Evidence-based medicine in rapidly changing technologies

Evidence-based medicine (EBM) is not a randomised controlled trial (RCT), but EBM seeks to apply evidence gained from scientific methods - which could be RCT - to daily medical practice. Any surgical treatment reflects a certain development technically as well as skills based. The procedure may be modified and refined and the device may be developed and inherent technical weaknesses may need to be corrected. Therefore the best time to conduct a trial may be discussed. The appropriate time to initiate a RCT is when all the participating surgeons or therapists have gone through their learning curve. Special considerations should be given in rapidly developing fields. If started too early the resulting comparison will likely turn out to be irrelevant because the new technology is not fully developed, not mastered or the device may have undergone major modifications rendering the results obsolete. On the other hand, if started too late there is a chance that data may be lost because the technology has already been introduced into the daily clinics and physicians may be unwilling to recruit patients. Or the opposite, that the technique may have been rejected without a proper trial. In this situation it has been suggested to perform a so called tracker trial. In such trials protocols are more flexible without prefixed sample size and will require repeated interim analyses. Often, it will be relevant to supplement the clinical trials with data from large clinical databases - in particular when long term results are needed.