500
The benefits, risks, burdens and effectiveness of a new intervention must be tested against those of the best proven intervention(s), except in the following circumstances:
1-Where no proven intervention exists, the use of placebo, or no intervention, is acceptable
2-Where for compelling and scientifically sound methodological reasons the use of any intervention less effective than the best proven one, the use of placebo, or no intervention is necessary to determine the efficacy or safety of an intervention
3-Extreme care must be taken to avoid abuse of this option