Aims: Although outcomes after acute myocardiat infarction(AMI) seemed to be superior with primary percutaneous coronary intervention(PPCI) relative to fibrinolysis(FL), the extent to which treatment delay modulates th...Aims: Although outcomes after acute myocardiat infarction(AMI) seemed to be superior with primary percutaneous coronary intervention(PPCI) relative to fibrinolysis(FL), the extent to which treatment delay modulates this treatment effect is unclear. Methods and results: Twenty-five randomized trials(n=7743) testing the efficacy of PPCI vs. FL were identified in journal articles and abstract listings published between 1990 and 2002. Of these, individual patient data from 22 trials(n=6763) were pooled, and multi-level logistic regression assessed the relationship among treatment, treatment delay, and 30-day mortality. Treatment delay was divided into ‘ presentation delay’ [symptom onset to randomization; FL: median 143(IQR: 91-225) min; PPCI: 140(91-220) min] and hospital-sp3ecific ‘ PCI-related delay’ [median time from randomization to PPCI minus median time to FL per hospital; median 55(IQR: 37-74) min]. PPCI was associated with a significant 37% reduction in 30-day mortality [adjusted OR, 0.63; 95% CI(0.42-0.84)]. Although, there was no heterogeneity in the treatment effect by presentation delay(pBreslow-Day=0.88), the absolute mortality reduction by PPCI widened over time(1.3% 0-1 h to 4.2% >6 h after symptom onset). When the PCI-related delay was< 35min, the relative(67 vs. 28% pBreslow-Day=0.004) and absolute(5.4 vs. 2.0% ) mortality reduction was significantly higher than those with longer delays. Conclusion: PPCI was associated with significantly lower 30-day mortality relative to FL, regardless of treatment delay. Although logistic and economic constraints challenge the feasibility of ‘ PPCI-for-all’ , the benefit of timely treatment underscores the importance of a comprehensive, unified approach to delivery of cardiac care in all AMI patients.展开更多
随机对照试验（randomized control test，RCT）在判断干预措施效应的真实程度上，较其它类型的研究设计能提供更强的论证强度，是目前国际上公认的、评价干预措施是否有效的金标准。基于随机对照试验方法的科学性，它不仅适用于西医药...随机对照试验（randomized control test，RCT）在判断干预措施效应的真实程度上，较其它类型的研究设计能提供更强的论证强度，是目前国际上公认的、评价干预措施是否有效的金标准。基于随机对照试验方法的科学性，它不仅适用于西医药干预措施的疗效评价，同样也适用于中医药干预措施的临床疗效评价，因而受到越来越多的中医临床科研工作者的重视。但我们也应认识到，非随机对照试验（non—randomized control trial，non—RCT）对于各级证据均主要源于临床实践的中医药学，以及有着大量非盲法、非随机化临床试验的中医药和中西医结合临床研究，也有着重要的、特殊的意义。展开更多
Objectives: To assess how often new treatments for childhood cancer assessed i n phase III randomised trials are superior or inferior to standard treatments an d whether the pattern of successes and failures in new tr...Objectives: To assess how often new treatments for childhood cancer assessed i n phase III randomised trials are superior or inferior to standard treatments an d whether the pattern of successes and failures in new treatments is consistent with uncertainty being the ethical basis for enrolling patients in such trials. Design: Observational study. Setting: Phase III randomised controlled trials car ried out under the aegis of the Children’s Oncology Group between 1955 and 1997, regardless of whether they were published. Main outcome measures: Overall surv ival, event free survival, and treatment related mortality. Results: 126 trials were included, involving 152 comparisons and 36 567 patients. The odds ratio for overall survival with experimental treatments was 0.96 (99%confidence interval 0.89 to 1.03), indicating mat new treatments are as likely to be inferior as th ey are to be superior to standard treatments. This result was not affected by pu blication bias, methodological quality, treatment type, disease, or comparator. Conclusions: New treatments in childhood cancer tested in randomised controlled trials are, on average, as likely to be inferior as they are to be superior to s tandard treatments, confirming that the uncertainty principle has been operating .展开更多
文摘Aims: Although outcomes after acute myocardiat infarction(AMI) seemed to be superior with primary percutaneous coronary intervention(PPCI) relative to fibrinolysis(FL), the extent to which treatment delay modulates this treatment effect is unclear. Methods and results: Twenty-five randomized trials(n=7743) testing the efficacy of PPCI vs. FL were identified in journal articles and abstract listings published between 1990 and 2002. Of these, individual patient data from 22 trials(n=6763) were pooled, and multi-level logistic regression assessed the relationship among treatment, treatment delay, and 30-day mortality. Treatment delay was divided into ‘ presentation delay’ [symptom onset to randomization; FL: median 143(IQR: 91-225) min; PPCI: 140(91-220) min] and hospital-sp3ecific ‘ PCI-related delay’ [median time from randomization to PPCI minus median time to FL per hospital; median 55(IQR: 37-74) min]. PPCI was associated with a significant 37% reduction in 30-day mortality [adjusted OR, 0.63; 95% CI(0.42-0.84)]. Although, there was no heterogeneity in the treatment effect by presentation delay(pBreslow-Day=0.88), the absolute mortality reduction by PPCI widened over time(1.3% 0-1 h to 4.2% >6 h after symptom onset). When the PCI-related delay was< 35min, the relative(67 vs. 28% pBreslow-Day=0.004) and absolute(5.4 vs. 2.0% ) mortality reduction was significantly higher than those with longer delays. Conclusion: PPCI was associated with significantly lower 30-day mortality relative to FL, regardless of treatment delay. Although logistic and economic constraints challenge the feasibility of ‘ PPCI-for-all’ , the benefit of timely treatment underscores the importance of a comprehensive, unified approach to delivery of cardiac care in all AMI patients.
文摘随机对照试验（randomized control test，RCT）在判断干预措施效应的真实程度上，较其它类型的研究设计能提供更强的论证强度，是目前国际上公认的、评价干预措施是否有效的金标准。基于随机对照试验方法的科学性，它不仅适用于西医药干预措施的疗效评价，同样也适用于中医药干预措施的临床疗效评价，因而受到越来越多的中医临床科研工作者的重视。但我们也应认识到，非随机对照试验（non—randomized control trial，non—RCT）对于各级证据均主要源于临床实践的中医药学，以及有着大量非盲法、非随机化临床试验的中医药和中西医结合临床研究，也有着重要的、特殊的意义。
文摘Objectives: To assess how often new treatments for childhood cancer assessed i n phase III randomised trials are superior or inferior to standard treatments an d whether the pattern of successes and failures in new treatments is consistent with uncertainty being the ethical basis for enrolling patients in such trials. Design: Observational study. Setting: Phase III randomised controlled trials car ried out under the aegis of the Children’s Oncology Group between 1955 and 1997, regardless of whether they were published. Main outcome measures: Overall surv ival, event free survival, and treatment related mortality. Results: 126 trials were included, involving 152 comparisons and 36 567 patients. The odds ratio for overall survival with experimental treatments was 0.96 (99%confidence interval 0.89 to 1.03), indicating mat new treatments are as likely to be inferior as th ey are to be superior to standard treatments. This result was not affected by pu blication bias, methodological quality, treatment type, disease, or comparator. Conclusions: New treatments in childhood cancer tested in randomised controlled trials are, on average, as likely to be inferior as they are to be superior to s tandard treatments, confirming that the uncertainty principle has been operating .
