A bar code based computerised anaesthetic audit system is described. The system consists of a data entry and validation module resident on a remote hand-held computer and a central database module resident on a desktop computer, capable of conducting extensive searches, analysis, graphing and reporting of captured data. Information is entered into the computer by 'swiping' a bar code reader across required bar codes. Information entered is constantly validated and the computer ensures a minimum data set is captured for every patient. Since data is transferred directly into a computer at the point of clinical activity, a large data set can be presented to the clinician, ensuring as complete a patient record as possible and avoiding the problems associated with traditional form-filling and the subsequent transfer of information onto a computer. The hand-held computer has data cards which can hold information on approximately 200 patients. These cards can be inserted directly into a card reader attached to a desktop computer, thus automating the process of data transfer. The AxSys Anaesthetic Audit system, AxAudit, is a bar code based, computerised audit system developed with the aim of executing effective audit in the course of normal clinical activity.