The re-evaluation of the effectiveness of new drugs is of great importance when they are in post-market for there exist some limitations in clinical trials before these drugs are put on the market. The large sample multi-centre randomized controlled trial is the best method of re-evaluation of the effectiveness of new drugs. It could appropriately evaluate not only the large-term efficacy and safety of drugs, but the treatment effect on the survival state and its complications as well. This method will also lead to a great social amp; economic benefit.