Home About us Contact
|
Home About us Contact | ||
|
|
||
Methodological Shortcomings (methodological + shortcoming)
Selected AbstractsPsycho-educational interventions for children and young people with Type 1 diabetesDIABETIC MEDICINE, Issue 9 2006H. R. Murphy Abstract Background, A systematic review of the literature in 2000 revealed numerous methodological shortcomings in education research, but in recent years progress has been made in the quantity and quality of psycho-educational intervention studies. Summary of contents, This review focuses on diabetes education programmes developed for children, young people and their families in the past 5 years. A comprehensive review of the literature identified 27 articles describing the evaluation of 24 psycho-educational interventions. Data summary tables compare the key features of these, and comparisons are made between individual, group and family-based interventions. Effect sizes are calculated for nine of the randomized studies. Three research questions are posed: firstly has the recent literature addressed the problems highlighted in the previous review; secondly is there sufficient evidence to recommend adaptation of a particular programme; and, finally, what do we still need to do? Conclusions, Progress in the quality and quantity of educational research has not resulted in improved effectiveness of interventions. There is still insufficient evidence to recommend adaptation of a particular educational programme and no programme that has been proven effective in randomized studies for those with poor glycaemic control. To develop a range of effective educational interventions, further research involving larger sample sizes with multicentre collaboration is required. [source] Recreational ecstasy use and the neurotoxic potential of MDMA: current status of the controversy and methodological issuesDRUG AND ALCOHOL REVIEW, Issue 3 2006MICHAEL LYVERS Abstract The controversy over possible MDMA-induced serotonergic neurotoxicity in human recreational ecstasy users is examined critically in light of recent research findings. Although the designs of such studies have improved considerably since the 1990s, the evidence to date remains equivocal for a number of reasons, including (1) inconsistent findings on the existence and reversibility of persistent ecstasy-related serotonergic and cognitive deficits; (2) lack of clear association between changes in brain imaging measures and functional deficits attributed to MDMA-induced neurotoxicity; (3) the contribution of concomitant cannabis or other drug use to both brain imaging abnormalities and cognitive deficits; (4) methodological shortcomings such as failure to adequately match samples of ecstasy users and controls; (5) the questionable relevance of animal models of MDMA-induced neurotoxicity to typical human patterns of ecstasy use; and (6) the potential role of inherent pre-drug deficits in serotonergic systems, impulse control and executive cognitive function that may predispose to excessive use of drugs including ecstasy. Given the retrospective nature of nearly all studies of ecstasy users to date, the controversy over whether MDMA has ever caused neurotoxicity or cognitive deficit in human ecstasy users is likely to continue for some time without resolution. [source] The costs and benefits of fast livingECOLOGY LETTERS, Issue 12 2009Karen E. Rose Abstract Growth rates play a fundamental role in many areas of biology (Q. Rev. Biol., 67, 1992, 283; Life History Invariants. Some Explorations of Symmetry in Evolutionary Biology, 1993; Philos. Trans. R. Soc. Lond. B Biol. Sci., 351, 1996, 1341; Plant Strategies, Vegetation Processes, and Ecosystem Properties, 2002; Trends Ecol. Evol., 18, 2003, 471; Q. Rev. Biol., 78, 2003, 23; J. Ecol., 95, 2007, 926.) but the cost and benefits of different growth rates are notoriously difficult to quantify (Q. Rev. Biol., 72, 1997, 149; Funct. Ecol., 17, 2003, 328). This is because (1) growth rate typically declines with size and yet the most widely used growth measure , relative growth rate or RGR (conventionally measured as the log of the ratio of successive sizes divided by the time interval) , is not size-corrected and so confounds growth and size, (2) organisms have access to different amounts of resource and (3) it is essential to allow for the long-term benefits of larger size. Here we experimentally demonstrate delayed costs and benefits of rapid growth in seven plant species using a novel method to calculate size-corrected RGR. In control treatments, fast-growing plants benefited from increased reproduction the following year; however, fast-growing plants subjected to an experimental stress treatment (defoliation) showed strongly reduced survival and reproduction the following year. Importantly, when growth was estimated using the classical RGR measure, no costs or benefits were found. These results support the idea that life-history trade-offs have a dominant role in life-history and ecological theory and that the widespread failure to detect them is partly due to methodological shortcomings. Ecology Letters (2009) 12: 1379,1384 [source] State-of-the-art methodologies in alcohol-related health services researchADDICTION, Issue 11s3 2000Harold I. Perl Many of the failures to replicate clinical findings of treatment efficacy in more realistic field and community settings can be attributed to inappropriate research designs and other methodological shortcomings. In order to increase research designers' awareness of existing methodologies that may be better suited to answer the critical questions inherent in health services research on alcohol-related issues, the National Institute on Alcohol Abuse and Alcoholism (NIAAA) convened an expert conference with three specific goals: (1) to identify the critical issues involved in alcohol services research; (2) to develop a primer that explicated each key area; and (3) to compile the resulting primers into an accessible resource for researchers, policy makers and consumers. The 9 papers in this special supplement are the product of that conference and are organized broadly around three phases of the research process: study design and implementation, data collection and use, and the analysis and interpretation of data. A final summary paper discusses the issues and offers a synthesis of key themes as well as some direction for the future. [source] Headache and Psychological Functioning in Children and AdolescentsHEADACHE, Issue 9 2006Scott W. Powers PhD Headache can affect all aspects of a child's functioning, leading to negative affective states (eg, anxiety, depression, anger) and increased psychosocial problems (for instance, school absences, problematic social interactions). For children and adolescents who experience frequent headache problems, comorbid psychological issues are a well-recognized, but poorly understood, clinical phenomenon. The confusion surrounding the relationship between pediatric headache and psychopathology exists for several reasons. First, in some cases, headache has been inappropriately attributed to psychological or personality features based on anecdotal observations or interpretations that go beyond the available data. Additionally, measures of psychopathology have not always adhered to the American Psychiatric Association's diagnostic criteria, thus reducing the reliability of diagnostic judgments. Furthermore, the diagnosis of headache has not always followed standard criteria, and has been complicated by the emergence of new terms and evolving measures. Finally, methodological shortcomings, such as incomplete descriptions of the procedures and criteria used for the study, inadequate descriptions of headache severity, lack of a control group for comparison with individuals without headaches, reliance primarily on cross-sectional research designs that are often discussed with inferences to causal hypotheses, and the use of unstandardized assessment measures, have significantly limited the validity of research findings. The goal of the current review is to examine the extant literature to provide the most up-to-date picture on what the research has made available about the magnitude, specificity, and causes of psychopathology in children and adolescents with headache, in an effort to further elucidate their relationship and prompt a more methodologically rigorous study of these issues. [source] Cost-effectiveness analysis based on the number-needed-to-treat: common sense or non-sense?HEALTH ECONOMICS, Issue 1 2004Ivar Sønbø Kristiansen Abstract This paper explores and critically discusses some of the methodological limitations of using the number-needed-to-treat (NNT) in economic evaluation. We argue that NNT may be a straightforward measure of benefit when the effect of an intervention is immediate, but that serious problems arise when the effect is delay rather than avoidance of an adverse event. In this case, NNT is not a robust or accurate measure of effect, but will vary considerably and inconsistently over time. This weakness will naturally spill over onto any CEA based on NNT. A literature review demonstrated that CEAs based on NNT were all published within the last five years, and that all studies suffered from important limitations. A major weakness of using NNT is the imposed restrictions on the outcome measure, which can only be strictly uni-dimensional and non-generic. Using NNT in economic evaluations is obtained at a cost in terms of both methodological shortcomings, and a reduced ability for such evaluations to serve as a useful tool in decision making processes. The use of NNT in economic evaluations might be better avoided. To every complicated question, there is a simple, straightforward, easy , and probably wrong answer (Occam's Sledgehammer). Copyright © 2003 John Wiley & Sons, Ltd. [source] Centenarians , a useful model for healthy aging?AGING CELL, Issue 3 2009A 29-year follow-up of hospitalizations among 40 000 Danes born in 190 Summary Centenarians surpass the current human life expectancy with about 20,25 years. However, whether centenarians represent healthy aging still remains an open question. Previous studies have been hampered by a number of methodological shortcomings such as a cross-sectional design and lack of an appropriate control group. In a longitudinal population-based cohort, it was examined whether the centenarian phenotype may be a useful model for healthy aging. The study was based on a complete follow up of 39 945 individuals alive in the Danish 1905 birth cohort on January 1, 1977 identified through the Danish Civil Registration System (DCRS). Data from the Danish Demographic Database and The Danish National Patient Register (in existence since 1977) were used. The 1905 cohort was followed up from 1977 through 2004 with respect to hospitalizations and number of hospital days. Survival status was available until December 2006. Danish centenarians from the 1905 cohort were hospitalized substantially less than their shorter-lived contemporaries at the same point in time during the years 1977 through 2004. For example, at age 71,74, the proportion of nonhospitalized centenarians was 80.5% compared with 68.4% among individuals who died in their early 80s. This trend was evident in both sexes. As a result of their lower hospitalization rates and length of stay in hospital compared with their contemporaries, who died at younger ages, Danish centenarians represent healthy agers. Centenarians constitute a useful study population in the search for fixed traits associated with exceptional longevity, such as genotype. [source] Interpreting interactions between treatments that slow agingAGING CELL, Issue 1 2002David Gems Summary A major challenge in current research into aging using model organisms is to establish whether different treatments resulting in slowed aging involve common or distinct mechanisms. Such treatments include gene mutation, dietary restriction (DR), and manipulation of reproduction, gonadal signals and temperature. The principal method used to determine whether these treatments act through common mechanisms is to compare the magnitude of the effect on aging of each treatment separately with that when two are applied simultaneously. In this discussion we identify five types of methodological shortcomings that have marred such studies. These are (1) submaximal lifespan-extension by individual treatments, e.g. as a result of the use of hypomorphic rather than null alleles; (2) effects of a single treatment on survival through more than one mechanism, e.g. pleiotropic effects of lifespan mutants; (3) the difficulty of interpreting the magnitude of increases in lifespan in double treatments, and failure to measure and model age-specific mortality rates; (4) the non-specific effects of life extension suppressors; and (5) the possible occurrence of artefactual mutant interactions. When considered in the light of these problems, the conclusions of a number of recent lifespan interaction studies appear questionable. We suggest six rules for avoiding the pitfalls that can beset interaction studies. [source] Barriers to Managing Diversity in a UK Constabulary: The Role of DiscourseJOURNAL OF MANAGEMENT STUDIES, Issue 7 2002Penny Dick The literature on diversity management has tended to obfuscate some of the theoretical and methodological shortcomings associated with research in this area. Specifically, the literature tends to make a number of rather naïve assumptions about the experiences and aspirations of disadvantaged groups. This paper seeks to problematize the universalist and partisan tendencies that typify much of the diversity literature by focusing on the issue of ,resistance'. Using a form of discourse analysis informed by Foucauldian principles, the paper explores how ,resistance' to diversity initiatives is expressed by both ,dominant' and ,subordinated' groups in a UK police force. It is argued that ,resistance' is better thought of as a discursive resource that can be drawn upon to justify or account for one's own organizational experiences and, in turn, the need to both justify and account for one's experiences is located in broader discursive fields that reproduce dominant ideologies of liberal democracies. The theoretical implications of this position are discussed and a case is presented for more critical and theoretical approaches in the diversity management literature. [source] The ,ghosts' that pester studies on learning in mosquitoes: guidelines to chase them offMEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2006W. J. ALONSO Abstract The identification of memory and learning in medically important mosquito species has been of epidemiological interest mainly because of the implications of learning on the pattern of contact between vectors and hosts. Empirical results either showing or suggesting the existence of cognitive abilities in mosquitoes have been reported in a number of experimental studies, mainly based on the observation of individual fidelity towards subsets of specific resources, such as hosts, resting sites or breeding sites. A closer inspection of the design of these experiments shows that, with the exception of recent studies providing stronger evidence of learning in the genus Culex (Diptera: Culicidae), methodological shortcomings still hinder the possibility of eliminating alternative interpretations for these findings, in some cases because the experiments were not specifically designed to identify the phenomenon, but mostly because of a lack of appropriate controls or replication. By highlighting these limitations, while acknowledging the practical difficulties that are inherent to the field, we aim to help expel from future research the ,ghosts' that still preclude the achievement of more definite conclusions about the prevalence of memory and learning in this group of insects. [source] Psychological interventions with siblings of pediatric cancer patients: a systematic reviewPSYCHO-ONCOLOGY, Issue 12 2009Alice Prchal Abstract Objective: Siblings of pediatric cancer patients have been shown to be at risk for developing emotional, behavioral, and social problems. There is a need for psychological interventions in this population. Several researchers have previously documented and evaluated their interventions with siblings. This paper aimed at reviewing the existing reports of evaluated psychological interventions with siblings of pediatric cancer patients and at outlining future directions. Methods: Research was conducted on several online bibliographic databases. Articles were selected on the basis of predefined criteria. If possible, effect sizes (ES) were calculated. Results: Fourteen studies representing 11 different sibling interventions met criteria for inclusion. One individual intervention, three camps, and seven groups were found. Objectives of interventions concentrated mainly on enhancing siblings' coping and improving their medical knowledge. In terms of outcome measures, most of the studies focused on psychological adjustment variables. Findings showed significant improvements in siblings' depression symptomatology, medical knowledge, and health-related quality of life. Findings were inconsistent with regard to anxiety, behavioral problems, social adjustment, self-esteem, and posttraumatic stress symptoms. Depending on the outcome variables, small to large ES were found. Satisfaction with the intervention was high in both siblings and parents. Conclusion: There is tentative evidence that psychological interventions with siblings of childhood cancer patients can effectively reduce psychological maladjustment and improve medical knowledge about cancer. However, the number of studies is small, and several methodological shortcomings have to be noted. In future, more randomized controlled trials need to be conducted in larger samples to extend the evidence base. Copyright © 2009 John Wiley & Sons, Ltd. [source] Annotation: Neurofeedback , train your brain to train behaviourTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 1 2007Hartmut Heinrich Background:, Neurofeedback (NF) is a form of behavioural training aimed at developing skills for self-regulation of brain activity. Within the past decade, several NF studies have been published that tend to overcome the methodological shortcomings of earlier studies. This annotation describes the methodical basis of NF and reviews the evidence base for its clinical efficacy and effectiveness in neuropsychiatric disorders. Methods:, In NF training, self-regulation of specific aspects of electrical brain activity is acquired by means of immediate feedback and positive reinforcement. In frequency training, activity in different EEG frequency bands has to be decreased or increased. Training of slow cortical potentials (SCPs) addresses the regulation of cortical excitability. Results:, NF studies revealed paradigm-specific effects on, e.g., attention and memory processes and performance improvements in real-life conditions, in healthy subjects as well as in patients. In several studies it was shown that children with attention-deficit hyperactivity disorder (ADHD) improved behavioural and cognitive variables after frequency (e.g., theta/beta) training or SCP training. Neurophysiological effects could also be measured. However, specific and unspecific training effects could not be disentangled in these studies. For drug-resistant patients with epilepsy, significant and long-lasting decreases of seizure frequency and intensity through SCP training were documented in a series of studies. For other child psychiatric disorders (e.g., tic disorders, anxiety, and autism) only preliminary investigations are available. Conclusions:, There is growing evidence for NF as a valuable treatment module in neuropsychiatric disorders. Further, controlled studies are necessary to establish clinical efficacy and effectiveness and to learn more about the mechanisms underlying successful training. [source] Intergroup attribution bias in the context of extreme intergroup conflictASIAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 4 2009Amarina Ariyanto Limited research has examined attributional biases in the context of extreme intergroup conflict, and the research that does exist contains methodological shortcomings. To remedy this, 282 Indonesians read a newspaper article describing a violent incident in Ambon. Christians (but not Muslims) used stronger situational attributions for violent ingroup acts than for violent outgroup acts. In contrast, both Muslims and Christians used stronger dispositional attributions for violent outgroup acts than for violent ingroup acts. This latter tendency emerged independently of who was described in the article as the perpetrators of the violence. Implications for our understanding of intergroup conflict are discussed. [source] | ||||||||||||||||