Table 1

Classification of discrepancies according to potential harm

Class 1	Discrepancies unlikely to cause patient discomfort or clinical deterioration. An example would be prescription discrepancies in timing of the dose where this was considered unimportant, or discrepancies involving drugs considered not potent (eg, some vitamins).
Class 2	Discrepancies with the potential to cause moderate discomfort or clinical deterioration. An example would be a patient given a hypnotic drug every night by the home-care services, even though it was prescribed as required in the GP's record.
Class 3	Discrepancies with the potential to result in severe discomfort or clinical deterioration. An example would be when warfarin was missing in one of the two records.
Class 0	It could not be decided with certainty whether the discrepancy was a true discrepancy or not. An example is lack of information on vitamin B₁₂ injections in the home-care service records. This could result in a patient not receiving the injection (an error); alternatively could the injection each time be given at the GP's office (no error). In the latter case, the information was not needed at the home-care services since they were not responsible for the administration of the drug.