Table 1

Rating scales used to compute the risk priority number

Severity
1Minor eventNo consequences; delay in execution of the test
2Moderate eventLess effective communication of positive result; request for test to be repeated
3Major eventFailure in the communication of a negative result; subjects not taking the test receive a result communication (damage of trust in the programme); lack of informed consent
4Catastrophic eventFalse negative; failure in communication of a positive result
Detection
1CertainThe error can certainly be detected and corrected
2HighHigh possibility of error being detected and corrected
3MediumModerate possibility of error being detected and corrected
4RemoteThere is no or only a remote possibility of the error being detected and corrected
Occurrence
1Remote<1/10 000
2Very lowBetween 1/10 000 and 1/1000
3LowBetween 1/1 000 and 5/1000
4ModerateBetween 5/1000 and 1/100
5HighBetween 1/100 and 5/100
6Very high>5/100