Substitution of magnetic resonance imaging for computed tomography. An exploratory study

Effect of computerized order entry with integrated decision support on the growth of outpatient procedure volumes: seven-year time series analysis

PURPOSE

To determine the effect of a computerized radiology order entry (ROE) and decision support (DS) system on growth rate of outpatient computed tomography (CT), magnetic resonance (MR) imaging, and ultrasonography (US) procedure volumes over time at a large metropolitan academic medical center.

MATERIALS AND METHODS

Institutional review board approval was obtained for this study of deidentified aggregate administrative data. The research was compliant with HIPAA; informed consent was waived. This was a retrospective study of outpatient advanced imaging utilization before, during, and after implementation of a Web-based ROE and DS system. Dependent variables were the quarterly volumes of outpatient CT, MR imaging, and US examinations from quarter 4 of 2000 through quarter 4 of 2007. Outpatient visits during each quarter were included as control variables. These data were analyzed as three separate time series with piecewise linear regression for simultaneous estimation of quarterly examination volume trends before and after ROE and DS system implementation. This procedure was repeated with log-transformed quarterly volumes to estimate percentage growth rates.

RESULTS

There was a significant decrease in CT volume growth (274 per quarter) and growth rate (2.75% per quarter) after ROE and DS system implementation (P < .001). For MR imaging, growth rate decreased significantly (1.2%, P = .016) after ROE and DS system implementation; however, there was no significant change in quarterly volume growth. With US, quarterly volume growth (n = 98, P = .014) and growth rate (1.3%, P = .001) decreased significantly after ROE implementation. These changes occurred during a steady growth in clinic visit volumes in the associated referral practices.

CONCLUSION

Substantial decreases in the growth of outpatient CT and US procedure volume coincident with ROE implementation (supplemented by DS for CT) were observed. The utilization of outpatient MR imaging decreased less impressively, with only the rate of growth being significantly lower after interventions were in effect.

Health care technology as a policy issue

Health care technology has become an increasingly visible issue in many countries, primarily because of the rising costs of health care. In addition, many questions concerning quality of care are being raised. Health care technology assessment has been seen as an aid in addressing questions concerning technology, including benefits and costs. A number of industrialized countries have developed active programs of health care technology assessment during the past two decades. Eight countries at similar levels of socio-economic and health development--Australia, Canada, France, Germany, the Netherlands, Sweden, the United Kingdom and the United States--have been examined to gain insights into how they manage health care technology and what place technology assessment has in such management. In addition to seeking general information, specific cases--treatment for coronary artery disease, medical imaging, laparoscopic surgery, treatment of end-stage renal disease, neonatal intensive care, and breast cancer screening--were examined in each country.

Magnetic resonance imaging. Diffusion of technology in an ambulatory setting

To better understand technology diffusion in an ambulatory care setting, we analyzed adult outpatients' use of magnetic resonance (MR) and computed tomography (CT) imaging in a group-model HMO between 1986 and 1989. The use of MR, but not CT, increased at a rapid pace with only a small proportion of the scans being accounted for by primary care physicians.