"Research has shown that people find approximately 95% of mistakes when checking the work of others."
This quote is from: ISMP Canada Safety Bulletin "Lowering the Risk of Medication Errors: Independent Double Checks". Volume 5 Issue 1 January 2005.
The ISMP Bulletin refers the reader to the research paper: Campbell, GM, Facchinetti, NJ. Using process control charts to monitor dispensing and checking errors. Am J Health-System Pharm 1998;55(9):946-952
Partners in Patient Safety