ABSTRACT
In all clinical trials of antibiotics there will be two basic criteria for the assessment of success, namely, bacteriological eradication and clinical outcome; also there may be additional secondary criteria such as change in colour of sputum or appearance of the urine. The two methods of assessing ‘cure’ in antibacterial trials, namely symptomatic and bacteriological, are quite different and must be analysed and interpreted entirely separately, the bacteriological assessment being the ‘gold standard’. There are at least two further important pitfalls to avoid. Firstly, it is well recognised that disappearance of bacteria and/or symptoms may occur in 50% of urinary-tract infections treated without an antibiotic; so these parameters of efficacy should not be blindly regarded as indicators of success. Secondly, differentiating between relapse and reinfection in the event of bacteria occurring in the ‘final specimen’ should pose no problems, but often does.
