Nearly half of patients with stable A1c, who do not use insulin, found to be unnecessarily tested three to four times a year.
Glycated hemoglobin (HbA1c) has been a tool to monitor a patient’s diabetic state. According to the American Diabetes Association, a patient’s A1c goal is to be below or around 7% to reduce microvascular complications or macrovascular disease. In patients with stable or controlled diabetes, current guidelines recommend testing once or twice annually. However, more frequent A1c monitoring is needed in patients with variable glycemic control, on intensive insulin therapy, or need strict regulated control, such as pregnant women. Guidelines currently do not give any guidance on the implications of excessive testing due to a lack of evidence that excessive testing causes patient harm.
A study from the Veterans Affairs Administration found that among patients who are newly diagnosed with diabetes, 38% were tested at least three times and 4.2% were tested at least five times during their first year. Patients with stable or controlled disease, testing more than the recommended once or twice annually may not receive a benefit from the testing, which may also contribute to healthcare cost, resources, and treatment burden. Patients teting five or more times a year is redundant due to A1c being a measure of average blood glucose over three months. Over testing may cause overtreatment, which puts the patient at harm for hypoglycemia, increased healthcare cost, and potential adverse effects.
A national cohort study looking at 31,545 patients from January 1, 2001 to December 31, 2011 investigated the extent of excessive A1c testing among adults with type 2 diabetes. All patients in the study had to be at least 18 years old and had two consecutive A1c tests that were below 7% within a 24-month period. The patients averaged 58 years old with a mean A1c of 6.2%. The study found that 54.5% of patients with stable A1c received testing three to four times a year with 5.8% receiving excessive testing of five or more times a year. The likelihood of treatment intensification increased as frequency of testing increased despite the patient having stable A1c. The implication of overtreatment raises concerns of direct patient harm. Overtreatment is linked in previous clinical trial data to adverse outcomes such as hypoglycemia, cardiovascular events, and mortality.
There could be several reasons as to why providers excessively test their patients. Some potential reasons for excessive treatment could be lack of knowledge that A1c represents three months of glycemic control, desire for thoroughness of care, inadequate coordination of care between multiple providers, or even fulfilling institutional protocols. The cohort study found that as the number of doctors seen per year increased, the number of A1c tests increased accordingly. The cohort found that patients with high underlying disease burden were more likely to be tested excessively despite having stable A1c. This could be explained by the nature of specialist’s work. Specialists are also more likely to see patients who need more frequent testing, thus, are more accustomed to test for A1c for thoroughness.
The link between over testing and potential overtreatment in patients with stable A1c is concerning. The study shows a way to reduce healthcare cost as well as improve patient care. Patients and healthcare providers should assess the value of routine tests and physicians should be cautioned against excessive frequency of testing in adults with stable type 2 diabetes. By reducing tests in stable patients, healthcare waste could be reduced as well as increasing patient safety.
- The American Diabetes Association recommends testing once or twice annually in stable diabetic patients with A1c of 7% or lower.
- Study shows that 54.5% of stable diabetic patients are tested three to four times a year while 5.8% are tested excessively, five or more times a year.
- Excessive testing is a burden on healthcare as well as patient care. Excessive testing is associated with overtreatment, which can result in hypoglycemia, cardiovascular events, and mortality.
Publisher’s Note: The A1c test is a 90-120 average blood glucose result, but what most medical personnel do not realize is that 50% of the result comes from the last 30 days, so therefore it is much more sensitive to the current time. And because the HbA1c test is so important for determining the risk for serious complications, why not let your patient know what their A1c is so it can motivate your patient to better control.
Laxmisan A, Vaughan-Sarrazin M, Cram P. Repeated hemoglobin A1C ordering in the VA health system. Am J Med2011;124:342-9.
McCoy R, Van Houten H., et al. “ HbA1c overtesting and overtreatment among US adults with controlled type 2 diabetes,.” BMJ 2015;351:h6138