SENSITIVITY AND COST MINIMIZATION ANALYSIS OF RADIOLOGY VERSUS OLIVE PALPATION FOR THE DIAGNOSIS OF HYPERTROPHIC PYLORIC-STENOSIS

Background/Purpose: Two strategies are commonly used for the initial d iagnosis of hypertrophic pyloric stenosis (HPS): (1) physical examinat ion and (2) radiologic evaluation using upper gastrointestinal series (UGI) or sonography. The authors wished to determine the sensitivity a nd relative cost of each strategy. Methods: The charts of 234 patients presenting over 3 years with a history suggestive of HPS were reviewe d retrospectively. Cost, expressed as mean diagnostic charges (MDC) an d mean total charges (MTC), was calculated according to two theoretica l models. In model A, all patients first are examined by a surgeon. If an olive is palpable, they proceed to surgery. If not, they are sent to radiology. In model B, all patients have radiologic investigation f irst, and then surgical evaluation if the study result is positive. Re sults: Of the 234 patients, 150 had HPS (64%). Olives were appreciated in 111 of these (palpation sensitivity of 74%). There was one false-p ositive olive (0.7%) and no false-negatives. Sonography and UGI were e qually accurate (sensitivity of 100%, 0.5% false-positive). Equations were generated to estimate MDC and MTC for our patient population unde r each model. In model A, MDC = $507 - ($221 x palpation sensitivity) and MTC = $2,543 - ($240 x palpation sensitivity). In model B, MDC = $ 449 and MTC = $2,454, and costs were independent of ability to feel an olive. When cost was plotted against palpation sensitivity, model A y ielded a lower MDC than model B if palpation sensitivity was at least 26%, and a lower MTC if palpation sensitivity was at least 37%. Becaus e our palpation sensitivity was 74%, approximately $100 per patient wo uld be saved by sending all infants suspected of having HPS to a surge on for examination as an initial step. Conclusions: Although highly se nsitive, imaging is superfluous if an olive is palpable. Children susp ected of having HPS should have a surgical consultation before a radio logy study as long as the surgeon's palpation sensitivity for an olive is at least 37%. Improved palpation skills will result in maximum fin ancial savings. J Pediatr Surg 33:913-917. Copyright (C) 1998 by W.B. Saunders Company.