From quantity to quality: the central cardiac audit database project

Until the turn of the century physicians were trained as apprentices, basing patient management on experience, supported by a limited understanding of the disease process and the effects of treatment. There was no “optimal management” of disease, except that defined by the teachers in the profession, who in turn based teaching largely on anecdotes. The development of the mathematics of probability as applied to medicine,1 and the consequent introduction of the randomised clinical trial,2 has changed the basis of medical practice in many disciplines. For many common conditions, it is now possible to define contemporary optimal management of disease in terms of the probability of a defined outcome. The probabilities are usually based on evidence from clinical trials or observational studies. Clinical trials have the advantage of minimising bias and negating confounding and unanticipated variables, while observational studies have the advantage of studying usually larger and more heterogeneous populations of patients more typical of clinical practice. Cardiovascular disease causes more premature mortality and morbidity in developed countries than any other organ disease.3 4 It is appropriate that a wealth of information now exists about the common conditions to allow definition of optimal management. When practising medicine by applying the results of clinical trials and observational studies to an individual patient, there is an inherent assumption by both doctor and patient that the outcome defined by such evidence will be achieved. What is usually missing is the measurement of that outcome.5 6 On a probability basis it is likely that different medical teams will achieve significantly different results in similar groups of patients using the same treatments. It must be a prime objective of clinical audit to apply the methods of quality assurance both to improve practice in general and to identify and eliminate the lower end …