Abstract: A healthcare computer system, the computer system comprising a communications module, a string generation module, a one-way function module and an anonymised data generation module. The communications module is configured to receive one or more healthcare data packets, each healthcare data packet including: data pertaining to one or more medical analytical tests performed on a sample; a sample identifier, identifying the sample; and a timestamp, indicating when the analytical test(s) was performed. The string generation module is configured to generate a string based on the sample identifier and the timestamp. The one-way function module is configured to apply a one-way function to the generated string to generate an anonymised sample identifier. The anonymised data generation module is configured to generate an anonymised healthcare data packet including the data pertaining to the one or more medical analytical tests and the anonymised sample identifier.