走出循证医学的误区——关于证据的反思

循证医学在临床实践中起着越来越重要的作用,证据的可靠性是循证医学赖以生存的基石。循证医学遵循的证据来自随机对照试验,这些证据并非完美。临床医师在采纳这些证据时须注意以下几个方面的问题证据的适用人群,干预措施是否存在均一性,对照是否存在片面性,试验的研究终点是否与临床脱节,证据的时效性,以及随机试验提供的证据不足等。只有结合医生的专业技能和临床经验,考虑病人的价值和愿望,对证据进行正确评估和采纳,才能使证据发挥最大的效能,促进循证医学的发展。     

为病患代购管制药品的情与法冲突及化解路径

为病患代购管制药品的案件在刑法上往往面临情与法的冲突。司法机关不愿意、却不得不定罪,只能在量刑时突破法律框架,尽量从轻。在刑法的实质解释下,为病患代购管制药品不成立贩卖毒品罪、非法经营罪或妨害药品管理罪,应处无罪。在刑事个案中,“情理”虽不能直接介入,但对刑法体系的适用具有批判功能。当“法理”分析的结论与公众的法直觉相违背时,应当检讨“法理”之适用过程是否出错,使刑事个案体现刑法正义,实现情与法的统一。

     

侵入式脑机接口技术临床试验的伦理考量

侵入式脑机接口在临床上有巨大应用价值,尤其在神经及精神疾病方面。然而,其临床试验提出不同于传统的特殊伦理挑战,在内涵和优先次序上与其他新兴生物技术的看似相同实则不同。研究参与者多为病情无现有可行治疗措施或晚期患者,试验目的在获取知识的同时解决其健康问题;试验在遵循风险最小化原则基础上,还需使风险与疾病严重程度相称;人脑有创试验可能影响人的自主性,需采用动态知情同意模式;此外,试验暴露更多隐私泄露风险。基于上述,研究者需对侵入式脑机接口临床试验保持高度关注。     

Principles and Problems in the Assessment of Quality of Life in Health Care

A remarkable surge in efforts to assess the quality of life of patients has occurred in recent years in medical research. Philosophical discussions of these developments have focused, on the one hand, on epistemological reservations about the plausibility of measuring quality of life and, on the other hand, on moral and ethical qualms about the meaning of life conveyed in such assessments. Whilst providing an important note of caution, such critiques fail to recognise two basic principles of quality of life in medical research. Firstly it is intended to provide understanding about groups and categories of patients rather than individuals. Secondly the purpose of such research is to produce generalisations about the relative costs and benefits of specific health care interventions rather than absolute judgements regarding the quality of life of patients per se. Selecting a good quality of life measure for a clinical trial requires balancing criteria such as validity with practical feasibility. Such measures will play an increasingly central role in providing research evidence to improve health care.     

Mindfulness-based stress reduction for patients with anxiety disorders: evaluation in a randomized controlled trial

The aim of this study was to investigate the effect of mindfulness-based stress reduction (MBSR) for patients with heterogeneous anxiety disorders. Seventy-six self-referred patients were randomized to MBSR or a waiting-list control condition. Eight participants did not complete the eight-week MBSR intervention. Treatment completers improved significantly on all outcome measures compared to controls. The completer sample showed medium to large effect sizes on measures of anxiety (Cohen’s d = 0.55–0.97), and a large effect size for symptoms of depression (Cohen’s d = 0.97). Intention-to-treat analyses yielded effect sizes in the small to moderate range (Cohen’s d = 0.32–0.76). Gains were maintained at six months follow-up. The percentage of participants reaching recovered status was highest for symptom measures of depression and anxiety, and lower for worry and trait anxiety. Mediation analyses indicated that mindfulness fully mediated changes in acute anxiety symptoms, and partially mediated changes in worry and trait anxiety. However, the present study did not find evidence of temporal precedence for the proposed mediator. In the absence of true mediation and an active control condition, it cannot be ruled out that results are due to non-specific aspects of treatment. Despite these and other limitations, we conclude that MBSR is an effective treatment for anxiety disorders and related symptomatology.     

Transdiagnostic internet treatment for anxiety and depression: a randomised controlled trial

Disorder-specific cognitive behavioural therapy programs delivered over the internet (iCBT) with clinician guidance are effective at treating specific anxiety disorders and depression. The present study examined the efficacy of a transdiagnostic iCBT protocol to treat three anxiety disorders and/or depression within the same program (the Wellbeing Program). Seventy-seven individuals with a principal diagnosis of major depression, generalised anxiety disorder, panic disorder, and/or social phobia were randomly assigned to a Treatment or Waitlist Control group. Treatment consisted of CBT-based online educational lessons and homework assignments, weekly email or telephone contact from a clinical psychologist, access to a moderated online discussion forum, and automated emails. Eighty one percent of Treatment group participants completed all 8 lessons within the 10 week program. Post-treatment data were collected from 34/37 Treatment group and 35/37 Control group participants, and 3-month follow-up data were collected from 32/37 Treatment group participants. Relative to Controls, Treatment group participants reported significantly reduced symptoms of anxiety and depression as measured by the Depression Anxiety and Stress Scales-21 item, Patient Health Questionnaire-9 item, and Generalised Anxiety Disorder-7 item scales, with corresponding between-groups effect sizes (Cohen’s d) at post treatment of.56,.58, and.52, respectively. The clinician spent a mean time of 84.76 min (SD = 50.37) per person over the program. Participants rated the procedure as highly acceptable, and gains were sustained at follow-up. These results provide preliminary support for the efficacy of transdiagnostic iCBT in the treatment of anxiety and depressive disorders.     

Placebos and the UK medical research council — and the consumer perspective

The UK Medical Research Council, in order to further its mission of maintaining and improving human health, supports a substantial number of clinical trials on a wide variety of medical questions; some of these trials involve the use of placebos as controls or to maintain blinding. Before providing support, proposed trials are carefully reviewed to assess scientific quality, and to determine whether a placebo is required and is ethical — in addition to ethics review by independent Research Ethics Committees. Some questions such as the choice of placebos in trials in developing countries, in surgical trials and those involving alternative medicine require consideration of additional, specific issues. Involvement of consumers in MRC work has been increasing and includes the establishment of a Consumer Liaison Group; members of this group comment on patient information leaflets for clinical trials, helping to improve patient understanding of trials and ensuring topics like placebo use are explained clearly. Views differ on the value of placebos in clinical care and on their mechanism of action; continuing research is helping to clarify the issues. An earlier version of this paper was presented at an international conference, “Placebo: Its Action and Place in Health Research Today,” held in Warsaw, Poland on 12–13 April, 2003.     

Electrophysiological response during source memory decisions in older and younger adults

We recorded event-related potentials (ERPs) as individuals made source monitoring decisions in a paradigm in which the influence of item familiarity and goal relevance could be separately evaluated. Younger and older adults read a list of words and subsequently distinguished these words from foils in a running recognition test in which some foils were repeated after a lag of 6 items, creating familiar lures. Behaviorally, older and younger adults performed equally well in the recognition of study words and the rejection of singly presented foils. However, older adults were more likely to respond to the familiar lures as though they had come from the study list, thus producing the expected group difference in source-monitoring error. For younger adults the ERPs elicited by the targeted study words were maximal at posterior sites and significantly greater than those elicited by either familiar lures or foils. Older adults generated far less differentiated ERP waveforms but with a markedly greater amplitude at frontal sites. We interpret this frontal maximum in the context of poorer source monitoring as suggesting that older adults are more dependent on controlled processes to make discriminations that seem to occur much earlier and more automatically for younger adults.     

Using Technology to Deliver Immediate Corrective Feedback to Preservice Teachers

Teacher preparation programs are under scrutiny for their role in the troubled American educational system. If American education is to improve, teacher educators must identify and encourage teachers to use effective teaching practices. A promising technique for increasing use of teaching practices is providing feedback to teachers on newly acquired behaviors. The focus of this study was to examine the effects of immediate corrective feedback on one specific teaching behavior, use of three-term contingencies, to preservice teachers. A multiple baseline design across participants was used to evaluate the effects of immediate corrective feedback, delivered via a wireless FM listening system. Immediate corrective feedback (as compared with delayed feedback) was shown to be an effective way to increase preservice teacher completion of three-term contingency trials by all participants. These findings and other considerations for additional research using feedback are addressed.