials considered only women who had completed cancer treatment.MBSR may improve quality of life slightly at the end of the intervention (based on low-certainty evidence from three studies with a total of 339 participants) but may result in little to no difference up to 6 months (based on low-certainty evidence from three studies involving 428 participants). Long-term data on quality of life (up to two years after completing MBSR) were available for one study in 97 participants (MD 0.00 on questionnaire FACT-B, 95% CI -5.82 to 5.82; low-certainty evidence).In the short term, MBSR probably reduces fatigue (SMD -0.50, 95% CI -0.86 to -0.14; moderate-certainty evidence; 5 studies; 693 participants). It also probably slightly reduces anxiety (SMD -0.29, 95% CI -0.50 to -0.08; moderate-certainty evidence; 6 studies; 749 participants), and it reduces depression (SMD -0.54, 95% CI -0.86 to -0.22; high-certainty evidence; 6 studies; 745 participants). It probably slightly improves quality of sleep (SMD -0.38, 95% CI -0.79 to 0.04; moderate-certainty evidence; 4 studies; 475 participants). However, these confidence intervals (except for short-term depression) are compatible with both an improvement and little to no difference.In the medium term, MBSR probably results in little to no difference in medium-term fatigue (SMD -0.31, 95% CI -0.84 to 0.23; moderate-certainty evidence; 4 studies; 607 participants). The intervention probably slightly reduces anxiety (SMD -0.28, 95% CI -0.49 to -0.07; moderate-certainty evidence; 7 studies; 1094 participants), depression (SMD -0.32, 95% CI -0.58 to -0.06; moderate-certainty evidence; 7 studies; 1097 participants) and slightly improves quality of sleep (SMD -0.27, 95% CI -0.63 to 0.08; moderate-certainty evidence; 4 studies; 654 participants). However, these confidence intervals are compatible with both an improvement and little to no difference.In the long term, moderate-certainty evidence shows that MBSR probably results in little to no difference in anxiety (SMD -0.09, 95% CI -0.35 to 0.16; 2 studies; 360 participants) or depression (SMD -0.17, 95% CI -0.40 to 0.05; 2 studies; 352 participants). No long-term data were available for fatigue or quality of sleep.No study reported data on survival or adverse events. AUTHORS' CONCLUSIONS: MBSR may improve quality of life slightly at the end of the intervention but may result in little to no difference later on. MBSR probably slightly reduces anxiety, depression and slightly improves quality of sleep at both the end of the intervention and up to six months later. A beneficial effect on fatigue was apparent at the end of the intervention but not up to six months later. Up to two years after the intervention, MBSR probably results in little to no difference in anxiety and depression; there were no data available for fatigue or quality of sleep.


Assuntos
Neoplasias da Mama/psicologia , Atenção Plena , Estresse Psicológico/terapia , Ansiedade/psicologia , Depressão/psicologia , Fadiga/psicologia , Feminino , Humanos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Transtornos do Sono-Vigília/psicologia , Fatores de Tempo
4.
Cochrane Database Syst Rev ; 8: CD007476, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28809446

RESUMO

BACKGROUND: Thalassaemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from regular red blood cell transfusions. Iron chelation therapy is needed to prevent long-term complications.Both deferoxamine and deferiprone are effective; however, a review of the effectiveness and safety of the newer oral chelator deferasirox in people with thalassaemia is needed. OBJECTIVES: To assess the effectiveness and safety of oral deferasirox in people with thalassaemia and iron overload. SEARCH METHODS: We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 12 August 2016.We also searched MEDLINE, Embase, the Cochrane Library, Biosis Previews, Web of Science Core Collection and three trial registries: ClinicalTrials.gov; the WHO International Clinical Trials Registry Platform; and the Internet Portal of the German Clinical Trials Register: 06 and 07 August 2015. SELECTION CRITERIA: Randomised controlled studies comparing deferasirox with no therapy or placebo or with another iron-chelating treatment. DATA COLLECTION AND ANALYSIS: Two authors independently assessed risk of bias and extracted data. We contacted study authors for additional information. MAIN RESULTS: Sixteen studies involving 1807 randomised participants (range 23 to 586 participants) were included. Twelve two-arm studies compared deferasirox to placebo (two studies) or deferoxamine (seven studies) or deferiprone (one study) or the combination of deferasirox and deferoxamine to deferoxamine alone (one study). One study compared the combination of deferasirox and deferiprone to deferiprone in combination with deferoxamine. Three three-arm studies compared deferasirox to deferoxamine and deferiprone (two studies) or the combination of deferasirox and deferiprone to deferiprone and deferasirox monotherapy respectively (one study). One four-arm study compared two different doses of deferasirox to matching placebo groups.The two studies (a pharmacokinetic and a dose-escalation study) comparing deferasirox to placebo (n = 47) in people with transfusion-dependent thalassaemia showed that deferasirox leads to net iron excretion. In these studies, safety was acceptable and further investigation in phase II and phase III studies was warranted.Nine studies (1251 participants) provided data for deferasirox versus standard treatment with deferoxamine. Data suggest that a similar efficacy can be achieved depending on the ratio of doses of deferoxamine and deferasirox being compared. In the phase III study, similar or superior efficacy for the intermediate markers ferritin and liver iron concentration (LIC) could only be achieved in the highly iron-overloaded subgroup at a mean ratio of 1 mg of deferasirox to 1.8 mg of deferoxamine corresponding to a mean dose of 28.2 mg per day and 51.6 mg per day respectively. The pooled effects across the different dosing ratios are: serum ferritin, mean difference (MD) 454.42 ng/mL (95% confidence interval (CI) 337.13 to 571.71) (moderate quality evidence); LIC evaluated by biopsy or SQUID, MD 2.37 mg Fe/g dry weight (95% CI 1.68 to 3.07) (moderate quality evidence) and responder analysis, LIC 1 to < 7 mg Fe/g dry weight, risk ratio (RR) 0.80 (95% CI 0.69 to 0.92) (moderate quality evidence). The substantial heterogeneity observed could be explained by the different dosing ratios. Data on mortality (low quality evidence) and on safety at the presumably required doses for effective chelation therapy are limited. Patient satisfaction was better with deferasirox among those who had previously received deferoxamine treatment, RR 2.20 (95% CI 1.89 to 2.57) (moderate quality evidence). The rate of discontinuations was similar for both drugs (low quality evidence).For the remaining comparisons in people with transfusion-dependent thalassaemia, the quality of the evidence for outcomes assessed was low to very low, mainly due to the very small number of participants included. Four studies (205 participants) compared deferasirox to deferiprone; one of which (41 participants) revealed a higher number of participants experiencing arthralgia in the deferiprone group, but due to the large number of different types of adverse events reported and compared this result is uncertain. One study (96 participants) compared deferasirox combined with deferiprone to deferiprone with deferoxamine. Participants treated with the combination of the oral iron chelators had a higher adherence compared to those treated with deferiprone and deferoxamine, but no participants discontinued the study. In the comparisons of deferasirox versus combined deferasirox and deferiprone and that of deferiprone versus combined deferasirox and deferiprone (one study, 40 participants), and deferasirox and deferoxamine versus deferoxamine alone (one study, 94 participants), only a few patient-relevant outcomes were reported and no significant differences were observed.One study (166 participants) included people with non-transfusion dependent thalassaemia and compared two different doses of deferasirox to placebo. Deferasirox treatment reduced serum ferritin, MD -306.74 ng/mL (95% CI -398.23 to -215.24) (moderate quality evidence) and LIC, MD -3.27 mg Fe/g dry weight (95% CI -4.44 to -2.09) (moderate quality evidence), while the number of participants experiencing adverse events and rate of discontinuations (low quality evidence) was similar in both groups. No participant died, but data on mortality were limited due to a follow-up period of only one year (moderate quality evidence). AUTHORS' CONCLUSIONS: Deferasirox offers an important treatment option for people with thalassaemia and secondary iron overload. Based on the available data, deferasirox does not seem to be superior to deferoxamine at the usually recommended ratio of 1 mg of deferasirox to 2 mg of deferoxamine. However, similar efficacy seems to be achievable depending on the dose and ratio of deferasirox compared to deferoxamine. Whether this will result in similar efficacy and will translate to similar benefits in the long term, as has been shown for deferoxamine, needs to be confirmed. Data from randomised controlled trials on rare toxicities and long-term safety are still limited. However, after a detailed discussion of the potential benefits and risks, deferasirox could be offered as the first-line option to individuals who show a strong preference for deferasirox, and may be a reasonable treatment option for people showing an intolerance or poor adherence to deferoxamine.


Assuntos
Benzoatos/uso terapêutico , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Talassemia/complicações , Triazóis/uso terapêutico , Administração Oral , Benzoatos/administração & dosagem , Benzoatos/efeitos adversos , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Deferasirox , Deferiprona , Desferroxamina/administração & dosagem , Desferroxamina/uso terapêutico , Transfusão de Eritrócitos/efeitos adversos , Ferritinas/sangue , Humanos , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/etiologia , Satisfação do Paciente , Piridonas/administração & dosagem , Piridonas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Talassemia/mortalidade , Talassemia/terapia , Triazóis/administração & dosagem , Triazóis/efeitos adversos
5.
PLoS One ; 12(4): e0176210, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28441452

RESUMO

BACKGROUND: A meta-analysis as part of a systematic review aims to provide a thorough, comprehensive and unbiased statistical summary of data from the literature. However, relevant study results could be missing from a meta-analysis because of selective publication and inadequate dissemination. If missing outcome data differ systematically from published ones, a meta-analysis will be biased with an inaccurate assessment of the intervention effect. As part of the EU-funded OPEN project (www.open-project.eu) we conducted a systematic review that assessed whether the inclusion of data that were not published at all and/or published only in the grey literature influences pooled effect estimates in meta-analyses and leads to different interpretation. METHODS AND FINDINGS: Systematic review of published literature (methodological research projects). Four bibliographic databases were searched up to February 2016 without restriction of publication year or language. Methodological research projects were considered eligible for inclusion if they reviewed a cohort of meta-analyses which (i) compared pooled effect estimates of meta-analyses of health care interventions according to publication status of data or (ii) examined whether the inclusion of unpublished or grey literature data impacts the result of a meta-analysis. Seven methodological research projects including 187 meta-analyses comparing pooled treatment effect estimates according to different publication status were identified. Two research projects showed that published data showed larger pooled treatment effects in favour of the intervention than unpublished or grey literature data (Ratio of ORs 1.15, 95% CI 1.04-1.28 and 1.34, 95% CI 1.09-1.66). In the remaining research projects pooled effect estimates and/or overall findings were not significantly changed by the inclusion of unpublished and/or grey literature data. The precision of the pooled estimate was increased with narrower 95% confidence interval. CONCLUSIONS: Although we may anticipate that systematic reviews and meta-analyses not including unpublished or grey literature study results are likely to overestimate the treatment effects, current empirical research shows that this is only the case in a minority of reviews. Therefore, currently, a meta-analyst should particularly consider time, effort and costs when adding such data to their analysis. Future research is needed to identify which reviews may benefit most from including unpublished or grey data.


Assuntos
Disseminação de Informação/métodos , Metanálise como Assunto , Viés de Publicação , Humanos , Publicações
6.
BMJ Open ; 5(5): e006666, 2015 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-25943371

RESUMO

BACKGROUND: Dissemination bias in clinical research severely impedes informed decision-making not only for healthcare professionals and patients, but also for funders, research ethics committees, regulatory bodies and other stakeholder groups that make health-related decisions. Decisions based on incomplete and biased evidence cannot only harm people, but may also have huge financial implications by wasting resources on ineffective or harmful diagnostic and therapeutic measures, and unnecessary research. Owing to involvement of multiple stakeholders, it remains easy for any single group to assign responsibility for resolving the problem to others. OBJECTIVE: To develop evidence-informed general and targeted recommendations addressing the various stakeholders involved in knowledge generation and dissemination to help overcome the problem of dissemination bias on the basis of previously collated evidence. METHODS: Based on findings from systematic reviews, document analyses and surveys, we developed general and targeted draft recommendations. During a 2-day workshop in summer 2013, these draft recommendations were discussed with external experts and key stakeholders, and refined following a rigorous and transparent methodological approach. RESULTS: Four general, overarching recommendations applicable to all or most stakeholder groups were formulated, addressing (1) awareness raising, (2) implementation of targeted recommendations, (3) trial registration and results posting, and (4) systematic approaches to evidence synthesis. These general recommendations are complemented and specified by 47 targeted recommendations tailored towards funding agencies, pharmaceutical and device companies, research institutions, researchers (systematic reviewers and trialists), research ethics committees, trial registries, journal editors and publishers, regulatory agencies, benefit (health technology) assessment institutions and legislators. CONCLUSIONS: Despite various recent examples of dissemination bias and several initiatives to reduce it, the problem of dissemination bias has not been resolved. Tailored recommendations based on a comprehensive approach will hopefully help increase transparency in biomedical research by overcoming the failure to disseminate negative findings.


Assuntos
Pesquisa Biomédica , Consenso , Viés , Pesquisa Biomédica/organização & administração , Tomada de Decisões , Medicina Baseada em Evidências , Humanos , Editoração , Avaliação da Tecnologia Biomédica
7.
PLoS One ; 9(12): e114023, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25536072

RESUMO

BACKGROUND: The synthesis of published research in systematic reviews is essential when providing evidence to inform clinical and health policy decision-making. However, the validity of systematic reviews is threatened if journal publications represent a biased selection of all studies that have been conducted (dissemination bias). To investigate the extent of dissemination bias we conducted a systematic review that determined the proportion of studies published as peer-reviewed journal articles and investigated factors associated with full publication in cohorts of studies (i) approved by research ethics committees (RECs) or (ii) included in trial registries. METHODS AND FINDINGS: Four bibliographic databases were searched for methodological research projects (MRPs) without limitations for publication year, language or study location. The searches were supplemented by handsearching the references of included MRPs. We estimated the proportion of studies published using prediction intervals (PI) and a random effects meta-analysis. Pooled odds ratios (OR) were used to express associations between study characteristics and journal publication. Seventeen MRPs (23 publications) evaluated cohorts of studies approved by RECs; the proportion of published studies had a PI between 22% and 72% and the weighted pooled proportion when combining estimates would be 46.2% (95% CI 40.2%-52.4%, I2 = 94.4%). Twenty-two MRPs (22 publications) evaluated cohorts of studies included in trial registries; the PI of the proportion published ranged from 13% to 90% and the weighted pooled proportion would be 54.2% (95% CI 42.0%-65.9%, I2 = 98.9%). REC-approved studies with statistically significant results (compared with those without statistically significant results) were more likely to be published (pooled OR 2.8; 95% CI 2.2-3.5). Phase-III trials were also more likely to be published than phase II trials (pooled OR 2.0; 95% CI 1.6-2.5). The probability of publication within two years after study completion ranged from 7% to 30%. CONCLUSIONS: A substantial part of the studies approved by RECs or included in trial registries remains unpublished. Due to the large heterogeneity a prediction of the publication probability for a future study is very uncertain. Non-publication of research is not a random process, e.g., it is associated with the direction of study findings. Our findings suggest that the dissemination of research findings is biased.


Assuntos
Ensaios Clínicos como Assunto , Comitês de Ética em Pesquisa , Publicações , Sistema de Registros , Estudos de Coortes , Humanos , Probabilidade , Viés de Publicação , Fatores de Tempo
8.
Cochrane Database Syst Rev ; (10): CD007461, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25348770

RESUMO

BACKGROUND: The myelodysplastic syndrome (MDS) comprises a diverse group of haematopoietic stem cell disorders. Due to symptomatic anaemia, most people with MDS require supportive therapy including repeated red blood cell (RBC) transfusions. In combination with increased iron absorption, this contributes to the accumulation of iron resulting in secondary iron overload and the risk of organ dysfunction and reduced life expectancy. Since the human body has no natural means of removing excess iron, iron chelation therapy, i.e. the pharmacological treatment of iron overload, is usually recommended. However, it is unclear whether or not the newer oral chelator deferasirox leads to relevant benefit. OBJECTIVES: To evaluate the effectiveness and safety of oral deferasirox for managing iron overload in people with myelodysplastic syndrome (MDS). SEARCH METHODS: We searched the following databases up to 03 April 2014: MEDLINE, EMBASE, The Cochrane Library, Biosis Previews, Web of Science, Derwent Drug File and four trial registries: Current Controlled Trials (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), ICTRP (www.who.int./ictrp/en/), and German Clinical Trial Register (www.drks.de). SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing deferasirox with no therapy, placebo or with another iron-chelating treatment schedule. DATA COLLECTION AND ANALYSIS: We did not identify any trials eligible for inclusion in this review. MAIN RESULTS: No trials met our inclusion criteria. However, we identified three ongoing and one completed trial (published as an abstract only and in insufficient detail to permit us to decide on inclusion) comparing deferasirox with deferoxamine, placebo or no treatment. AUTHORS' CONCLUSIONS: We planned to report evidence from RCTs that evaluated the effectiveness of deferasirox compared to either placebo, no treatment or other chelating regimens, such as deferoxamine, in people with MDS. However, we did not identify any completed RCTs addressing this question.We found three ongoing and one completed RCT (published as an abstract only and in insufficient detail) comparing deferasirox with deferoxamine, placebo or no treatment and data will hopefully be available soon. These results will be important to inform physicians and patients on the advantages and disadvantages of this treatment option.


Assuntos
Benzoatos/uso terapêutico , Terapia por Quelação/métodos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Síndromes Mielodisplásicas/complicações , Triazóis/uso terapêutico , Deferasirox , Humanos
9.
Z Evid Fortbild Qual Gesundhwes ; 108(5-6): 333-47, 2014.
Artigo em Alemão | MEDLINE | ID: mdl-25066353

RESUMO

UNLABELLED: Presenting continuous outcomes in Summary of Findings tables presents particular challenges to interpretation. When each study uses the same outcome measure, and the units of that measure are intuitively interpretable (e.g., duration of hospitalisation, duration of symptoms), presenting differences in means is usually desirable. When the natural units of the outcome measure are not easily interpretable, choosing a threshold to create a binary outcome and presenting relative and absolute effects become a more attractive alternative. When studies use different measures of the same construct, calculating summary measures requires converting to the same units of measurement for each study. The longest standing and most widely used approach is to divide the difference in means in each study by its standard deviation and present pooled results in standard deviation units (standardised mean difference). Disadvantages of this approach include vulnerability to varying degrees of heterogeneity in the underlying populations and difficulties in interpretation. Alternatives include presenting results in the units of the most popular or interpretable measure, converting to dichotomous measures and presenting relative and absolute effects, presenting the ratio of the means of intervention and control groups, and presenting the results in minimally important difference units. We outline the merits and limitations of each alternative and provide guidance for meta-analysts and guideline developers. KEY POINTS: Summary of Findings tables provide succinct presentations of evidence quality and magnitude of effects. Summarising the findings of continuous outcomes presents special challenges to interpretation that become daunting when individual trials use different measures for the same construct. The most commonly used approach to providing pooled estimates for different measures, presenting results in standard deviation units, has limitations related to both statistical properties and interpretability. Potentially preferable alternatives include presenting results in the natural units of the most popular measure, transforming into a binary outcome and presenting relative and absolute effects, presenting the ratio of the means of intervention and control groups, and presenting results in preestablished minimally important difference units.


Assuntos
Ensaios Clínicos Controlados como Assunto , Coleta de Dados , Determinação de Ponto Final , Medicina Baseada em Evidências , Guias de Prática Clínica como Assunto , Garantia da Qualidade dos Cuidados de Saúde , Adulto , Criança , Feminino , Alemanha , Humanos , Masculino , Projetos de Pesquisa
10.
Cochrane Database Syst Rev ; 5: CD007477, 2014 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-24893174

RESUMO

BACKGROUND: Sickle cell disease (SCD) is a group of genetic haemoglobin disorders, that occurs in about 2.2 per 1000 births worldwide. Increasingly, some people with SCD develop secondary iron overload due to occasional red blood cell transfusions or are on long-term transfusion programmes for e.g. secondary stroke prevention. Iron chelation therapy can prevent long-term complications.Deferoxamine and deferiprone have been found to be efficacious. However, questions exist about the effectiveness and safety of the newer oral chelator deferasirox. OBJECTIVES: To assess the effectiveness and safety of oral deferasirox in people with SCD and secondary iron overload. SEARCH METHODS: We searched the Cystic Fibrosis & Genetic Disorders Group's Haemoglobinopathies Trials Register: date of most recent search:13 March 2014.We searched MEDLINE, Embase, Biosis Previews, Web of Science, Derwent Drug File, XTOXLINE, EBMR and The Cochrane Library, respectively; date of most recent searches: 02 August 2013.We searched four trial registries: www.controlled-trials.com; www.clinicaltrials.gov; www.who.int./ictrp/en/; www.drks.de; date of most recent searches: 03 June 2013. SELECTION CRITERIA: Randomised controlled trials comparing deferasirox with no therapy or placebo or with another iron chelating treatment schedule. DATA COLLECTION AND ANALYSIS: Two authors independently assessed risk of bias and extracted data. We contacted the corresponding study authors for additional information. MAIN RESULTS: Two studies (with 203 and 212 people) comparing the efficacy and safety of deferasirox and deferoxamine after 12 months and 24 weeks, respectively, were included. The overall quality, according to GRADE, for the main outcomes was moderate to low. Only limited data were available on mortality and end-organ damage, although one study did assess mortality, relative risk 1.26 (95% confidence interval 0.05 to 30.41), the 24-week follow up was too short to allow us to draw firm conclusions. One study reported a relative risk of 1.26 for the incidence of type 2 diabetes mellitus (95% confidence interval 0.05 to 30.41). Serum ferritin reduction was significantly greater with deferoxamine, mean difference of change of 440.69 µg/l (95% confidence interval 11.73 to 869.64). Liver iron concentration (reported in one study) measured by superconduction quantum interference device showed no significant difference for the overall group of patients adjusted for transfusion category, mean difference -0.20 mg Fe/g dry weight (95% confidence interval -3.15 to 2.75).The occurrence of serious adverse events did not differ between drugs. Nausea, diarrhoea and rash occurred significantly more often in people treated with deferasirox, while adverse events of any kind were more often reported for patients treated with deferoxamine (one study). The mean increase of creatinine was also significantly higher with deferasirox, mean difference 3.24 (95% confidence interval 0.45 to 6.03). Long-term adverse events could not be measured in the included studies (follow up 52 weeks and 24 weeks). Patient satisfaction and the likelihood of continuing treatment, were significantly better with deferasirox. AUTHORS' CONCLUSIONS: Deferasirox appears to be of similar efficacy to deferoxamine depending on depending on the appropriate ratio of doses of deferoxamine and deferasirox being compared. However, only limited evidence is available assessing the efficacy regarding patient-important outcomes. The short-term safety of deferasirox seems to be acceptable, however, follow up in the available studies was too short to assess long-term side effects. Long-term safety and efficacy data are available from a non-controlled extension phase not included in our review; however, no valid comparative conclusions can be drawn and future studies should assess comparatively long-term outcomes both for safety and efficacy.

11.
Environ Manage ; 29(4): 566-77, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12071506

RESUMO

Basic information on where nonnative plant species have successfully invaded is lacking. We assessed the vulnerability of 22 vegetation types (25 sets of four plots in nine study areas) to nonnative plant invasions in the north-central United States. In general, habitats with high native species richness were more heavily invaded than species-poor habitats, low-elevation areas were more invaded than high-elevation areas, and riparian zones were more invaded than nearby upland sites. For the 100 1000-m2 plots (across all vegetation types), 50% of the variation in nonnative species richness was explained by longitude, latitude, native plant species richness, soil total percentage nitrogen, and mean maximum July temperature (n = 100 plots; P < 0.001). At the vegetation-type scale (n = 25 sets of four 1000-m2 plots/type), 64% of the variation in nonnative species richness was explained by native plant species richness, elevation, and October to June precipitation (P < 0.001). The foliar cover of nonnative species (log) was strongly positively correlated with the nonnative species richness at the plot scale (r = 0.77, P < 0.001) and vegetation-type scale (r = 0.83, P < 0.001). We concluded that, at the vegetation-type and regional scales in the north-central United States, (1) vegetation types rich in native species are often highly vulnerable to invasion by nonnative plant species; (2) where several nonnative species become established, nonnative species cover can substantially increase; (3) the attributes that maintain high native plant species richness (high light, water, nitrogen, and temperatures) also help maintain nonnative plant species richness; and (4) more care must be taken to preserve native species diversity in highly vulnerable habitats.


Assuntos
Conservação dos Recursos Naturais , Plantas , Altitude , Ecossistema , Meio Ambiente , Previsões , Dinâmica Populacional , Medição de Risco , Estados Unidos
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