Weight of evidence

Evidence-based Medicine (EBM) has become a major source of medical knowledge. It handles complexities of virtually every method or technique used in research. The knowledge on how the EBM researcher retrieves information, judges for relevance and analyzes derived data is invaluable for the skillful reader of medical scientific reports.

Using household survey data to inform policy decisions regarding the delivery of evidence-based parenting interventions.

Background: This study used household survey data on the prevalence of child, parent and family variables to establish potential targets for a population-level intervention to strengthen parenting skills in the community. The goals of the intervention include decreasing child conduct problems, increasing parental self-efficacy, use of positive parenting strategies, decreasing coercive parenting and increasing help-seeking, social support and participation in positive parenting programmes. Methods: A total of 4010 parents with a child under the age of 12 years completed a statewide telephone survey on parenting. Results: One in three parents reported that their child had a behavioural or emotional problem in the previous 6 months. Furthermore, 9% of children aged 2–12 years meet criteria for oppositional defiant disorder. Parents who reported their child's behaviour to be difficult were more likely to perceive parenting as a negative experience (i.e. demanding, stressful and depressing). Parents with greatest difficulties were mothers without partners and who had low levels of confidence in their parenting roles. About 20% of parents reported being stressed and 5% reported being depressed in the 2 weeks prior to the survey. Parents with personal adjustment problems had lower levels of parenting confidence and their child was more difficult to manage. Only one in four parents had participated in a parent education programme. Conclusions: Implications for the setting of population-level goals and targets for strengthening parenting skills are discussed.

Perceptions of evidence-based practice: A survey of Australian occupational therapists

Evidence-based practice (EBP) requires clinicians to access, appraise and integrate research literature with clinical experience and clients' perspectives. Currently, little is known about occupational therapists' attitudes to EBP, their perception of implementation barriers or their educational needs. A questionnaire reflecting these issues was sent to a proportionate random sample of 1491 members of the national professional occupational therapy association, OT AUSTRALIA. The questionnaire was completed by 649 (44%) participants. Occupational therapists were positive about EBP with most (96%) agreeing that EBP is important to occupational therapy. Although 56% used research to make clinical decisions, more relied on clinical experience (96%), information from continuing education (82%) and colleagues (80%). Lack of time, evidence and skills were identified as the main barriers to the implementation of EBP. Over half (52%) expressed strong interest in EBP skills training, and most (80%) indicated an interest in the availability of brief summaries of evidence. Targeted educational initiatives, resources and systems are needed to support EBP in occupational therapy.

Introducing OTseeker (Occupational Therapy Systematic Evaluation of Evidence): A new evidence database for occupational therapists

OTseeker (Occupational Therapy Systematic Evaluation of Evidence) is a new resource for occupational therapists that has been designed with the principle aim of increasing access to research to support clinical decisions. It contains abstracts of systematic reviews and quality ratings of randomized controlled trials (RCTs) relevant to occupational therapy. It is available, free of charge, at www.otseeker.com. This paper describes the OTseeker database and provides an example of how it may support occupational therapy practice.

Infection and childhood leukemia: review of evidence

OBJECTIVE : To analyze studies that evaluated the role of infections as well as indirect measures of exposure to infection in the risk of childhood leukemia, particularly acute lymphoblastic leukemia. METHODS : A search in Medline, Lilacs, and SciELO scientific publication databases initially using the descriptors “childhood leukemia” and “infection” and later searching for the words “childhood leukemia” and “maternal infection or disease” or “breastfeeding” or “daycare attendance” or “vaccination” resulted in 62 publications that met the following inclusion criteria: subject aged ≤ 15 years; specific analysis of cases diagnosed with acute lymphoblastic leukemia or total leukemia; exposure assessment of mothers’ or infants’ to infections (or proxy of infection), and risk of leukemia. RESULTS : Overall, 23 studies that assessed infections in children support the hypothesis that occurrence of infection during early childhood reduces the risk of leukemia, but there are disagreements within and between studies. The evaluation of exposure to infection by indirect measures showed evidence of reduced risk of leukemia associated mainly with daycare attendance. More than 50.0% of the 16 studies that assessed maternal exposure to infection observed increased risk of leukemia associated with episodes of influenza, pneumonia, chickenpox, herpes zoster, lower genital tract infection, skin disease, sexually transmitted diseases, Epstein-Barr virus, and Helicobacter pylori . CONCLUSIONS : Although no specific infectious agent has been identified, scientific evidence suggests that exposure to infections has some effect on childhood leukemia etiology.

Treatment of American tegumentary leishmaniasis in special populations: a summary of evidence

We aimed to assess and synthesize the information available in the literature regarding the treatment of American tegumentary leishmaniasis in special populations. We searched MEDLINE (via PubMed), EMBASE, LILACS, SciELO, Scopus, Cochrane Library and mRCT databases to identify clinical trials and observational studies that assessed the pharmacological treatment of the following groups of patients: pregnant women, nursing mothers, children, the elderly, individuals with chronic diseases and individuals with suppressed immune systems. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. The available evidence suggests that the treatments of choice for each population or disease entity are as follows: nursing mothers and children (meglumine antimoniate or pentamidine), patients with renal disease (amphotericin B or miltefosine), patients with heart disease (amphotericin B, miltefosine or pentamidine), immunosuppressed patients (liposomal amphotericin), the elderly (meglumine antimoniate), pregnant women (amphotericin B) and patients with liver disease (no evidence available). The quality of evidence is low or very low for all groups. Accurate controlled studies are required to fill in the gaps in evidence for treatment in special populations. Post-marketing surveillance programs could also collect relevant information to guide treatment decision-making.

Lack of evidence for human infection with Xenotropic murine leukemia virus-related virus in the Brazilian Amazon basin

Introduction This study confirmed the absence of natural infection with Xenotropic murine leukemia virus-related virus (XMRV) or XMRV-related disease in human populations of the Brazilian Amazon basin. We demonstrated that 803 individuals of both sexes, who were residents of Belem in the Brazilian State of Pará, were not infected with XMRV. Methods Individuals were divided into 4 subgroups: healthy individuals, individuals infected with human immunodeficiency virus, type 1 (HIV-1), individuals infected with human T-lymphotrophic virus, types 1 or 2 (HTLV-1/2), and individuals with prostate cancer. XMRV infection was investigated by nested PCR to detect the viral gag gene and by quantitative PCR to detect pol. Results There was no amplification of either gag or pol segments from XRMV in any of the samples examined. Conclusions This study supports the conclusions of the studies that eventually led to the retraction of the original study reporting the association between XMRV and human diseases.

Rifapentine for latent tuberculosis infection treatment in the general population and human immunodeficiency virus-positive patients: summary of evidence

AbstractLatent tuberculosis infection (LTBI) and human immunodeficiency virus (HIV)-coinfection are challenges in the control of tuberculosis transmission. We aimed to assess and summarize evidence available in the literature regarding the treatment of LTBI in both the general and HIV-positive population, in order to support decision making by the Brazilian Tuberculosis Control Program for LTBI chemoprophylaxis. We searched MEDLINE, Cochrane Library, Centre for Reviews and Dissemination, Embase, LILACS, SciELO, Trip database, National Guideline Clearinghouse, and the Brazilian Theses Repository to identify systematic reviews, randomized clinical trials, clinical guidelines, evidence-based synopses, reports of health technology assessment agencies, and theses that investigated rifapentine and isoniazid combination compared to isoniazid monotherapy. We assessed the quality of evidence from randomized clinical trials using the Jadad Scale and recommendations from other evidence sources using the Grading of Recommendations, Assessment, Development, and Evaluations approach. The available evidence suggests that there are no differences between rifapentine + isoniazid short-course treatment and the standard 6-month isoniazid therapy in reducing active tuberculosis incidence or death. Adherence was better with directly observed rifapentine therapy compared to self-administered isoniazid. The quality of evidence obtained was moderate, and on the basis of this evidence, rifapentine is recommended by one guideline. Available evidence assessment considering the perspective of higher adherence rates, lower costs, and local peculiarity context might support rifapentine use for LTBI in the general or HIV-positive populations. Since novel trials are ongoing, further studies should include patients on antiretroviral therapy.

Lack of evidence of the interaction of the Aß peptide with the Wnt signaling cascade in Drosophila models of Alzheimer's disease.

Background Alzheimer's disease (AD) is the leading form of dementia worldwide. The Aß-peptide is believed to be the major pathogenic compound of the disease. Since several years it is hypothesized that Aß impacts the Wnt signaling cascade and therefore activation of this signaling pathway is proposed to rescue the neurotoxic effect of Aß. Findings Expression of the human Aß42 in the Drosophila nervous system leads to a drastically shortened life span. We found that the action of Aß42 specifically in the glutamatergic motoneurons is responsible for the reduced survival. However, we find that the morphology of the glutamatergic larval neuromuscular junctions, which are widely used as the model for mammalian central nervous system synapses, is not affected by Aß42 expression. We furthermore demonstrate that genetic activation of the Wnt signal transduction pathway in the nervous system is not able to rescue the shortened life span or a rough eye phenotype in Drosophila. Conclusions Our data confirm that the life span is a useful readout of Aß42 induced neurotoxicity in Drosophila; the neuromuscular junction seems however not to be an appropriate model to study AD in flies. Additionally, our results challenge the hypothesis that Wnt signaling might be implicated in Aß42 toxicity and might serve as a drug target against AD.

Activity in inferior parietal and medial prefrontal cortex signals the accumulation of evidence in a probability learning task.

In an uncertain environment, probabilities are key to predicting future events and making adaptive choices. However, little is known about how humans learn such probabilities and where and how they are encoded in the brain, especially when they concern more than two outcomes. During functional magnetic resonance imaging (fMRI), young adults learned the probabilities of uncertain stimuli through repetitive sampling. Stimuli represented payoffs and participants had to predict their occurrence to maximize their earnings. Choices indicated loss and risk aversion but unbiased estimation of probabilities. BOLD response in medial prefrontal cortex and angular gyri increased linearly with the probability of the currently observed stimulus, untainted by its value. Connectivity analyses during rest and task revealed that these regions belonged to the default mode network. The activation of past outcomes in memory is evoked as a possible mechanism to explain the engagement of the default mode network in probability learning. A BOLD response relating to value was detected only at decision time, mainly in striatum. It is concluded that activity in inferior parietal and medial prefrontal cortex reflects the amount of evidence accumulated in favor of competing and uncertain outcomes.