Mismatch between suspected pyelonephritis and microbiological diagnosis: a cohort study from a UK teaching hospital.

Urinary tract infections are a common reason for prescribing empirical antibiotics in the emergency department. This study investigated the role of microbiological culture and urinalysis in the diagnosis of pyelonephritis by extracting data on 105 patients with a clinical diagnosis of pyelonephritis at a London teaching hospital. In total, 99 of 102 patients were treated empirically with intravenous antibiotics, but only 55 of 100 patients who were sampled had microbiological evidence of infection in urine and/or blood. Almost half (10/21) of the patients with a negative urine dipstick test had a positive urine culture. Diagnostic uncertainty in this context undoubtedly drives inappropriate antibiotic use.