Elsevier

Clinical Biochemistry

Volume 50, Issue 15, October 2017, Pages 822-827
Clinical Biochemistry

Rates of inappropriate laboratory test utilization in Ontario

https://doi.org/10.1016/j.clinbiochem.2017.05.004Get rights and content

Highlights

  • Ontario Provincial Data used to evaluate inappropriate repeat laboratory tests.

  • Nine laboratory tests with minimum time intervals demonstrate 6–20% inappropriate orders.

  • There is an opportunity to improve test ordering practice in Ontario.

  • Between 60 and 80% of tests ordered too soon were ordered by the same physician.

Abstract

Background

Medical laboratory tests ordered redundantly represent one of the targets for reducing diagnostic testing without negatively, and possibly positively, affecting patient care. We study a clearly defined category of excessive laboratory utilization for nine analytes where inappropriate diagnostic testing is defined in terms of the time interval between tests; that is, ordering a test too soon following the previous order of the same test.

Methods

Population data from the near universal public Ontario Health Insurance Plan for the years 2006–2010 are employed where the tests are fulfilled by community medical laboratories. The analytes selected for consideration are thyroid stimulating hormone, hemoglobin A1c, lipid profile, serum protein electrophoresis, immunofixation, quantitative immunoglobulins, Vitamin D, Vitamin B12, and folate.

Results

For the nine analytes studied, the percentage of inappropriate tests ranged from 6% to 20%. Large proportions of these inappropriate tests were completed > 2 weeks prior to the minimum threshold to reorder defined by practice guidelines and/or were repeated excessively within a year. Between 60% and 85% of the time, the ordering physician of an inappropriate test was the same physician who ordered the previous test. Specialists were more likely than primary care physicians to order repeat tests too soon.

Conclusions

A sizeable proportion of testing for these analytes was inappropriate according to practice guidelines. It is recommended that systems for preventing unnecessary repeat testing are investigated by the funding agencies and that reducing inappropriate testing be considered as a design element for electronic medical records and related information technology systems.

Section snippets

Background

Appropriate utilization of resources is required to ensure that health care remains sustainable and to promote the best outcomes for patients [1]. While diagnostic test utilization has long been an important issue [2], [3], [4], health care systems increasingly face challenges related to aging populations, the rapid introduction of new technology and changing educational environments for healthcare providers. Initiatives such as Choosing Wisely are highlighting relevant issues [5]. Recent

Methods

We study one clearly defined category of excessive laboratory utilization where inappropriate is defined solely in terms of the time interval between tests. The analytes selected for consideration are thyroid stimulating hormone (TSH), hemoglobin A1c (HbA1c), lipid profile, serum protein electrophoresis (SPEP), immunofixation (IFE), quantitative immunoglobulins (QI), Vitamin D, Vitamin B12, and folate. These are selected as they have generally accepted guidelines on the appropriate frequency of

Results

In Table 2 we report: the number of laboratory tests done in the province for each of the analytes listed above, tests per capita where the denominator is the population of Ontario obtained from Statistics Canada (2016, CANSIM Table 051-0001), the number and percentage of inappropriately ordered laboratory tests, the number of patients who had the test, the percentage of patients who had at least one inappropriately ordered test, and the percentage of patients with more than one inappropriately

Discussion

This study demonstrates that a large proportion of physicians (Table 3) make inappropriate orders. The widespread inconsistency with best practice guidelines highlights that some form of support is required to facilitate appropriate ordering. Similarly, a study done in Alberta finds that 16% of six laboratory tests are repeated earlier than necessary [20]. Another study from the Veterans' Administration (VA) health system in the United States found that 30% of patients being followed for

Conclusions

Relatively large proportions of the tests ordered for the nine analytes studied are inappropriate according to accepted best practice guidelines. These tests are mostly ordered by the same physician, and both primary care and speciality physicians exhibit this inappropriate testing practice. Most inappropriate repeats occur only once in the defined time frame, but multiple repeat tests are also quite common. This study demonstrates that there are areas for improvement in the ordering of medical

Acknowledgements

This research was funded by the Government of Ontario (02045). The views expressed in this paper are the views of the authors and should not be taken to represent the views of the Government of Ontario.

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