Cost-effectiveness in diagnosing infantile hypertrophic pyloric stenosis

PURPOSE: The purpose of this study was to determine which imaging study, upper gastrointestinal series (UGI) or abdominal ultrasonography (US), is more cost-effective in diagnosing infantile hypertrophic pyloric stenosis (IHPS) using a decision analysis model. METHODS: Probabilities were calculated from a review of the records of all infants less than 6 months of age referred for UGI or US to rule out IHPS over a 3-year period from January 1992 to December 1995. Cost-effectiveness was determined from hospital charges for each imaging study and its possible outcomes. RESULTS: The positive predictive value of UGI was 1.0 and US was 0.98 in the 246 infants evaluated for possible IHPS. In patients who had an initially normal study finding (UGI or US), 25% of patients undergoing US first required a second study for persistent symptoms, whereas only 6% of patients who had a negative initial UGI finding required a second study. CONCLUSIONS: Cost analysis found UGI to be more cost-effective than US because fewer secondary studies were required. UGI provides information regarding other pathological conditions as compared with US.