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1.
关于循证医学、精准医学和大数据研究的几点看法   总被引:5,自引:2,他引:3       下载免费PDF全文
循证医学仍是当今最好的医学实践模式。需要注意的是,证据本身不等于决策,决策还必须考虑现有资源和人们的价值取向。证据显示,绝大多数患者不会因使用降血压、降血脂、降血糖、抗癌药而预防重要并发症或死亡,说明现代医学的很多诊断和治疗都不精准,找到那几个为数不多的对治疗有反应的患者就成了现代医学的梦。精准医学应运而生,但它并不是新概念,也不等于孤注一掷的基因测序。精准医学依赖的大队列多因素研究由来已久,也不是新方法。医学一直在寻求精准,而且在人类认知的各个层面都有所建树,如疫苗和抗体、血型与输血、影像对病灶的定位以及白内障晶体替换手术。基因不是达到精准的唯一途径,只是提供了新的可能性。但是多数基因和疾病关联强度很低,说明基因精准指导防治的价值可能不大,利用大数据和其他预测因素是精准医学的必经之路。在使用大数据问题上,强调拥有总体、大样本、关联关系而淡化因果关系,是严重的误导。科学从来不会待考察了总体后才进行推论;研究需要的样本量恰恰与效果大小成反比;否定因果关系就是对流行病学科学原理和方法的否定,放弃了对真实性的保障,最终会导致防治的无效。因此,在确认疗效上,基于大数据的现实世界观察性结果不能取代随机对照试验的实验性证据。本文谨希望以怀疑和批评的方式,激发出精准医学和大数据蕴藏的真正潜力。  相似文献   

2.
传统上,流行病学多以干预划分观察和实验,干预研究等于实验研究,还认为干预研究的科学性高于观察性研究。在一般科学实验里,干预指人为施加的改变自然状况的措施。干预并不一定是有益的,也并不一定是研究者当下施加的,研究者、受试者或第三者目前或过去施加的措施都可以形成"有效的"干预。例如,由研究者、受试者和第三者通过某种方法致使视神经损伤,都可以形成有效改变视神经正常功能的干预,研究者可以由此观察到视神经和视力的关系。以此推论,由受试者自己过去施加的不良干预(如吸烟)也属于干预,那么研究吸烟和肺癌的观察性队列研究就等同于实验研究了。由此看来,干预本身并不足以有效地区分观察和实验。如果认为实验的科学性高于观察,那么在干预的基础上,只能从科学性上(即设计特征)区分观察和实验。在评估医学干预效果的临床试验中,随机分组是在传统认为的观察研究基础上引入的最重要的偏倚控制措施,应该是区分观察和实验的核心属性。如果一定要把人群研究分成观察和实验,随机对照试验才是真正的实验研究,非随机分组形成的干预研究属于试验,但不是实验。基于大数据的现实世界研究,如果没有随机分组,不能构成实验,也不能成为对干预效果的最终检验。大数据现实世界研究不能取代随机对照试验,这是本文希望传达的最重要的信息。  相似文献   

3.
起源及发展循证设计的概念来源于循证医学。1972年,苏格兰流行病学家Archie Cochrane出版《医疗服务疗效与效益随想》(Effectiveness and Efficiency:Random Reflection of Health Services)一书,大力提倡严谨的研究方法(如随机对照试验)及以可靠的科研成果为依据的医学临床实践。在Cochrane的理论基础上,McMaster大学的学者David Sackett和Gordon Guyatt在1990年提出了  相似文献   

4.
临床真实世界研究中的实验性研究设计   总被引:2,自引:2,他引:0       下载免费PDF全文
真实世界研究作为解释性随机对照试验在医疗实践中评价干预措施效果的进一步验证和补充已成为医疗卫生领域关注的焦点。但是也存在错误将真实世界研究等同于观察性研究,认为真实世界研究不能实施人为干预,更不能采取随机化。实际上,真实世界研究的基本设计既可以是观察性的,也可以是实验性的。其中真实世界研究的实验性研究设计主要是指实用性随机对照试验和基于注册登记研究的随机对照试验,也可采用非随机对照、自适应设计等其他研究设计方案。  相似文献   

5.
当两种不同的药物需要通过临床试验判断它们之间的疗效是否存在差别时,在统计学上有三种类型的设计方案.第一种是固定样本设计方案.这种传统的随机对照临床试验设计要求试验开始前确定样本量,并且只有当所有的受试者均完成入组之后才能进行数据的统计分析.  相似文献   

6.
研究的样本代表性一直是流行病学领域内具有争议性的话题之一。本文首先对流行病学样本代表性进行定义,同时对研究人群、源人群、目标人群、内部真实性、外部真实性等相关流行病学基本概念进行阐述。在此基础上,本文深入分析了横断面研究、队列研究、病例对照研究、干预性研究四种主要流行病学研究设计中样本代表性的价值和实际可行性。总而言之,除针对人群疾病或健康现状的横断面研究外,多数涉及病因或干预效果推断的流行病学研究不应过度强调样本代表性。  相似文献   

7.
目的:评价认知行为干预对心力衰竭患者负性情绪的影响。方法:采用Meta分析的办法,检索多个中、英文数据库,搜集相关临床随机对照试验,进行文献质量评价后,采用Rev Man5.2软件进行数据分析。结果:共纳入4篇随机对照试验(RCT)研究、结果显示:认知行为干预对心力衰竭负性情绪抑郁(SAS)和焦虑(SDS)有同质性。结论:认知行为干预对心力衰竭负性情绪抑郁(SAS)和焦虑(SDS)有效果,由于样本量有限,需要多中心、大样本继续证实这一研究的可靠性。  相似文献   

8.
真实世界研究、随机对照试验及单病例随机对照试验在设计及具体的实施环节上存在明显不同.随机对照试验属于新治疗措施实施前的研究,真实世界研究属于新治疗措施实施后的研究.两者不是对同一个问题的平行论证,而是承启关系.精心设计的随机对照试验是临床上任何干预措施效果评价的基础,其结果需要真实世界研究的进一步验证及拓展补充,综合考虑二者才是最佳的选择.单病例随机对照试验更易在短时间内获得一些特殊病例的信息,是随机对照试验结果的良好补充,也是一定条件下最经济的真实世界研究.临床工作及其研究是十分复杂的过程.不同个体虽患同种疾病,但临床表现互有差异,且临床反应的变化也不尽相同.因此,无法获得同一干预措施下不同个体的相同治疗效果;加之有的治疗措施缺乏真实性和实用价值,从而使得疗效评价成为一个难题.近些年来,普遍采用试验性的研究结果作为证据指导临床实践活动,其中以随机对照试验(RCT)最为受到重视,但由于RCT属于药物面市前研究,对研究对象的选择、治疗措施的应用等均有严格的限定.  相似文献   

9.
真实世界研究、随机对照试验及单病例随机对照试验在设计及具体的实施环节上存在明显不同.随机对照试验属于新治疗措施实施前的研究,真实世界研究属于新治疗措施实施后的研究.两者不是对同一个问题的平行论证,而是承启关系.精心设计的随机对照试验是临床上任何干预措施效果评价的基础,其结果需要真实世界研究的进一步验证及拓展补充,综合考虑二者才是最佳的选择.单病例随机对照试验更易在短时间内获得一些特殊病例的信息,是随机对照试验结果的良好补充,也是一定条件下最经济的真实世界研究.临床工作及其研究是十分复杂的过程.不同个体虽患同种疾病,但临床表现互有差异,且临床反应的变化也不尽相同.因此,无法获得同一干预措施下不同个体的相同治疗效果;加之有的治疗措施缺乏真实性和实用价值,从而使得疗效评价成为一个难题.近些年来,普遍采用试验性的研究结果作为证据指导临床实践活动,其中以随机对照试验(RCT)最为受到重视,但由于RCT属于药物面市前研究,对研究对象的选择、治疗措施的应用等均有严格的限定.  相似文献   

10.
本文对美国卫生保健研究和质量机构(Agency for Healthcare Research and Quality,AHRQ)推荐的干预性研究偏倚风险评价工具的主要内容进行详细解读,并展示如何使用Revman软件制作偏倚风险评价图。AHRQ偏倚风险评价工具是一种综合评价工具,可用来评价常见的研究设计类型(随机对照试验研究、有对照的临床试验研究、队列研究、病例对照研究、病例系列研究、横断面研究)的偏倚风险。该工具从选择偏倚、实施偏倚、随访偏倚、测量偏倚、报告偏倚5个领域来评价研究的偏倚风险,每个领域含有不同的条目,每个条目适用于评价1种或几种研究设计类型。值得注意的是应根据不同的研究设计类型选择相应的条目进行评价而不是直接使用所有条目进行偏倚风险评价。当1个干预性研究的系统综述纳入了多种研究设计类型时,只需要用AHRQ工具就可以评价纳入研究存在的常见偏倚风险,省去了使用不同偏倚风险工具进行偏倚风险评价的繁琐过程。该工具条目相对简单易懂,评价流程不复杂。AHRQ推荐使用高、中、低的偏倚风险分类方法评价纳入研究总体偏倚风险的高低,但是,其对如何判定总体偏倚风险的高低没有给出推荐意见,如何具体判定干预性研究偏倚风险等级的界值,仍有待更多这方面的研究结果。  相似文献   

11.
BackgroundCognitive behavioral therapies for posttraumatic stress disorder (PTSD) are evidence-based and effective for many. However, the reach and impact of these interventions are limited. Physical interventions hold potential to bridge a gap in the unmet treatment of trauma and stressor-related disorders.MethodThis systematic review examined 84 studies from four decades of research on physical interventions for trauma and stressor-related disorders to: 1) describe the state of the field and 2) summarize the best available evidence. Reviewed studies were described in terms of measured sample characteristics and assessed outcomes. Treatment effect patterns were analyzed by intervention content and study design.ResultsThe majority of studies (65.9%) reported statistically significant reductions in posttraumatic stress symptoms; 40.9% used a randomized controlled trial (RCT) design. Among RCTs, one performed rigorous, statistically powered analyses in an intention-to-treat sample.LimitationsHigh variability in reporting strategies among reviewed studies precludes analysis of variables such as intervention length, frequency, and dropout.ConclusionPreliminary evidence for the efficacy of physical interventions for trauma and stressor-related disorders is promising. Larger scale RCTs powered and designed to identify mediators and moderators of these interventions are warranted.  相似文献   

12.
BackgroundMeta-analyses of randomized controlled trials (RCTs) provide the highest level of evidence regarding the effectiveness of interventions. Less is known about how they are used to inform the design and reporting of RCTs.MethodsA sample of RCTs published in leading medical journals in 2007 was assessed to establish whether authors considered previous trials in the design of their trial. An approach to calculate the sample size required for a significant pooled effect in an updated meta-analysis was applied to a subsample of the RCTs to illustrate the ways in which the results of an existing meta-analysis can be incorporated into the planning and reporting of new RCTs.ResultsSix of the 27 trials assessed (22%) reported the use of previous trial(s) for sample size calculations. Meta-analyses relating the results of the trial to previous research were cited in 37% (10 out of 27) of the report discussion sections. Previous evidence is formally incorporated into retrospective sample size calculations for three of the trials.Discussion/ConclusionConsulting previous research before embarking on a new trial and basing decisions about future research on the impact on an updated meta-analysis will make the reporting of research more coherent and the design of new RCTs more efficient.  相似文献   

13.
Some epidemiological evidence suggests that diets high in omega 3 fatty acids (n-3 FAs) may be beneficial for skeletal health. The aim of this systematic review was to determine if randomized controlled trials (RCTs) support a positive effect of n-3 FAs on osteoporosis. A systematic search was performed in PubMed and EMBASE databases. We included RCTs with skeletal outcomes conducted in adults or children (> = 1 year old) using n-3 FA fortified foods, diets or supplements alone or in combination with other vitamins/minerals, versus placebo. Primary outcomes were incident fracture at any site and bone mineral density (BMD) in g/cm2. Secondary outcomes included bone formation or resorption markers and bone turnover regulators. A total of 10 RCTs met inclusion criteria. Effect sizes with 95 % confidence intervals were estimated to compare studies across various treatments and outcome measures. No pooled analysis was completed due to heterogeneity of studies and small sample sizes. No RCTs included fracture as an outcome. Four studies reported significant favorable effects of n-3 FA on BMD or bone turnover markers. Of these, three delivered n-3 FA in combination with high calcium foods or supplements. Five studies reported no differences in outcomes between n-3 FA intervention and control groups; one study included insufficient data for effect size estimation. Strong conclusions regarding n-3 FAs and bone disease are limited due to the small number and modest sample sizes of RCTs, however, it appears that any potential benefit of n-3 FA on skeletal health may be enhanced by concurrent administration of calcium.  相似文献   

14.

Background

Detection of modest but worthwhile treatment effects in randomized controlled trials (RCTs) demands trials of large sample size. Approaches to decreasing required size of RCTs while maintaining power are needed.

Objective

The epidemiological concept of population attributable fraction (AFp) was applied to the population selected for an RCT to assess its role in determining the size of treatment effect and the required sample size. The additional effect of efficacy of treatment specifically among participants at risk for attributable target events (relative risk reductionat risk [RRRat risk]) was also examined.

Results

A model is described which accounts for size of treatment effect in an RCT based on AFp and RRRat risk: RRRtrial = (AFp) (RRRat risk). The increase in RRRtrial resulting from raising AFp exceeds that possible under the traditional high risk/high response approach to trial design and allows a reduction in required trial sample size. AFp can be estimated from studies of causation that determine both risk and attributable risk (AR) associated with specific risk factors.

Conclusion

Larger treatment effects within RCTs are enabled by choosing a target outcome having a specific cause and selecting participants at specific risk for that outcome. Using information about phenotypic and genetic predictors of AR may increase our capacity to select trial populations having high AFp.  相似文献   

15.
Structural interventions addressing macro-social determinants of risk have been suggested as potentially important adjuncts to biomedical and behavioural interventions for the prevention of HIV and other diseases. A few interventions of this type have been evaluated using randomised controlled trials (RCTs), the most rigorous design to evaluate the effects of biomedical and behavioural interventions. The appropriateness of applying RCTs to structural interventions is however debated. This paper considers whether issues of ethics, feasibility and utility preclude the use of RCTs in evaluations of structural interventions for HIV prevention. We conclude there is nothing particular to this category of interventions prohibiting use of RCTs. However, we suggest that RCTs may prove unacceptable, unfeasible or not useful in certain circumstances, such as where an intervention brings important benefits other than HIV prevention (such as increased income); where leaders of clusters do not allow decisions about macro-social policies to be determined randomly; where the unit of social organization addressed by an intervention is so large that recruitment of adequate numbers of clusters is impossible; and where the period required to trial interventions extends beyond practical decision-making time-scales. In such cases, alternative evaluative designs must be assessed for their ability to provide evidence of intervention effectiveness.  相似文献   

16.
Background: The purpose of this methodological review is to quantify and qualify critical care nutrition randomized controlled trials (RCTs) that inform our practice, to evaluate their strengths and limitations, and to recommend strategies for improving the design of future trials in this area. Methods: The literature was systematically reviewed to find all RCTs published between 1980 and December 2008 that evaluated nutrition interventions in critical care. Data were abstracted on the nature and quality of included RCTs. Results: A total of 207 RCTs met the inclusion criteria. Of these, 170 (82.1%) were single‐center, and 37 (17.9%) were multicenter. The largest number of trials evaluated intensive insulin therapy (n = 25), arginine‐supplemented diets (n = 22), and supplemental parenteral glutamine (n = 17). The first RCTs were published in 1983 (n = 2), and the mean sample size was 39.0. In 2008, there were 26 RCTs, each enrolling an average of 237.1 patients. Excluding 2 cluster RCTs, 62 of 205 (30.2%) trials had concealed randomization, 125 of 205 (61.0%) reported on intention‐to‐treat analyses, and 69 of 205 (33.7%) had a double‐blinded intervention; 18 of 205 (8.8%) studies reported on all 3 design characteristics. Currently, 60 critical care nutrition RCTs (18 multicenter trials) are registered on clinical trials registries. Conclusions: The future of clinical critical care nutrition research is promising, with more trials of increasing sample size being conducted. Robust trial methodology, transparent reporting, and the development of research networks will help to further advance this important field.  相似文献   

17.
In evaluating randomized control trials (RCTs), statistical power analyses are necessary to choose a sample size which strikes the balance between an insufficient and an excessive design, with the latter leading to misspent resources. With the growing popularity of using longitudinal data to evaluate RCTs, statistical power calculations have become more complex. Specifically, with repeated measures, the number and frequency of measurements per person additionally influence statistical power by determining the precision with which intra-individual change can be measured as well as the reliability with which inter-individual differences in change can be assessed. The application of growth mixture models has shown that the impact of universal interventions is often concentrated among a small group of individuals at the highest level of risk. General sample size calculations were consequently not sufficient to determine whether statistical power is adequate to detect the desired effect. Currently, little guidance exists to recommend a sufficient assessment design to evaluating intervention impact. To this end, Monte Carlo simulations are conducted to assess the statistical power and precision when manipulating study duration and assessment frequency. Estimates were extracted from a published evaluation of the proximal of the Good Behavior Game (GBG) on the developmental course of aggressive behavior. Results indicated that the number of time points and the frequency of assessments influence statistical power and precision. Recommendations for the assessment design of longitudinal studies are discussed.  相似文献   

18.
To review research evidence on the effectiveness of monetary incentives in modifying dietary behavior, we conducted a systematic review of randomized, controlled trials (RCTs) identified from electronic bibliographic databases and reference lists of retrieved relevant articles. Studies eligible for inclusion met the following criteria: RCT comparing a form of monetary incentive with a comparative intervention or control; incentives were a central component of the study intervention and their effect was able to be disaggregated from other intervention components; study participants were community-based; and outcome variables included anthropometric or dietary assessment measures. Data were extracted on study populations, setting, interventions, outcome variables, trial duration, and follow-up. Appraisal of trial methodological quality was undertaken based on comparability of baseline characteristics, randomization method, allocation concealment, blinding, follow-up, and use of intention-to-treat analysis. Four RCTs were identified as meeting the inclusion criteria. All four trials demonstrated a positive effect of monetary incentives on food purchases, food consumption, or weight loss. However, the trials had some methodological limitations including small sample sizes and short durations. In addition, no studies to date have assessed effects according to socioeconomic or ethnic group or measured the cost-effectiveness of such schemes. Monetary incentives are a promising strategy to modify dietary behavior, but more research is needed to address the gaps in evidence. In particular, larger, long-term RCTs are needed with population groups at high risk of nutrition-related diseases.  相似文献   

19.
行人分心是交通伤害的重要危险因素之一。本文就国内外行人分心流行特征、影响因素、安全影响,以及现有干预措施进行综述。结果显示:①行人分心发生率高,严重威胁行人安全,但当前大多数行人分心流行特征研究集中于手机使用,采用不同研究方法、来自不同国家的行人分心发生率存在较大差异;②人口学特征、社会心理和环境是行人分心发生的主要影响因素;③行人分心通过对生理认知、运动控制、过街效率和过街行为造成不同程度的影响,威胁行人安全;④工程干预和教育是最常见的行人分心干预措施,但大多数措施的效果未被严格评估。建议未来从多学科角度开展深入的流行病学研究,精准设计干预措施,严格评估干预措施的效果,为减少行人分心、提高行人交通安全提供科学依据。  相似文献   

20.
行人分心流行特征与干预研究进展   总被引:2,自引:0,他引:2       下载免费PDF全文
行人分心是交通伤害的重要危险因素之一。本文就国内外行人分心流行特征、影响因素、安全影响,以及现有干预措施进行综述。结果显示:①行人分心发生率高,严重威胁行人安全,但当前大多数行人分心流行特征研究集中于手机使用,采用不同研究方法、来自不同国家的行人分心发生率存在较大差异;②人口学特征、社会心理和环境是行人分心发生的主要影响因素;③行人分心通过对生理认知、运动控制、过街效率和过街行为造成不同程度的影响,威胁行人安全;④工程干预和教育是最常见的行人分心干预措施,但大多数措施的效果未被严格评估。建议未来从多学科角度开展深入的流行病学研究,精准设计干预措施,严格评估干预措施的效果,为减少行人分心、提高行人交通安全提供科学依据。  相似文献   

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