ABSTRACT
The diagnosis of ARIs illustrates well Osier's dictum that 'Medicine is a science of uncertainty and an art of probability.' Only when antibiotics became available, shortly after World War Two, was there a reason for reliably distinguishing between viral and bacterial infection. Unfortu nately this is not easy for the acute ARIs, regardless of whether clinical judgement or diagnostic tests are used. It is clear that relying on clinical judgement alone is neither satisfactory nor precise. In Israel, Dr David Lieberman and colleagues compared serological testing of patients with an ARI with physicians' judgements of whether a virus or a bacterium had caused the infection. Clinical judgement was found to have a negative predictive value of 60% and a positive predictive value of only 50%. 'We conclude that physicians' ability to determine whether the infectious aetiology of ARI is viral or bacterial is low, and no more reliable than tossing a coin' (Lieberman et al., 2001).
