Adoption and Use of High Technology Medical Imaging in Ontario Hospitals: The Determinants of Adoption and the Relationship between Use and In-patient Mortality and Length of Stay

There is broad agreement that a substantial fraction of imaging examinations are unnecessary and do not positively contribute to patient care. The negative implications for health care quality and costs, including unnecessary exposure to radiation, resulting from unnecessary use of medical imaging have been extensively recognized in the scholarly and policy literature. Not surprisingly, the need for evidence documenting the value of medical imaging is increasingly gaining more interest. This thesis aims to address this need by investigating the value of adoption and use of CT scanners and MRI machines in hospitals operating in a universal, single-payer system. Adoption was hypothesized to be a central element of quality and efficiency, linking hospital structural characteristics and market factors with hospital outcomes. Empirical investigations focused on the determinants of adoption, and the relationship between adoption (and use) and hospital mortality and length of stay in medical in-patients. Hospital size, specialization, and financial condition emerged as consistent determinants of hospital adoption of CT and MRI technologies. Market factors, however, showed inconsistent relationships with adoption. The results also suggest that adoption reduces mortality and length of stay, and that imaging use reduces mortality and increases length of stay. The relationship between imaging use and outcome was conditional to the hospital adoption pattern or behaviour. That is, the use of imaging saves lives, but only in hospitals with at least one technology available. This was not the case in hospitals without CT and MRI technologies, where imaging scans are contracted out to other hospitals or independent health facilities. The imaging use-outcome relationships examined also suggest the existence of diminishing returns and flat-of-the-curve medicine. These results may have important implications for policy development aimed at improving the value of imaging. Some potential changes to the current funding models are discussed and delineated, including the use of financial incentive systems specific to CT and MRI services. This thesis has demonstrated the potential to inform empirical investigations of the value of high technology medical imaging, and has contributed to the literature by advancing the understanding of the mechanisms that produce quality and efficiency in hospitals.Ph.D