Urine cultures are the most commonly performed microbiology test at the Oxford University Hospitals but clinical impression is that many of these tests may be unnecessary. IORD provides an opportunity to see if we can answer clinical questions about the value of tests such as urine cultures for clinical management using routinely collected data. We will investigate whether the results of a urine test (negative, positive for a plausible infecting microbe, positive but only with a probable contaminant) have any impact on subsequent mortality, adjusting for co-morbidities and factors influencing whether or not tests are requested in the first place. We will see whether the main diagnosis (reason the patient came to hospital) is an independent predictor of poor outcome. We will explore whether it is possible to identify high- and low- risk subgroups based on urine test results which could enable better targeting of different management approaches in future.