Guideline report. Projecting MRI utilization: two new approaches.

In today's competitive marketplace, hospitals must carefully analyze the financial impact of acquiring new technologies. The high cost of magnetic resonance imaging (MRI), one of the most prominent new technologies, makes it critical for hospitals to evaluate thoroughly the financial risks of providing this service. To determine whether it is likely to generate a sufficient number of MRI scans to break even financially, a hospital must carefully analyze its patient case mix. In 1984, the American Hospital Association (AHA) developed a method, the AHA MRI Utilization Model, for performing such an analysis. The original AHA model projected a hospital's potential demand for MRI procedures based on an analysis of that hospital's inpatient discharge data. The widespread use of the original AHA MRI Utilization Model by over 500 hospitals and a number of state health planning agencies has significantly influenced the diffusion of MRI throughout the United States. The original AHA model had several limitations, however: it ignored scans that might be performed to evaluate secondary diagnoses; its estimate of follow-up scans and replacement of CT by MRI was based on information from 1978; and it lacked a mechanism for considering outpatient scans. These limitations, together with the rapid evolution in clinical applications for MRI, led the AHA to improve its original MRI utilization projection methodology. In 1986, the AHA developed a new second generation MRI Utilization Model that employs two independently derived methodologies. The AHA's revised ICD-9-CM Projection method was developed by Richard diMonda, M.S.B.M.E., M.B.A.; the Diagnosis Related Groups (DRG) Projection Method was developed by Earl P. Steinberg, M.D., M.P.P. The second generation model has several advantages over the original model: it utilizes the opinions of a greater number of experts, as well as experts from more varied backgrounds; experts' opinions were obtained in 1986, rather than 1984, and so are more relevant to current patterns of practice; experts' opinions are employed to project CT, as well as MRI volume when both technologies are available, and the extent to which MRI will replace CT; total inpatient and outpatient scans are calculated; and hospital-specific adjustment factors are used to adjust for variations in patterns of practice across institutions. The DRG projection method also adds the ability to consider MRI and CT scans used to evaluate comorbid conditions and complications, as well as scans performed on patients who turned out to have no pathology. In addition, the DRG method provides a projection of potential MRI and CT volume in 1990, as well as currently.