C G M

Standards of Medical Care in Diabetes:
ADA Glucose Monitoring Recommendations

According to American Diabetes Association, (ADA) standards, continuous glucose monitoring (CGM) in conjunction with intensive insulin regimens can be a useful tool to lower A1C in selected adults (age = 25 years) with type 1 diabetes.

Although the evidence for A1C lowering is less strong in children, teens, and younger adults, CGM may be helpful in these groups. Success correlates with adherence to ongoing use of the device. CGM may be a supplemental tool to self-monitored SMBG in those with hypoglycemia unawareness and/or frequent hypoglycemic episodes.

Medical Criteria

Continuous Glucose Monitoring

Continuous, i.e., long-term, monitoring of glucose levels in interstitial fluid, including real-time monitoring, as a technique of diabetic monitoring, is considered medically necessary when the following situations occur despite use of best practices**:

Clinical documentation is required to support the following:

•  Patients with type I* diabetes who have recurrent, unexplained, severe, symptomatic (generally blood glucose levels less than 50 mg/dl) hypoglycemia for whom hypoglycemia puts the patient or others at risk; or:

Patients with type I* diabetes who are pregnant whose diabetes is poorly controlled. Poorly controlled type I diabetes includes unexplained hypoglycemic episodes, hypoglycemic unawareness, suspected post-prandial hyperglycemia, and recurrent diabetic ketoacidosis.

* In some patients with Type 2 diabetes, as the need for insulin rises, the pancreas gradually loses its ability to produce insulin thus resulting in Type 1 diabetes. Clinical documentation to support this (i.e., documentation of islet cell antibodies) must be submitted.

The combined use of a continuous glucose monitor AND an external insulin pump both require preauthorization (see policy “Insulin Infusion Pumps” for medically specific criteria).

Continuous glucose monitoring systems combined with an external insulin pump in a single closed-loop system is not covered as it has not been FDA approved.

Other uses (e.g., Type 2 diabetes) of continuous monitoring of glucose levels in interstitial fluid as a technique of diabetic monitoring are considered not medically necessary because there is insufficient evidence in the published medical literature to demonstrate its efficacy.

Intermittent Glucose Monitoring

Intermittent monitoring, i.e., up to 72 hours, of glucose levels in interstitial fluid is considered medically necessary in patients with type I diabetes whose diabetes is poorly controlled despite current use of best practices**. Poorly controlled type I diabetes includes the following clinical situations: unexplained hypoglycemic episodes, hypoglycemic unawareness, suspected post-prandial hyperglycemia, and recurrent diabetic ketoacidosis.

Intermittent monitoring of glucose levels in interstitial fluid is considered medically necessary in patients with type I diabetes prior to insulin pump initiation to determine basal insulin levels.


** Best practices in diabetes control for patients with type I diabetes include:

•  Compliance with a regimen of 4 or more finger sticks each day (with appropriate adjustments) and which may include the use of an insulin pump.
During pregnancy, 3 or more insulin injections daily could also be considered best practice for patients not on an insulin pump prior to the pregnancy.
Prior use of an intermittent (72-hour) glucose monitor would be considered a part of best practices for those considering use of a continuous glucose monitor.
Source: American Diabetes Association, CGM Recommendations 2011
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