My chosen health promotion project is to investigate inequitable access to computed tomography (CT) scans in Southwestern Ontario. Although not specifically focused on wait times, I will share a critique of an environmental scan by Ferderbar et al that examines Canada’s use of diagnostic reference level (DRL) for CT imaging exams (Ferderbar et al., 2019). Radiation is known to be a weak carcinogen and Medical Radiological Technologists traditionally practice imaging to ensure the patient receives as low as reasonably achievable (ALARA) radiation dose, known as the ALARA principle (Ferderbar et al., 2019). Monitoring doses of radiation using a DRL can help guide CT practice and ensure imaging strives to limit radiation exposure for each study.
The authors employed a preferred reporting items for systematic reviews and meta-analysis (PRISMA) strategy using PubMed and MEDLINE databases. In total, eight articles from six provinces were included in the environmental scan. Having difficulty finding sufficient volumes of data for the their initial plan, the authors widened the borders of their CT study inclusion criteria to include both non-contrast and contrast-enhanced studies (Ferderbar et al., 2019). Three limitations of the study were discussed by the authors:
Different CT scan protocols, some of which by design provided higher doses of radiation, were included in the comparisons
The absence of standardization of study protocols leads to wide variance and inconsistency in DRL, even within the same health centre
Manual DRL collection in some studies can be viewed as a method prone to error
As I review this study, I will critique using a strength, weakness, opportunity and threat analysis. A strength of this paper is that, as Ferderbar et al identify, this is the first known paper that compared all provincial DRL information for comparison with recent national guidelines. However, the limited studies and inability to obtain usable data from more than six provinces, weakens the conclusions for national adherence to guidelines for the use of DRL. Since the study was prepared in 2019, there may now be additional studies on DRL published and this would present as an opportunity for follow-up to this study. Moreover, as new CT scanners are implemented, the ability to access and export the DRL data will continue to improve, removing the potential errors generated by manual data collection. Currently, other than the desire to provide an as low as reasonably achievable radiation dose to patients, there are no direct requirements that drive the on-going improvement for this topic. The urgency for continuous improvement is relatively low which threatens significant improvements to DRL performance.
Although wait times for CT scans are a focus of our provincial government and a key area of focus for diagnostic imaging leaders, I have been surprised at how few peer-reviewed studies I have located on this topic. Similarly to the limitations this environmental review, as I continue to develop my health promotion model to improve inequitable access to CT scans, I will be mindful of the limitations of current literature. I will ensure my environmental scan acknowledges the work being done in different areas of focus, such as surgery and outpatient services to address wait times and review how their improvement activities can be applied to my topic.
References
Ferderbar, M. L., Doyle, T. E., Samavi, R., & Koff, D. (2019). An Environmental Scan of the National and Provincial Diagnostic Reference Levels in Canada for Common Adult Computed Tomography Scans. Canadian Association of Radiologists Journal, 70(2), 119–124. https://doi.org/10.1016/j.carj.2018.07.005
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