Overtesting for Diabetes Tends to Reap Negative “Rewards”

Researchers report a US national trend toward overtesting of glycated hemoglobin (HbA1c) levels in adult patients with Type 2 diabetes, leading to unnecessary cost, time, and other burdens for patients and providers, as well as potential patient health complications due to overtreatment with hypoglycemic drugs.

A new study led by Mayo Clinic (Rochester, MN, USA) researchers has shown that patients with Type 2 diabetes are often tested much more frequently than clinically indicated. Type 2 diabetes monitoring and treatment protocols are not well defined by professional societies and regulatory bodies. While lower thresholds of testing frequencies are often discussed, the upper boundaries are rarely mentioned. Yet, most agree that checking 1–2 times/year should suffice for adult patients who are not using insulin, have stable glycemic control within the recommended targets, and have no history of severe hypoglycemia or hyperglycemia. Yet, in practice, there is a much higher prevalence of excessive testing.


Upon examining a national cohort of 31,545 non-pregnant adults with controlled non-insulin-treated Type 2 diabetes, the investigators said the study provides definitive evidence of such excess testing. The patient cohort examined was derived from the OptumLabs Data Warehouse (OLDW) using de-identified administrative, pharmacy, and laboratory data from 2001 to 2011. Approximately 55% achieved and maintained the recommended less than 7% HbA1c level and were tested 3–4 times/year; 6% were tested 5 or more times.

“Our findings are concerning, especially as we focus more on improving the value of care we deliver to our patients—not only ensuring maximal benefit, but also being mindful of waste, patient burden, and healthcare costs,” said study lead investigator Rozalina McCoy, MD, Mayo Clinic, “As providers, we must be ever vigilant.”

“Potential reasons for more frequent testing include clinical uncertainty; misunderstanding of the nature of the test—that is, not realizing that HbA1c represents a 3-month average of glycemic control; or a desire for diagnostic and management thoroughness,” said Dr. McCoy, “Other times, it may be the result of fragmentation of care (more than one unconnected provider); the need to fulfill regulatory demands, such as public reporting of performance metrics; or internal tracking of performance. “Because our culture often thinks that more is better” patients and providers may favor additional testing due to a desire for comprehensive care, she added.

The researchers also found that excessive testing increased the odds of overtreatment with one or more drugs, despite normal HbA1c levels, and that rates of overtesting were lower among patients receiving bundled testing (i.e., cholesterol, creatinine, and HbA1c tests in the same day).

“We hope that these findings will help inform decision-making,” said Dr. McCoy.

The study was published December 8, 2015, in the British Journal of Medicine.

Related Links:
Mayo Clinic
Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery
OptumLabs