A three centre audit of IVU referrals in patients with asymptomatic microscopic haematuria

There is considerable debate concerning the investigation of patients with asymptomatic microscopic haematuria. Urine dipstick testing is a sensitive screening test but may be positive in some normal individuals. The present consensus is that urine microscopy should be performed to confirm haematuria prior to further investigation. We have performed a retrospective study to establish whether urine microscopy was used in addition to dipstick testing before a request for intravenous urography (IVU) in three centres. IVU request forms from a District General, a Teaching Hospital and a Uroradiological Referral Centre were audited over a 9-month-period. Patients referred with asymptomatic microscopic haematuria were selected. The case notes and urine microscopy results were reviewed. The date of microscopy and its result and the interval between the result and the IVU request were established. One hundred and two cases have been examined, 17 (16.7%) of which were under the age of 40. Only 37 in total had significant haematuria on microscopy and of these, 32 results (31.4% of all cases) were available before the IVU request. In eight patients there was no evidence that urine microscopy had been performed. Fourteen patients had a urinary tract infection. Our findings show that IVUs are often requested on the basis of dipstick testing alone. Only one third of patients had confirmed significant haematuria at the time of IVU request and in some patients infection had not yet been excluded. Although prompt investigation of microscopic haematuria is important, it is essential that the diagnosis is established by microscopy before an IVU is requested.