Diagnosis and management of osteomyelitis. Decision analytic and pharmacoeconomic considerations

Osteomyelitis, or bone infection, is becoming more common, largely because of increases in the use of implanted prosthetic devices in the management of arthritis or fractures. The clinical management of osteomyelitis requires accurate microbiological diagnosis that will identify appropriate antibacterials to which the pathogenic organisms are sensitive. Therapy will largely depend on the type of bacteria, the route by which the bacteria reach the bone, the presence of any orthopaedic devices and the patient's ability to mount an immune response. Consequently, therapy often requires a combination of medical and surgical management. The aim of this review is primarily to assess the impact of different drug regimens on the total cost and to clarify the implications of various treatment options for patients with osteomyelitis. Thus, the review examines the link between the main categories of osteomyelitis and common pathogens, and provides additional comments on the aetiology and epidemiology of the condition. At present, there is a real shortage of high quality evidence to guide the decision-maker through the range of available options. One way to deal with the complexity and uncertainty surrounding the management of osteomyelitis is to develop treatment protocols leading to decision trees which will in turn systematically analyse the options available for treating patients with osteomyelitis. Consequently, we have developed a number of decision trees to show the range of options available and have applied these to the relatively simple problem of route of administration of antibacterials. However, even here the available data allow only relatively crude estimations of the costs and consequences of alternative regimens. Thus, the aim has been to provide structures that may help to set priorities for research based on the expected value of new information. In the absence of evidence, there are broadly 2 alternatives. One is based on selection of the least expensive regimen in the absence of evidence to prove that more expensive options are more effective; patients with multiply resistant staphylococci, for which no effective oral regimen is available, should be treated with intravenous therapy. This is consistent with the UK legal system, which is founded on the so-called Bolam test. The alternative is providing the maximum available treatment; in the US, it is more likely that a doctor will be held negligent for not providing the maximum available treatment, and most standard texts recommend routine use of intravenous therapy for osteomyelitis.