Lilford R J, Thornton J G, Braunholtz D
West Midlands Health Authority, Arthur Thomson House, Birmingham.
BMJ. 1995 Dec 16;311(7020):1621-5. doi: 10.1136/bmj.311.7020.1621.
Currently, clinical trials tend to be individually funded and applicants must include a power calculation in their grant request. However, conventional levels of statistical precision are unlikely to be obtainable prospectively if the trial is required to evaluate treatment of a rare disease. This means that clinicians treating such diseases remain in ignorance and must form their judgments solely on the basis of (potentially biased) observational studies experience, and anecdote. Since some unbiased evidence is clearly better than none, this state of affairs should not continue. However, conventional (frequentist) confidence limits are unlikely to exclude a null result, even when treatments differ substantially. Bayesian methods utilise all available data to calculate probabilities that may be extrapolated directly to clinical practice. Funding bodies should therefore fund a repertoire of small trials, which need have no predetermined end, alongside standard larger studies.
目前，临床试验往往是由个别机构资助的，申请者在其资助申请中必须包含功效计算。然而，如果试验需要评估罕见病的治疗方法，那么前瞻性地获得传统水平的统计精度是不太可能的。这意味着治疗此类疾病的临床医生仍然一无所知，并且必须完全基于（可能有偏差的）观察性研究经验和轶事来形成他们的判断。由于一些无偏证据显然总比没有好，这种情况不应再持续下去。然而，传统的（频率学派）置信区间不太可能排除无效结果，即使治疗方法有很大差异。贝叶斯方法利用所有可用数据来计算可以直接外推到临床实践中的概率。因此，资助机构应该资助一系列小型试验，这些试验不需要有预定的终点，同时也要资助标准的大型研究。
