Usefulness of routine urine analysis in medical outpatients

To investigate prospectively the value of routine urine analysis in a university based, medical outpatient clinic providing primary (> 90%) and referral care (< 10%) in general internal medicine, as determined by whether it led to a new diagnosis requiring a change in medical management (new treatment; advice to patient; further follow up appointment).

A dipstick urine analysis was performed in 610 consecutive patients (mean (SD) age 41 (16) years) making their first clinic visit. A urinary sediment of the same specimen was examined in those patients with abnormal results for haemoglobin, leucocytes, or protein. A urine analysis was defined as routine when it was not considered indicated for diagnostic or management purposes by the resident in charge at the patients' initial clinic visit. The main outcome measures were the number and nature of new diagnoses leading to a change in patient management.

In 183 patients (30%, 95% confidence interval (CI) 27% to 34%) the urine analysis was performed as an indicated test and in 427 (70%; 95% CI 64% to 73%) as a routine test. Urine analysis was abnormal in 71 of the 427 patients (17%) in whom it had been performed as a routine test. Abnormal findings led to a change in management in three patients only (0.7%; 95% CI 0.2% to 2.2%). Critical assessment makes the value of routine urine analysis debatable even in these three patients.

In a middle aged medical outpatient group of a university based, teaching clinic providing predominantly primary care, urine analysis can be restricted to patients in whom it is clinically indicated.