Team effect on variation in laboratory utilization on subspecialty services.

BACKGROUND The objective was to determine whether variation in laboratory utilization exists and whether physicians were responsible for a portion of this variation. METHOD Variation in laboratory test ordering was collected on subspecialty services: the Medical Intensive Care Unit (MICU) and the Oncology Service. Ordinary least-squares regression was used to determine the effect of interns, residents, and attendings on the variation observed. RESULTS Variation in laboratory utilization attributable to physicians exists. Housestaff explain a proportion of this variation on each subspecialty service. CONCLUSIONS Housestaff explain a large proportion of laboratory utilization attributable to physicians. This may represent an opportunity for education on systems-based practice and practice-based learning.