Non-adherence to recommendations for further testing after outpatient CT and MRI

Nearly 1 in every 5 outpatient visits ends with a request for a diagnostic imaging test, and imaging reports often contain recommendations for further testing. Little is known about adherence to recommendations for further testing after outpatient computed tomography (CT) and magnetic resonance imaging (MRI).

We performed a retrospective cohort study linking provincial administrative data to a cross-sectional audit of 23,691 outpatient CT and MRI scans performed in 2005 in Ontario, Canada. After excluding patients who died (n=1031), were hospitalized (n=3030), or visited an emergency department (n=3660) within 180 days of the index CT/MRI scan, 15,970 CT/MRI scans were included. The primary outcome was adherence to recommendations for further testing within 180 days of an index CT/MRI scan.

Further testing was recommended in 2027 of 15,970 (12.7%) index CT/MRI scan reports and was recommended most frequently after CT chest scans (593 of 2276 [26.1%]). From the 2027 scans in which further testing was recommended, we identified 2102 individual recommendations for a specific type of follow-up test and found that just over one third (37.6%) of these recommendations were followed at 180 days. Adherence was lower (32.3%) when patients had a visit to the referring physician within 180 days of the index CT/MRI scan, compared with when they had no such visit (50.5%; P <.001).

Radiologists commonly recommend further testing after outpatient CT and MRI scanning. However, nearly two thirds of these recommendations are not followed. This suggests that substantial opportunities exist to improve the exchange of information between clinicians and radiologists and to advance the quality of outpatient care.