The selection of patients for excretory urography.

Symptoms, signs, and laboratory findings that indicated excretory urography in 1,622 patients, were compared with the radiographs. The chance that an indication would be associated with demonstrable disease was calculated. No "low-likelihood" indications could be identified. Elimination of the urograms obtained for any of the indications would not have been possible without simultaneously precluding detection of many diseased patients. The monetary cost of case-finding was low, and the efficacy of patient referral high.