A feasibility study to derive two clinical decision rules for patients with urinary calculi: For the use of urgent intravenous pyelography and for predicting complications of delayed urinary calculus passage.

Abstract

Background. About 5--15% of the North American and European populations pass a urinary stone in their lifetime. The most accurate way of detecting degree of urinary obstruction is with a radiograph called an intravenous pyelogram or IVP. Objectives. (1) To assess the feasibility of developing a clinical decision rule that would identify the clinical factors that are sensitive in predicting which patients with suspected ureteral calculi have severe obstruction and require urgent pyelography by: (i) defining severe obstruction; (ii) determining the incidence of severe obstruction; (iii) identifying potential predictor variables; and (iv) calculating a sample size for the definitive decision rule study. (2) To prospectively assess clinical predictors of complications from urinary calculi after discharge from the ED by: (i) determining the incidence of complications; (ii) identifying preliminary predictor variables; (iii) calculating a sample size for the definitive study. (Abstract shortened by UMI.)