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1.
In this era of evidence-based medicine, diagnostic tests cannot escape close scrutiny of their effectiveness. Sensitivity and specificity have up till now played a central role in the evaluation of diagnostic tests. These terms are not without their shortcomings when it comes to the characterisation of a test's true worth for patients. Randomised clinical trials are increasingly used for evaluation of medical tests and outlining of strategy. The indirect relationship between test results and health outcome creates additional challenges for designers of such trials.  相似文献   

2.
The results of subgroup analyses can be very informative, in particular for clinicians interested in evidence pertaining most directly to a particular patient. However, subgroup analyses may also be potentially misleading. The strength of evidence for subgroup effects depends on the question whether hypotheses have been defined prior to analysis, whether potential problems regarding multiple comparisons have been considered and whether there is biological plausibility of the effects. Using these guidelines the reader of a trial report should be able to decide if presented subgroup effects are of clinical importance or if the overall result is a better estimate of treatment effect.  相似文献   

3.
A pilot study is often performed before the start of a large study. Its aim is improving the methodological quality and evaluating the feasibility. The results of a pilot study are also often used to gain an impression of the efficacy of an intervention. For this purpose a pilot is absolutely unsuited. However, the estimate of the effect of an intervention in small studies such as pilot studies is determined to a large extent by chance. When conducting small studies the chance of publication bias is large. Small studies of adequate methodological quality should be published, whether the results are positive or negative, significant or non-significant, because combination in a later cumulative meta-analysis may lead to sufficient power to assess the efficacy of an experimental intervention.  相似文献   

4.
Some argue that the high heritability of IQ renders purely environmental explanations for large IQ differences between groups implausible. Yet, large environmentally induced IQ gains between generations suggest an important role for environment in shaping IQ. The authors present a formal model of the process determining IQ in which people's IQs are affected by both environment and genes, but in which their environments are matched to their IQs. The authors show how such a model allows very large effects for environment, even incorporating the highest estimates of heritability. Besides resolving the paradox, the authors show that the model can account for a number of other phenomena, some of which are anomalous when viewed from the standard perspective. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

5.
This study investigated a broad array of putative risk factors for the onset of major depression and examined their screening properties in a longitudinal study of 479 adolescent girls. Results indicated that the most potent predictors of major depression onset included subthreshold depressive symptoms, poor school and family functioning, low parental support, bulimic symptoms, and delinquency. Classification tree analysis revealed interactions between 4 of these predictors, suggesting qualitatively different pathways to major depression. Girls with the combination of elevated depressive symptoms and poor school functioning represented the highest risk group, with a 40% incidence of major depression during the ensuing 4-year period. Results suggest that selected and indicated prevention programs should target these high-risk populations and seek to reduce these risk factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

6.
7.
This article describes an evidence-based preventive group intervention, Incredible Years Parent Training Program (IY). Decades of research have shown that IY strengthens parent and child competencies and in turn reduces child risks for developing conduct problems and other negative life outcomes. The purpose of this article is to examine IY through a resilience lens and highlight how it capitalizes on group process mechanisms to serve as a model preventive group intervention. Future directions and implications for research, practice, and training are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

8.
Research has demonstrated that high, but not low caffeine users exhibit an attentional bias to caffeine related stimuli. Separately, the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) has been used to investigate the valence of implicit cognitions to drugs with some contradictory findings, though no work has addressed this issue with respect to caffeine. Here, we examined whether attentional bias would be found in high and moderate caffeine users using a pictorial version of the dot-probe task. A second aim was to explore differences in implicit cognitions between users and non-users. Fifteen high, moderate and non-caffeine users completed a picture dot-probe, IAT, and mood questionnaire following overnight caffeine deprivation. In the IAT, results demonstrated positive associations to caffeine related words for high but not moderate or non-users. Lower ratings for calmness were evident in both groups of caffeine compared to non-users. Dot-probe findings revealed an attentional bias among moderate caffeine users and non-users but not heavy users. The observed positive implicit associations to caffeine suggest that drug acceptability is the key in such perceptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

9.
Event-related potential (ERP) and cued-recall performance were used to investigate the influence of (a) context, (b) repeating a word's meaning to word repetition priming, and (c) repetition on the ERP difference related to memory (Dm). Sentences ended with either nonhomographs or homographs. For nonhomographs, either the sentence context, the final word, both, or neither were repeated. Homographs were repeated in their original context or in new sentences that biased the same or an alternative meaning. Large repetition effects were found for all words repeated in their original contexts; in contrast, changing contexts led to no repetition effects whether the meaning of the repeated words was preserved or not. These results favor an episodic contribution to word repetition priming and suggest a common process for Dm and repetition.  相似文献   

10.
Investigated the influence of trivial testimonial detail on judgments of 424 undergraduates who served as mock jurors. Ss read a summary of a court case involving robbery and murder. In Experiment 1, detailed testimony influenced judgments of guilt, even when the detail was unrelated to the culprit. In Experiment 2, detailed testimony was especially powerful when an opposing witness testified that she could not remember the trivial details. Subsequent analyses suggest that the impact of detailed testimony on guilt judgments is mediated by inferences about the eyewitnesses. When eyewitnesses provided more detail, they were generally judged to be more credible, to have a better memory for the culprit's face and for details, and to have paid more attention to the culprit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

11.
Recently a randomised placebo controlled trial in a general practice setting showed that inhaler therapy with a spacer device in 218 1-4 year old children with moderate asthma is feasible, but that treatment with cromoglycate was no more effective than placebo. The lack of benefit from the treatment with cromoglycate may have resulted from several points discussed and refuted in this commentary. Major points are the degree of asthma of the children and uncertainty about the amount of medication that reached the lungs. The results of the trial support the intentions of national and international guidelines to withdraw the recommendation of cromoglycate as the first choice in prophylactic asthma treatment.  相似文献   

12.
Conducted an exploratory content analysis of 20 pairs of taped telephone calls to a suicide prevention and crisis service. Variables that might differentiate between referrals resulting in "show" and those resulting in "no show," were studied. A show and a no show call for each of 20 telephone therapists were coded. It is concluded that a scale based on 6 indexes would differentiate between the 2 groups. Motivation of the caller for getting help and the concreteness of the therapist emerged as most important factors in the 6-item scale. The relationship between this research and a crisis intervention model is discussed. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
After studies which have mapped the gamma-sarcoglycan deficient limb-girdle muscular dystrophy (LGMD2C) to chromosome 13q12 and recent identification of mutations within this gene, prenatal diagnosis has become possible. The deletion of exon 5 in the gamma-sarcoglycan gene was found in a consanguineous family and prenatal diagnosis was successfully provided. This is the first prenatal diagnosis of LGMD2C.  相似文献   

14.
Forty-three patients with spastic quadriplegia (mean age 7.9 years, range 3.3 to 17.2 years) underwent bone mineral density (BMD) measurement of the lumbar spine and were evaluated between 2.6 and 5.5 years (mean 3.8) later to determine whether this measurement had predicted risk of fracture over the subsequent period of observation. Other potential risk factors that were evaluated include body weight z score, serum vitamin D levels, previous fracture, and hip spica casting. The baseline measurements showed that BMD falls further below normal with increasing age and was more than one standard deviation below age-matched normal mean in 38 of the 43 patients. Fracture rate did not differ between those with low and those with very low spinal BMD. Similarly, serum vitamin D levels and body weight z scores were not predictive of fracture. However, fracture rate was over fourfold greater following spica casting and more than threefold greater following an initial fracture. Fracture rates in the study group were similar to those reported for age- and sex-matched normal children, though generally the location of the fractures and mechanisms of injury differed.  相似文献   

15.
No reliable identification of quiescent Crohn's disease (CD) patients with a high risk of relapse is available. The aim of this study was to develop a prognostic index to identify those patients. Untreated adult patients with quiescent disease (not induced by surgery) included in three phase III clinical trials were analysed retrospectively with respect to time to relapse. Nineteen factors related to biology, disease history, and topography were investigated. A relapse was defined as either a CD Activity Index (CDAI) > or = 200, a CDAI > or = 150 but over the baseline value by more than 100, or acute complications requiring surgery. The inclusion criteria were fulfilled by 178 patients. The median follow up was 23 months. The Cox model retained the following bad prognostic factors: age < or = 25 years, interval since first symptoms > 5 years, interval since previous relapse < or = 6 months, and colonic involvement (p < 0.001). Bootstrapping confirmed the variable selection. Patients were classified into three groups with an increasing risk of relapse (p < 0.001). The worst risk group was composed of patients presenting at least three of the four bad prognostic factors. These results make possible the design of clinical trials in quiescent CD patients with a high risk of relapse.  相似文献   

16.
Carotid endarterectomy if advised for asymptomatic disease must be associated with a low peri-operative morbidity and mortality and satisfactory long-term results. Over a 12 year period between 1978-1989 181 carotid endarterectomies were performed on 163 patients with asymptomatic carotid artery stenosis. There were 112 males and 51 females with a mean age of 64.9 years. All patients had a high-grade lesion (> 70% stenosis). The combined operative mortality and stroke rate was 2.8%. On long-term follow up six patients suffered a stroke. Only one patient however sustained a stroke in the same territory as the previously operated carotid artery. Four years following surgery 78% of patients were alive. Carotid restenosis or occlusion occurred in 8.3% of the remaining patients, all of whom were asymptomatic. All the immediate postoperative strokes occurred in patients with severe bilateral carotid artery disease. These patients with severe bilateral disease appear to constitute a high risk sub-group for peri-operative stroke. The role of 'normal pressure-hyperperfusion breakthrough' syndrome as the presumed aetiology of two of the postoperative cerebral haemorrhages is discussed.  相似文献   

17.
Three groups of 12 nonalcoholic men at differing degrees of genetic risk for alcoholism were tested with and without alcohol for their cardiovascular response to an aversive stimulus. A high-risk group consisted of sons of alcoholic fathers with extensive transgenerational family histories of alcoholism. A moderate-risk group included sons of alcoholic fathers whose previous generation was essentially negative for other alcoholic diagnoses. The low-risk group consisted of men with negative family histories for the disorder. Heart rate and digital blood volume amplitude were measured in each subject while resting and during a signaled shock procedure. Results show that the high-risk group was more cardiovascularly reactive to the stressor than the moderate-risk group when sober. Alcohol consumption led to a dramatic reduction in the degree of reactivity in the high-risk group, and it led to increased reactivity in the moderate-risk group. The trend for the low-risk group was similar to the moderate-risk group with no significant differences between the two. The methodology and results are discussed in terms of their relevance in the etiology of alcoholism in high-risk men and in terms of the need for generational controls in studying sons of alcoholics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

18.
This study examined occupational risk perception in relation to safety training and injuries. In a printing industry, 350 workers from 6 departments completed a survey. Data analysis showed significant differences in risk perceptions among departments. Differences in risk perception reflected the type of work and the injury incidents in the departments. A structural equation analysis confirmed a model of risk perception on the basis of employees' evaluation of the prevalence and lethalness of hazards as well as the control over hazards they gain from training. The number of injuries sustained was positively related to the perception of risk exposure and negatively related to evaluations about the safety training. The results highlight the importance of training interventions in increasing workers' adoption of safety procedures and prevention of injuries. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Objective: Efficacy trials found that a dissonance-based eating disorder prevention program in which female high school and college students with body image concerns critique the thin ideal reduced eating disorder risk factors, eating disorder symptoms, and future eating disorder onset. The present effectiveness trial tested whether this program produces effects through long-term follow-up when high school clinicians recruit students and deliver the intervention under real-world conditions. Method: Female high school students with body image concerns (N = 306; M age = 15.7 years, SD = 1.1) were randomized to the dissonance intervention or an educational brochure control condition and completed assessments through 3-year follow-up. Results: Dissonance participants showed significantly greater decreases in body dissatisfaction at 2-year follow-up and eating disorder symptoms at 3-year follow-up than controls; effects on other risk factors, risk for eating disorder onset, and other outcomes (e.g., body mass) were marginal or nonsignificant. Conclusions: Although it was encouraging that some key effects persisted over long-term follow-up, effects were on average smaller in this effectiveness trial than previous efficacy trials, which could be due to (a) facilitator selection, training, and supervision; (b) the lower risk status of participants; or (c) the use of a control condition that produces some effects. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

20.
The Special Surveillance Breast Program (SSBP) is a long-term, comprehensive, multidisciplinary program for women determined to be at high risk for the development of breast cancer. Because the women who attend this program are otherwise healthy but concerned about their risk for breast cancer, current and relevant information is required to address their concerns regarding the possibility of developing breast cancer. The purpose of this article is to describe the risk factors that indicate eligibility for the program, the structure of the program, and the results of an assessment that identified the needs of this special population.  相似文献   

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