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Less than 38% of patients receive recommended follow-up testing six months after an initial CT or MRI scan


Less than 38 per cent of Ontarians are receiving recommended follow-up testing six months after an initial CT or MRI scan. New research from the Institute for Clinical Evaluative Sciences (ICES) shows many CT and MRI reports contain suggestions for further diagnostic testing, but these suggestions are often not followed.

The study of 15,970 patients who received an outpatient CT or MRI scan in Ontario in 2005 found:

  • Further diagnostic testing was recommended in 1 in 8 (13 percent) of test reports.
  • Further diagnostic testing was recommended particularly often after CT scans of the chest (1 in 4 reports).
  • For almost two thirds of patients (62.4 percent), recommended further testing had not been done by six months after the initial CT and MRI scan.

Researchers say these findings might be explained in three different ways:

  • Radiologists reading the CT or MRI scan images were erring on the side of caution because they had not been given enough information about the patient to say with confidence that there wasn’t a serious disease present. As a result they were recommending further testing when sometimes it wasn’t necessary.
  • There may be poor continuity of care with gaps in the delivery or tracking of imaging test results.
  • Physicians, after discussing the results with their patients, may make a conscious decision not to proceed with the recommended testing because of patient preferences or the further testing is judged to be of limited use.

“In this study, we could not determine the reasons for the ‘missed testing,’ so we can't say which of the above explanations is the main driver of the patterns of care. However, we believe that improved exchange of information between physicians seeing patients and radiologists reading the scans would help improve the situation,” says principal investigator and ICES scientist, Dr. John You.

The researchers are recommending the following:

  • Use of CT/MRI requisitions (e.g., electronic or web-enabled) that ask referring physicians to provide more targeted, disease-specific information which may help radiologists give more useful information in their test reports-in most centres, a referring physician only needs to write one or two words to request the imaging test e.g., "cough.”
  • More creative solutions, such as physically situating radiologists within patient care areas (e.g., in an outpatient cancer clinic area) for peer-to-peer consultation and conversation which could facilitate better information exchange.

Author affiliations: ICES (J. You, A. Laupacis, C. Bell); Depts. of Medicine and Clinical Epidemiology & Biostatistics, McMaster University (J. You,); Dept. of Medicine and Keenan Research Centre, Li Ka Shing Knowledge Institute of St.Michael’s (A. Laupacis, A. Newman, C. Bell) and Depts. of Medicine, and Health Policy, Management and Evaluation, Faculty of Medicine, U of T. (A. Laupacis, C. Bell)

The study “Non-adherence to recommendations for further testing after outpatient computed tomography and magnetic resonance imaging” is in the June 2010 issue of the American Journal of Medicine.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.



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