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1.
CMAJ ; 186(15): E568-78, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25225226

RESUMO

BACKGROUND: Frequent users of health care services are a relatively small group of patients who account for a disproportionately large amount of health care utilization. We conducted a meta-analysis of the effectiveness of interventions to improve the coordination of care to reduce health care utilization in this patient group. METHODS: We searched MEDLINE, Embase and the Cochrane Library from inception until May 2014 for randomized clinical trials (RCTs) assessing quality improvement strategies for the coordination of care of frequent users of the health care system. Articles were screened, and data abstracted and appraised for quality by 2 reviewers, independently. Random effects meta-analyses were conducted. RESULTS: We identified 36 RCTs and 14 companion reports (total 7494 patients). Significantly fewer patients in the intervention group than in the control group were admitted to hospital (relative risk [RR] 0.81, 95% confidence interval [CI] 0.72-0.91). In subgroup analyses, a similar effect was observed among patients with chronic medical conditions other than mental illness, but not among patients with mental illness. In addition, significantly fewer patients 65 years and older in the intervention group than in the control group visited emergency departments (RR 0.69, 95% CI 0.54-0.89). INTERPRETATION: We found that quality improvement strategies for coordination of care reduced hospital admissions among patients with chronic conditions other than mental illness and reduced emergency department visits among older patients. Our results may help clinicians and policy-makers reduce utilization through the use of strategies that target the system (team changes, case management) and the patient (promotion of self-management).


Assuntos
Prestação Integrada de Cuidados de Saúde/organização & administração , Serviços de Saúde/estatística & dados numéricos , Melhoria de Qualidade , Humanos
2.
BMC Med ; 11: 153, 2013 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-23800265

RESUMO

BACKGROUND: Influenza vaccines are most effective when the antigens in the vaccine match those of circulating strains. However, antigens contained in the vaccines do not always match circulating strains. In the present work we aimed to examine the vaccine efficacy (VE) afforded by influenza vaccines when they are not well matched to circulating strains. METHODS: We identified randomized clinical trials (RCTs) through MEDLINE, EMBASE, the Cochrane Library, and references of included RCTs. RCTs reporting laboratory-confirmed influenza among healthy participants vaccinated with antigens of matching and non-matching influenza strains were included. Two independent reviewers screened citations/full-text articles, abstracted data, and appraised risk of bias. Conflicts were resolved by discussion. A random effects meta-analysis was conducted. VE was calculated using the following formula: (1 - relative risk × 100%). RESULTS: We included 34 RCTs, providing data on 47 influenza seasons and 94,821 participants. The live-attenuated influenza vaccine (LAIV) showed significant protection against mismatched (six RCTs, VE 54%, 95% confidence interval (CI) 28% to 71%) and matched (seven RCTs, VE 83%, 95% CI 75% to 88%) influenza strains among children aged 6 to 36 months. Differences were observed between the point estimates for mismatched influenza A (five RCTs, VE 75%, 95% CI 41% to 90%) and mismatched influenza B (five RCTs, VE 42%, 95% CI 22% to 56%) estimates among children aged 6 to 36 months. The trivalent inactivated vaccine (TIV) also afforded significant protection against mismatched (nine RCTs, VE 52%, 95% CI 37% to 63%) and matched (eight RCTs, VE 65%, 95% CI 54% to 73%) influenza strains among adults. Numerical differences were observed between the point estimates for mismatched influenza A (five RCTs, VE 64%, 95% CI 23% to 82%) and mismatched influenza B (eight RCTs, VE 52%, 95% CI 19% to 72%) estimates among adults. Statistical heterogeneity was low (I2 <50%) across all meta-analyses, except for the LAIV meta-analyses among children (I2 = 79%). CONCLUSIONS: The TIV and LAIV vaccines can provide cross protection against non-matching circulating strains. The point estimates for VE were different for matching versus non-matching strains, with overlapping CIs.


Assuntos
Vacinas contra Influenza/genética , Vacinas contra Influenza/uso terapêutico , Influenza Humana/genética , Influenza Humana/prevenção & controle , Proteção Cruzada/genética , Humanos , Influenza Humana/virologia , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Especificidade da Espécie , Resultado do Tratamento , Vacinas Atenuadas/genética , Vacinas Atenuadas/uso terapêutico
3.
CMAJ ; 185(16): 1393-401, 2013 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-24043661

RESUMO

BACKGROUND: Cognitive enhancers, including cholinesterase inhibitors and memantine, are used to treat dementia, but their effectiveness for mild cognitive impairment is unclear. We conducted a systematic review to examine the efficacy and safety of cognitive enhancers for mild cognitive impairment. METHODS: Our eligibility criteria were studies of the effects of donepezil, rivastigmine, galantamine or memantine on mild cognitive impairment reporting cognition, function, behaviour, global status, and mortality or harms. We identified relevant material by searching electronic databases (e.g., MEDLINE, Embase), the references of included studies, trial registries and conference proceedings, and by contacting experts. Two reviewers independently screened the results of the literature search, abstracted data and appraised risk of bias using the Cochrane risk-of-bias tool. RESULTS: We screened 15,554 titles and abstracts and 1384 full-text articles. Eight randomized clinical trials and 3 companion reports met our inclusion criteria. We found no significant effects of cognitive enhancers on cognition (Mini-Mental State Examination: 3 randomized clinical trials [RCTs], mean difference [MD] 0.14, 95% confidence interval [CI] -0.22 to 0.50; Alzheimer's Disease Assessment Scale - cognition subscale: 3 RCTs, standardized MD -0.07, 95% CI-0.16 to 0.01]) or function (Alzheimer's Disease Cooperative Study activities of daily living inventory: 2 RCTs, MD 0.30, 95% CI -0.26 to 0.86). Cognitive enhancers were associated with higher risks of nausea, diarrhea and vomiting than placebo. INTERPRETATION: Cognitive enhancers did not improve cognition or function among patients with mild cognitive impairment and were associated with a greater risk of gastrointestinal harms. Our findings do not support the use of cognitive enhancers for mild cognitive impairment.


Assuntos
Disfunção Cognitiva/tratamento farmacológico , Nootrópicos/uso terapêutico , Inibidores da Colinesterase/uso terapêutico , Donepezila , Galantamina/uso terapêutico , Humanos , Indanos/uso terapêutico , Memantina/uso terapêutico , Fenilcarbamatos/uso terapêutico , Piperidinas/uso terapêutico , Rivastigmina , Resultado do Tratamento
4.
Clin Trials ; 10(1): 54-62, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23263520

RESUMO

BACKGROUND: Most often, sample size determinations for randomized clinical trials are based on frequentist approaches that depend on somewhat arbitrarily chosen factors, such as type I and II error probabilities and the smallest clinically important difference. As an alternative, many authors have proposed decision-theoretic (full Bayesian) approaches, often referred to as value of information methods that attempt to determine the sample size that maximizes the difference between the trial's expected utility and its expected cost, referred to as the expected net gain. Taking an industry perspective, Willan proposes a solution in which the trial's utility is the increase in expected profit. Furthermore, Willan and Kowgier, taking a societal perspective, show that multistage designs can increase expected net gain. PURPOSE: The purpose of this article is to determine the optimal sample size using value of information methods for industry-based, multistage adaptive randomized clinical trials, and to demonstrate the increase in expected net gain realized. At the end of each stage, the trial's sponsor must decide between three actions: continue to the next stage, stop the trial and seek regulatory approval, or stop the trial and abandon the drug. METHODS: A model for expected total profit is proposed that includes consideration of per-patient profit, disease incidence, time horizon, trial duration, market share, and the relationship between trial results and probability of regulatory approval. The proposed method is extended to include multistage designs with a solution provided for a two-stage design. An example is given. RESULTS: Significant increases in the expected net gain are realized by using multistage designs. LIMITATIONS: The complexity of the solutions increases with the number of stages, although far simpler near-optimal solutions exist. The method relies on the central limit theorem, assuming that the sample size is sufficiently large so that the relevant statistics are normally distributed. CONCLUSION: From a value of information perspective, the use of multistage designs in industry trials leads to significant gains in the expected net gain.


Assuntos
Pesquisa Biomédica/economia , Coleta de Dados/métodos , Aprovação de Drogas/economia , Indústria Farmacêutica/economia , Ensaios Clínicos Controlados Aleatórios como Assunto/economia , Análise Custo-Benefício , Técnicas de Apoio para a Decisão , Modelos Econômicos , Modelos Estatísticos , Projetos de Pesquisa , Tamanho da Amostra
5.
BMC Health Serv Res ; 12: 346, 2012 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-23031428

RESUMO

BACKGROUND: Venous leg ulcers, affecting approximately 1% of the population, are costly to manage due to poor healing and high recurrence rates. We evaluated an evidence-informed leg ulcer care protocol with two frequently used high compression systems: 'four-layer bandage' (4LB) and 'short-stretch bandage' (SSB). METHODS: We conducted a cost-effectiveness analysis using individual patient data from the Canadian Bandaging Trial, a publicly funded, pragmatic, randomized trial evaluating high compression therapy with 4LB (n = 215) and SSB (n = 209) for community care of venous leg ulcers. We estimated costs (in 2009-2010 Canadian dollars) from the societal perspective and used a time horizon corresponding to each trial participant's first year. RESULTS: Relative to SSB, 4LB was associated with an average 15 ulcer-free days gained, although the 95% confidence interval [-32, 21 days] crossed zero, indicating no treatment difference; an average health benefit of 0.009 QALYs gained [-0.019, 0.037] and overall, an average cost increase of $420 [$235, $739] (due to twice as many 4LB bandages used); or equivalently, a cost of $46,667 per QALY gained. If decision makers are willing to pay from $50,000 to $100,000 per QALY, the probability of 4LB being more cost effective increased from 51% to 63%. CONCLUSIONS: Our findings differ from the emerging clinical and economic evidence that supports high compression therapy with 4LB, and therefore suggest another perspective on high compression practice, namely when delivered by trained registered nurses using an evidence-informed protocol, both 4LB and SSB systems offer comparable effectiveness and value for money.


Assuntos
Bandagens Compressivas/economia , Úlcera Varicosa/terapia , Idoso , Canadá , Protocolos Clínicos , Análise Custo-Benefício , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Anos de Vida Ajustados por Qualidade de Vida , Resultado do Tratamento , Úlcera Varicosa/economia
6.
Cochrane Database Syst Rev ; (9): MR000025, 2011 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-21901737

RESUMO

BACKGROUND: The importance of appraising the risk of bias of studies included in systematic reviews is well-established. However, uncertainty remains surrounding the method by which risk of bias assessments should be conducted. Specifically, no summary of evidence exists as to whether blinded (i.e. the assessor is unaware of the study author's name, institution, sponsorship, journal, etc.) versus unblinded assessments of risk of bias yield systematically different assessments in a systematic review. OBJECTIVES: To determine whether blinded versus unblinded assessments of risk of bias yield systematically different assessments in a systematic review. SEARCH STRATEGY: We searched MEDLINE (1966 to September week 4 2009), CINAHL (1982 to May week 3 2008), All EBM Reviews (inception to 6 October 2009), EMBASE (1980 to 2009 week 40) and HealthStar (1966 to September week 4 2009) (all Ovid interface). We applied no restrictions regarding language of publication, publication status or study design. We examined reference lists of included studies and contacted experts for potentially relevant literature. SELECTION CRITERIA: We included any study that examined blinded versus unblinded assessments of risk of bias included within a systematic review. DATA COLLECTION AND ANALYSIS: We extracted information from each of the included studies using a pre-specified 16-item form. We summarized the level of agreement between blinded and unblinded assessments of risk of bias descriptively. We calculated the standardized mean difference whenever possible. MAIN RESULTS: We included six randomized controlled trials (RCTs). Four studies had unclear risk of bias and two had high risk of bias. The results of these RCTs were not consistent; two demonstrated no differences between blinded and unblinded assessments, two found that blinded assessments had significantly lower quality scores, and another observed significantly higher quality scores for blinded assessments. The remaining study did not report the level of significance. We pooled five studies reporting sufficient information in a meta-analysis. We observed no statistically significant difference in risk of bias assessments between blinded or unblinded assessments (standardized mean difference -0.13, 95% confidence interval -0.42 to 0.16). The mean difference might be slightly inaccurate, as we did not adjust for clustering in our meta-analysis. We observed inconsistency of results visually and noted statistical heterogeneity. AUTHORS' CONCLUSIONS: Our review highlights that discordance exists between studies examining blinded versus unblinded risk of bias assessments at the systematic review level. The best approach to risk of bias assessment remains unclear, however, given the increased time and resources required to conceal reports effectively, it may not be necessary for risk of bias assessments to be conducted under blinded conditions in a systematic review.


Assuntos
Viés de Publicação , Literatura de Revisão como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco
7.
BMC Infect Dis ; 6: 174, 2006 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-17147828

RESUMO

BACKGROUND: Infection rates for many infectious diseases have declined over the past century. This has created a cohort effect, whereby older individuals experienced a higher infection rate in their past than younger individuals do now. As a result, age-stratified seroprevalence profiles often differ from what would be expected from constant infection rates. METHODS: Here, we account for the cohort effect by fitting an age-structured compartmental model with declining transmission rates to Hepatitis A seroprevalence data for Canadian-born individuals. We compare the predicted impact of universal vaccination with and without including the cohort effect in the dynamic model. RESULTS: We find that Hepatitis A transmissibility has declined by a factor of 2.8 since the early twentieth century. When the cohort effect is not included in the model, incidence and mortality both with and without vaccination are significantly over-predicted. Incidence (respectively mortality) over a 20 year period of universal vaccination is 34% (respectively 90%) higher than if the cohort effect is included. The percentage reduction in incidence and mortality due to vaccination are also over-predicted when the cohort effect is not included. Similar effects are likely for many other infectious diseases where infection rates have declined significantly over past decades and where immunity is lifelong. CONCLUSION: Failure to account for cohort effects has implications for interpreting seroprevalence data and predicting the impact of vaccination programmes with dynamic models. Cohort effects should be included in dynamic modelling studies whenever applicable.


Assuntos
Vacinas contra Hepatite A , Hepatite A/epidemiologia , Hepatite A/prevenção & controle , Programas de Imunização , Modelos Biológicos , Adolescente , Adulto , Fatores Etários , Canadá/epidemiologia , Criança , Pré-Escolar , Efeito de Coortes , Estudos de Coortes , Hepatite A/transmissão , Humanos , Incidência , Lactente , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Viagem
8.
Syst Rev ; 1: 31, 2012 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-22742585

RESUMO

BACKGROUND: Approximately 35 million people world-wide have Alzheimer's disease and this is projected to nearly double by 2030. Cognitive enhancers, including cholinesterase inhibitors (for example, donepezil, galantamine and rivastigmine) and memantine (N-methyl-D-aspartic acid (NMDA) receptor antagonist) have been approved for the treatment of Alzheimer's disease in many countries. Our objective is to evaluate the comparative effectiveness, safety, and cost of cognitive enhancers for Alzheimer's disease through a systematic review. METHODS/DESIGN: Studies examining the efficacy, safety, and cost of cognitive enhancers compared to placebo, supportive care, and other cognitive enhancers for Alzheimer's patients will be included. The primary outcome is cognition and secondary outcomes include function, behavior, quality of life, safety, and cost. Experimental studies (randomized controlled trials, quasi-randomized controlled trials, controlled clinical trials), quasi-experimental studies (controlled before-after, interrupted time series), and observational studies (cohort, case-control studies) will be eligible for inclusion. Inclusion will not be limited by publication status, time period or language of dissemination.We will search electronic databases (for example, MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, Ageline) from inception onwards. The electronic database search will be supplemented by searching for grey literature (for example, conference proceedings, searches in Google and relevant organization websites). Two reviewers will independently screen the studies for inclusion using the eligibility criteria established a priori and independently extract data. Risk of bias will be assessed using the Cochrane Risk of Bias tool for experimental and quasi-experimental studies and the Newcastle Ottawa Scale for observational studies. If deemed appropriate, meta-analysis and network (that is, indirect comparisons) meta-analysis will be conducted. DISCUSSION: Our systematic review will inform the decision of healthcare providers, policy-makers, Alzheimer's patients and family members about the use of cognitive enhancers, by improving their understanding of the costs, benefits and harms that are associated with these agents. PROSPERO REGISTRY NUMBER: CRD42012001948.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Metanálise como Assunto , Nootrópicos/uso terapêutico , Revisões Sistemáticas como Assunto , Humanos , Nootrópicos/economia , Projetos de Pesquisa
9.
Syst Rev ; 1: 25, 2012 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-22647316

RESUMO

BACKGROUND: Elderly individuals who have memory problems without significant limitations in activities of daily living are often diagnosed as having mild cognitive impairment (MCI). Some of these individuals progress to dementia. Several cognitive enhancers (for example donepezil, galantamine, rivastigmine, memantine) have been approved for use in people with Alzheimer's dementia but their use in patients with MCI is unclear. We aimed to determine the comparative effectiveness, safety, and cost of cognitive enhancers for MCI through a systematic review and network (that is, indirect comparisons) meta-analysis. DESIGN/METHODS: We will include studies that examine the use of cognitive enhancers compared to placebo, supportive care, or other cognitive enhancers among patients diagnosed with MCI. Outcomes of interest include cognition and function (primary outcomes), as well as behavior, quality of life, safety, and cost (secondary outcomes). We will include all experimental studies (randomized controlled trials, quasi-randomized controlled trials, controlled clinical trials), quasi-experimental studies (controlled before-after, interrupted time series), and observational studies (cohort, case-control). Studies will be included regardless of publication status (that is, we will include unpublished studies), year, or language of dissemination.To identify potentially relevant material, we will search the following electronic databases from inception onwards: MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, and Ageline. The electronic database search will be supplemented by scanning the reference lists of included studies, searching Google and organization websites for unpublished or difficult to locate material literature, and contacting experts.Two reviewers will independently screen the studies for inclusion using the eligibility criteria established a priori and independently extract data. Risk of bias will be assessed using the Cochrane Risk of Bias tool for experimental and quasi-experimental studies and the Newcastle Ottawa Scale for observational epidemiology studies. Meta-analysis and network meta-analysis are planned, if the studies are deemed statistically, methodologically, and clinically homogenous. DISCUSSION: Our systematic review will provide important information regarding the benefits, costs, and harms of cognitive enhancers for patients with MCI. This information can be used to assist healthcare providers, policy-makers, MCI patients and their family regarding the use of these agents. PROSPERO REGISTRY NUMBER: CRD42012002234.


Assuntos
Disfunção Cognitiva/tratamento farmacológico , Metanálise como Assunto , Nootrópicos/uso terapêutico , Revisões Sistemáticas como Assunto , Humanos , Projetos de Pesquisa
10.
Am J Cardiol ; 107(5): 690-6, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21215382

RESUMO

We evaluated whether telehealth counseling augments lifestyle change and risk factor decrease in subjects at high risk for primary or secondary cardiovascular events compared to a recommended guideline for brief preventive counseling. Subjects at high risk or with coronary heart disease (35 to 74 years of age, n = 680) were randomized to active control (risk factor feedback, brief advice, handouts) or telehealth lifestyle counseling (active control plus 6 weekly 1-hour teleconferenced sessions to groups of 4 to 8 subjects). Primary outcome was questionnaire assessment of adherence to daily exercise/physical activity and diet (daily vegetable and fruit intake and restriction of fat and salt) after treatment and at 6-month follow-up. Secondary outcomes were systolic and diastolic blood pressures, ratio of total to high-density lipoprotein cholesterol, and 10-year absolute risk for coronary disease. After treatment and at 6-month follow-up, adherence increased for telehealth versus control in exercise (29.3% and 18.4% vs 2.5% and 9.3%, respectively, odds ratio 1.60, 95% confidence interval 1.2 to 2.1) and diet (37.1% and 38.1% vs 16.7% and 33.3%, respectively, odds ratio 1.41, 95% confidence interval 1.1 to 1.9). Telehealth versus control had greater 6-month decreases in blood pressure (mean ± SE, systolic -4.8 ± 0.8 vs -2.8 ± 0.9 mm Hg, p = 0.04; diastolic -2.7 ± 0.5 vs -1.5 ± 0.6 mm Hg, p = 0.04). Decreases in cholesterol ratio and 10-year absolute risk were significant for the 2 groups. In conclusion, telehealth counseling augments therapeutic lifestyle change in subjects at high risk for cardiovascular events compared to a recommended guideline for brief preventive counseling.


Assuntos
Relações Comunidade-Instituição , Doença das Coronárias/prevenção & controle , Aconselhamento/métodos , Estilo de Vida , Educação de Pacientes como Assunto/métodos , Telemedicina/métodos , Adulto , Idoso , Feminino , Seguimentos , Guias como Assunto , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Método Simples-Cego
11.
Hypertension ; 55(4): 1033-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20194302

RESUMO

It is not established whether behavioral interventions add benefit to pharmacological therapy for hypertension. We hypothesized that behavioral neurocardiac training (BNT) with heart rate variability biofeedback would reduce blood pressure further by modifying vagal heart rate modulation during reactivity and recovery from standardized cognitive tasks ("mental stress"). This randomized, controlled trial enrolled 65 patients with uncomplicated hypertension to BNT or active control (autogenic relaxation), with six 1-hour sessions over 2 months with home practice. Outcomes were analyzed with linear mixed models that adjusted for antihypertensive drugs. BNT reduced daytime and 24-hour systolic blood pressures (-2.4+/-0.9 mm Hg, P=0.009, and -2.1+/-0.9 mm Hg, P=0.03, respectively) and pulse pressures (-1.7+/-0.6 mm Hg, P=0.004, and -1.4+/-0.6 mm Hg, P=0.02, respectively). No effect was observed for controls (P>0.10 for all indices). BNT also increased RR-high-frequency power (0.15 to 0.40 Hz; P=0.01) and RR interval (P<0.001) during cognitive tasks. Among controls, high-frequency power was unchanged (P=0.29), and RR interval decreased (P=0.03). Neither intervention altered spontaneous baroreflex sensitivity (P>0.10). In contrast to relaxation therapy, BNT with heart rate variability biofeedback modestly lowers ambulatory blood pressure during wakefulness, and it augments tonic vagal heart rate modulation. It is unknown whether efficacy of this treatment can be improved with biofeedback of baroreflex gain. BNT, alone or as an adjunct to drug therapy, may represent a promising new intervention for hypertension.


Assuntos
Barorreflexo/fisiologia , Biorretroalimentação Psicológica/fisiologia , Frequência Cardíaca/fisiologia , Hipertensão/terapia , Adulto , Análise de Variância , Pressão Sanguínea/fisiologia , Distribuição de Qui-Quadrado , Terapia Cognitivo-Comportamental , Feminino , Humanos , Hipertensão/fisiopatologia , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Índice de Gravidade de Doença , Estresse Psicológico/fisiopatologia , Resultado do Tratamento
12.
Open Med ; 3(4): e210-4, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-21688757

RESUMO

BACKGROUND: Cochrane reviews are regarded as scientifically rigorous, yet a review's time to publication can be affected by factors such as the statistical significance of the findings. When this happens, misrepresentation of the literature and subsequent inappropriate decisions may result. We aimed to examine the factors associated with the time to publication of Cochrane reviews. METHODS: Review protocols published in issue 2, 2000, of the Cochrane Database of Systematic Reviews were included in this analysis if the corresponding review was published by issue 1, 2008. We used univariable and multivariate analyses to examine the time from publication of the protocol to publication of the first review and review-related factors predicting the time to publication. RESULTS: Of 118 eligible protocols published in issue 2, 2000, we identified 93 Cochrane reviews that had been published by January 2008. Of these, 36 (39%) were updates. The median time to publication was 1.63 years (range 0.15-7.31 years). A change in authors between publication of the protocol and publication of the final review was associated with longer time to publication (p = 0.002), whereas updated reviews were associated with shorter time to publication (p = 0.030). INTERPRETATION: In our study, 79% of the Cochrane protocols were published as a final review, and some Cochrane reviews took over 7 years from publication of the protocol to publication of the final review. Strategies to increase the number of published Cochrane reviews and decrease the time to publication should be considered, such as providing support to reviewers when a change in authorship occurs.

13.
Diab Vasc Dis Res ; 6(4): 276-82, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20368222

RESUMO

We examined the association between heart rate variability (HRV) and duration of type 2 diabetes among 155 female and 106 male subjects: mean+/-SD for duration=49.6+/-65.6 and 57.3+/-77.1 months, respectively, p=0.38. Among males, duration of diabetes was independently and inversely associated with vagal-heart rate modulation (high frequency (HF) power, 0.15-0.40 Hz, standardised ss = -0.32, p=0.001; root mean square of successive differences between R-R intervals, ss = -0.26, p=0.006) and total R-R variability (standard deviation of normal R-R intervals, ss = -0.36, p=0.001); but not among females (p> or =0.80 for each HRV index). In contrast, HF was inversely associated with age of diabetes diagnosis (ss = -0.16, p=0.04) and 10-year absolute risk for coronary heart disease (ss = -0.16, p=0.04) among female subjects. Longitudinal research is needed to establish whether risk factors for early cardiac autonomic impairment differ among men and women with type 2 diabetes.


Assuntos
Doença das Coronárias/etiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Frequência Cardíaca , Coração/inervação , Nervo Vago/fisiopatologia , Adulto , Fatores Etários , Idoso , Distribuição de Qui-Quadrado , Doença das Coronárias/fisiopatologia , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Eletrocardiografia , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Ontário , Medição de Risco , Fatores de Risco , Fatores Sexuais , Fatores de Tempo
14.
Transplantation ; 87(5): 719-25, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19295317

RESUMO

BACKGROUND: Cytomegalovirus (CMV), human herpesvirus-6 and -7 (HHV-6 and -7) are beta-herpesviruses that commonly reactivate and have been proposed to trigger acute rejection and chronic allograft injury. We assessed the contribution of these viruses in the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation. METHODS: Quantitative real-time polymerase chain reaction of bronchoalveolar lavage samples were performed for CMV, HHV-6 and -7 in a prospective cohort of lung transplant recipients. A time-dependent Cox regression analysis was used to correlate the risk of BOS and acute rejection in patients with and without beta-herpesviruses infection. RESULTS: Ninety-three patients were included in the study over a period of 3 years. A total of 581 samples from bronchoalveolar lavage were obtained. Sixty-one patients (65.6%) had at least one positive result for one of the beta-herpesviruses: 48 patients (51.6%) for CMV and 19 patients (20.4%) for both HHV-6 and -7. Median peak viral load was 3419 copies/mL for CMV, 258 copies/mL for HHV-6, and 665 copies/mL for HHV-7. Acute rejection (>or=grade 2) occurred in 46.2% and BOS (>or=stage 1) in 19.4% of the patients. In the Cox regression model the relative risk of acute rejection or BOS was not increased in patients with any beta-herpesviruses reactivation. Acute rejection was the only independently associated risk factor for BOS. CONCLUSIONS: In lung transplant recipients receiving prolonged antiviral prophylaxis, reactivation of beta-herpesviruses within the allograft was common. However, despite high viral loads in many patients, virus replication was not associated with the development of rejection or BOS.


Assuntos
Antivirais/uso terapêutico , Bronquiolite Obliterante/epidemiologia , Bronquiolite Obliterante/cirurgia , Infecções por Citomegalovirus/prevenção & controle , Transplante de Pulmão/efeitos adversos , Adulto , Antifúngicos/uso terapêutico , Bronquiolite Obliterante/complicações , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/epidemiologia , Quimioterapia Combinada , Feminino , Ganciclovir/análogos & derivados , Ganciclovir/uso terapêutico , Rejeição de Enxerto/epidemiologia , Herpesvirus Humano 6/isolamento & purificação , Herpesvirus Humano 7/isolamento & purificação , Humanos , Imunossupressores/uso terapêutico , Transplante de Pulmão/imunologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Pirimidinas/uso terapêutico , Síndrome , Triazóis/uso terapêutico , Valganciclovir , Voriconazol
15.
PLoS One ; 3(11): e3684, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18997866

RESUMO

BACKGROUND: Cochrane reviews are regarded as being scientifically rigorous and are increasingly used by a variety of stakeholders. However, factors predicting the publication of Cochrane reviews have never been reported. This is important because if a higher proportion of Cochrane protocols with certain characteristics (e.g., funding) are being published, this may lead to inaccurate decisions. We examined the frequency of published and unpublished Cochrane reviews and protocol factors that predict the publication of Cochrane reviews. METHODOLOGY/PRINCIPAL FINDINGS: Retrospective cohort study of Cochrane protocols published in 2000 (Issues 2 to 4) and 2001 (Issue 1). The publication status of these reviews was followed up to Issue 1, 2008 in The Cochrane Library. Survival analysis of the time from protocol publication to the first review publication and protocol factors predicting the time to publication was conducted. There were 411 new Cochrane protocols in the cohort. After excluding 39; 71/372 (19.1%) were unpublished and 301/372 (80.9%) were published as full Cochrane reviews at the time of study analysis (January 2008). The median time to publication was 2.4 years (range: 0.15 to 8.96). Multivariate analyses revealed that shorter time to publication was associated with the review subsequently being updated (hazard ratio, HR: 1.80 [95% confidence interval, CI: 1.39 to 2.33 years]) and longer time to publication was associated with the review having two published protocols, indicating changes to the review plan (HR: 0.33 [95% CI: 0.12 to 0.90 years]). CONCLUSIONS/SIGNIFICANCE: Only about 80% Cochrane protocols were published as full reviews after over 8 years of follow-up. The median time to publication was 2.4 years and some reviews took much longer. Strategies to decrease time to publication should be considered, such as streamlining the review process, increased support for authors when protocol amendments occur, and better infrastructure for updating Cochrane reviews.


Assuntos
Editoração , Literatura de Revisão como Assunto , Estudos de Coortes , Medicina Baseada em Evidências , Humanos , Viés de Publicação , Editoração/normas , Editoração/estatística & dados numéricos , Estudos Retrospectivos
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