Reliability assessment techniques for medical procedures

Healthcare aims to deliver good patient outcomes. However deviations in the application of medical procedures can result in failure to deliver reliable care, variation in patient results, waste of hospital resources and increase of risk to staff and patients. Venepuncture – the act of taking blood samples for laboratory tests – has been practised for centuries and is still one of the most common invasive procedures in healthcare. Each step of the procedure can affect the quality of the sample and is thus important for preventing rejection of blood specimens, patient and staff injury and even death. There is evidence that, despite published guidelines, there is wide variability in terms of the procedure, its duration and success rates. This variability can depend on numerous factors: material factors, such as equipment and tubes used during the drawing of blood, and staff factors, such as tourniquet technique and skill of the individual. If the variability effects on outcomes can be evaluated in terms of process reliability and efficiency, potential changes to the current medical practice can be tested before they are proposed and implemented. In this paper a reliability assessment technique based on engineering reliability modelling methods is proposed. A technique based on Petri nets and simulation is presented which can be used to mimic and analyse the performance of a medical procedure through graphical and probabilistic modelling features. The technique can be used to demonstrate variations in the venepuncture procedure affect the outcomes, such as reliability and the duration of the procedure. Different scenarios of resource allocation can be analysed and the most critical steps of the procedure identified. The proposed technique is illustrated using the information gained from interview and questionnaire responses from doctors and phlebotomists working in UK hospitals.