Criteria-Based Ordering Improves Vitamin D Testing

Implementing a criteria-based restriction on laboratory requisitions can sharply cut vitamin D testing, according to a study published online May 23 in JAMA Internal Medicine. The authors say that this strategy improves the clinical utility of testing without missing clinically relevant conditions.

Laboratories in Alberta, Canada noted excessive test volume for vitamin D assays, so in 2013 laboratory services decision-makers used feedback from endocrinology specialists in the province and Choosing Wisely guidelines to identify when a 25-hydroxy vitamin D assay was likely to be most clinically useful. This resulted in the development of a new laboratory services requisition form that required physicians to identify the medically necessary indication for testing vitamin D levels (metabolic bone disease, abnormal blood calcium level, malabsorption syndrome [including celiac disease, small-intestinal surgery, anticonvulsant agents], chronic renal disease, and liver disease). Other indications did not qualify for testing.

The researchers found that in the first nine months of use of the new requisition form (from April 1 to Dec. 31, 2015), 20,609 vitamin D tests were ordered. Historical data would have predicted that 256,027 tests would have been ordered during this time frame. Thus, the intervention led to a 92.0 percent reduction in the number of vitamin D tests ordered, translating to a savings of $3 million for the study period.

“Criteria-based approaches to the implementation of the Choosing Wisely recommendations have been examined in practice for other tests, including the commonly ordered tests for rheumatoid factor antibody and anti-nuclear antibodies, as well as advanced imaging,” writes co-author Robert Ferrari, M.D., from University of Alberta, Edmonton. “Using a criteria-based approach to test ordering not only reduces the number of tests that would be ordered but it does so without missing clinically relevant conditions.”

Takeaway: Criteria-based ordering can help improve the medical necessity of Vitamin D test orders, but is an applicable strategy for other over-ordered tests as well.