如何评价RCT的外部.pptVIP

如何评价RCT的外部真实性 研究的真实性 定义：充分考虑了各种影响结论或推断的因素后，将研究的结果外推至样本以外的人群时的真实程度。 内部真实性 (Internal Validity) 外部真实性 (External Validity) 内部真实性 一项能正确反映研究人群及目标人群真实情况的研究结果的外延性 反映研究结果受系统误差的影响程度 强调研究结果是否无偏的反映了研究因素与疾病之间的关系 外部真实性 一项具有内部真实性的结果推广至目标人群以外的人群仍然有效 研究结论可外推至不同时间，不同地区的不同人群 两者关系 无内部真实性的结果，不可能有外部真实性 有内部真实性的结果，不一定具有外部真实性 Validity of routinely collected data “Non-randomised treatment comparisons based on routinely collected data are often suggested to be more externally valid than RCTs because they include all patients, are done in the real world, and include the effects of the doctor-patient relationship and patient preference.” Validity of routinely collected data 虽然一些RLP的研究结果通过调整(Adjustment)后与RCT的结论具有相似性 但是偏倚仍将很明显，并且无法校正。 “Although with appropriate adjustment for differences in case-mix the results are sometimes similar to those from RCTs, it is impossible to be certain that bias will be evident or amenable to correction. ” Conclusion “Routinely collected data are useful where RCTs are impractical, such as in evaluating rare adverse events, but are an adjunct rather than an alternative.” RCT vs. RLP for BPH Treatment Advantages of RCT Well characterized Good clinical practice (GCP) guideline Source data verification Resulting date more reliable Randomize, control group, double-blind Run in phase: reduce a possible placebo effect in the active treatment phase RLP A tradition of uncontrolled, a large-scale, open label, observational study UK: “Green Card” Scheme German: Post-marketing observational study These types of studies do not interfere with physician decisions Disadvantages of RLP Lack inclusion and exclusion criteria No control group, blinding, run-in phase No source data validation Poorly differentiate between ‘spontaneous’ and treatment-induced efficacy and tolerability Have a low internal validity. Treatment efficacy in RCT vs.RLP Greater treatment-induced improvements were seen in RLP studies than in RCTs Symptom scores Qmax Improvement of