Recent shifts in place of service for noninvasive diagnostic imaging: have hospitals missed an opportunity?

Purpose: The aim of this study was to examine recent shifts in place of service for noninvasive diagnostic imaging (NDI) and determine whether hospitals have lost business to private outpatient imaging facilities.

Method And Materials: The nationwide Medicare Part B databases for 1996 through 2006 were used, and all Current Procedural Terminology((R)), fourth edition, codes for NDI were studied. Utilization rates per 1,000 Medicare beneficiaries were calculated. Medicare uses place-of-service codes to differentiate examinations performed in hospital inpatients, hospital outpatients, and hospital emergency departments from those performed in private office settings. Changes in utilization rates in these locations were compared over the course of the decade, with particular emphasis on possible outpatient NDI shifts between hospital outpatient departments and private offices or imaging centers. Also, Medicare physician specialty codes were used to determine whether radiologists or other specialists were more responsible for growth.

Results: Between 1996 and 2006, Medicare NDI utilization rates per 1,000 -hospital inpatients increased from 1,056.5 to 1,211.8 (+15%). Emergency department rates increased from 222.1 to 392.2 (+77%). Hospital outpatient rates increased from 793.4 to 993.2 (+25%), while private office rates went from 883.3 to 1,442.2 (+63%). Total outpatient imaging rates (both hospital and office) went from 1,676.7 to 2,435.4 (+45%). As a result of the more rapid growth in private office imaging, hospitals' share of this market dropped from 47% in 1996 to 41% in 2006. Private office imaging utilization rates between 1996 and 2006 grew by 71% among nonradiologist physicians, compared with 44% among radiologists.

Conclusion: Medicare NDI utilization rates increased in all places of service between 1996 and 2006. Growth in hospital outpatient imaging was slower than that in private imaging facilities. Because NDI can be a profitable business, it seems that hospitals have lost an important opportunity. Much of this loss of business was to nonradiologist physicians, whose private office imaging utilization rate grew considerably more rapidly than that of radiologists.