Print Continuous or Intermittent Monitoring of Glucose in the Interstitial Fluid

Continuous or Intermittent Monitoring of Glucose in the Interstitial Fluid

 

DESCRIPTION

Tight glucose control in patients with diabetes has been associated with improved outcomes. Several devices are available to measure glucose levels automatically and frequently (e.g., every 5 to 10 minutes). The devices measure glucose in the interstitial fluid and are approved as adjuncts to traditional self-monitoring of blood glucose levels.

The advent of blood glucose monitors for use by patients in the home over 20 years ago revolutionized the management of diabetes. Using fingersticks, patients could monitor their blood glucose level both to determine the adequacy of hyperglycemia control, but to also evaluate hypoglycemic episodes. Tight diabetic control, defined as a strategy involving frequent glucose checks and a target hemoglobin A1c (HgA1c) in the range of 7%, is now considered standard of care for diabetic patients. Randomized controlled trials (RCTs) of tight control have demonstrated benefits for type I diabetics in decreasing microvascular complications. The impact of tight control on type II diabetic patients and on macrovascular complications such as stroke or myocardial infarction is less certain..

However, tight glucose control requires multiple measurements of blood glucose each day (i.e., before meals and at bedtime), a commitment that some patients may be unwilling or unable to meet. In addition, the goal of tight glucose control has to be balanced with an associated risk of hypoglycemcia. An additional limitation of periodic self-measurements of blood glucose is that glucose values are seen in isolation and trends in glucose levels are undetected. For example, while a diabetic's fasting blood glucose level might be within normal values, there might be undetected hyperglycemia postprandially, leading to elevated hemoglobin A1C values.

Recently, measurements of glucose in interstitial fluid have been developed as a technique of automatically measuring glucose values throughout the day, producing data that show the trends in glucose measurements, in contrast to the isolated glucose measurements of the traditional blood glucose measurements. Although devices measure glucose in interstitial fluid on a periodic rather than a continuous basis, this type types of monitoring is referred to as continuous glucose monitoring (CGM).

Several devices have received U.S. Food and Drug Administration (FDA) approval. The first two approved devices were the Continuous Glucose Monitoring System (CGMS®) (MiniMed), which uses an implanted temporary sensor in the subcutaneous tissues, and the GlucoWatch G2® Biographer, an external device worn like a wristwatch that measures glucose in interstitial fluid extracted through the skin with an electric current (referred to as reverse iontophoresis).

Additional devices that have subsequently been approved include those for pediatric use and those with more advanced software, more frequent measurements of glucose levels, more sophisticated alarm systems, etc. Devices initially measured interstitial glucose every 5 to 10 minutes and, with currently available devices the time intervals at which interstitial glucose is measured ranges from every 1-2 minutes to 5 minutes. While continuous glucose monitors potentially eliminate or decrease the number of required daily fingersticks, it should be noted that, according to the FDA labeling, monitors are not intended to be an alternative to traditional self-monitoring of blood glucose levels but rather provide adjunct monitoring, supplying additional information on glucose trends that are not available from self-monitoring. In addition, it is important to note that devices may be used intermittently, e.g., time periods of 72 hours, or on a long-term basis.

In addition to stand-alone continuous glucose monitors, several insulin pump systems have included a built-in CGM. This policy addresses continuous glucose monitoring devices, not the insulin pump portion of these systems. Also, under development is what is known as an artificial pancreas or artificial pancreas device system (APDS). The proposed artificial pancreas is a series of devices e.g., a CGM, blood glucose device and an insulin pump, plus a computer algorithm that communicates with all of the devices. The goal of the APDS is to automatically monitor glucose levels and adjust insulin levels. These systems are also called closed-loop systems or autonomous systems for glucose control. One technology associated with artificial pancreas development is a “low glucose suspend (LGS)” feature included with an insulin pump. The LGS feature is designed to suspend insulin delivery when plasma glucose levels fall below a pre-specified threshold.

Several continuous glucose monitoring systems have been approved by the FDA through the premarket approval process:

  • The Continuous Glucose Monitoring System (CGMS®) (MiniMed) in 1999 (approved for 3-day use in a physician's office).
  • The GlucoWatch G2® Biographer in 2001. Of note, neither the GlucoWatch nor the autosensors have been available after July 31, 2008.
  • The Guardian®-RT (Real-Time) CGMS (Medtronic, MiniMed) in July 2005. (MiniMed was purchased by Medtronic).
  • The DexCom® STS CGMS system (DexCom) was approved by the FDA in March 2006.
  • The Paradigm® REAL-Time System (Medtronic, MiniMed) was approved by the FDA in 2006. This system integrates a continuous glucose monitor with a Paradigm insulin pump. The second generation integrated system is called the MiniMed Paradigm Revel System.
  • The FreeStyle Navigator® CGM System (Abbott) was approved in March 2008.
  • The OmniPod® Insulin Management System (Insulet Corporation), integrating the Freestyle Navigator CGM system with the Pod insulin pump, was approved in December 2011.
  • The DexCom G4 Platinum (DexCom) CGM was approved for use in adults 18 years and older in October 2012. The device can be worn for up to 7 days. In February 2014, FDA expanded use of the Dexcom Platinum CGM to include patients with diabetes, age 2 to 17 years-old.

 Artificial pancreas device systems:

  • The Minimed 530G System (Medtronic) integrating an insulin pump and glucose meter, and including a low glucose suspend feature, was cleared for marketing in September 2013. The threshold suspend tool temporarily suspends insulin delivery when the sensor glucose level is equal to or lower than a preset threshold within the 60 mg/dL to 90 mg/dL range. When the glucose value reaches this threshold, an alarm sounds. If patients respond to the alarm, they can choose to continue or cancel the insulin suspend feature. If patients fail to respond to the alarm, the pump automatically suspends action for 2 hours, and then insulin therapy resumes. The device is approved only for use in patients 16 years and older.

POLICY

Intermittent monitoring, i.e., up to 72 hours, of glucose levels in interstitial fluid may be considered medically necessary in patients with type I diabetes mellitus whose diabetes is poorly controlled, despite current use of best practices (see Policy Guidelines). Poorly controlled type I diabetes mellitus includes the following clinical situations: unexplained hypoglycemic episodes, hypoglycemic unawareness, suspected postprandial hyperglycemia, and recurrent diabetic ketoacidosis.

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

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

  • Patients with type I diabetes who have recurrent, unexplained, severe (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 postprandial hyperglycemia, and recurrent diabetic keoacidosis.

Other uses of continuous monitoring of glucose levels in interstitial fluid as a technique of diabetic monitoring are considered investigational.

Use of an artificial pancreas system, including but not limited to closed-loop monitoring devices with low-glucose suspend (LGS) features, are considered investigational.

 

POLICY EXCEPTIONS

Federal Employee Program (FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.

 

POLICY GUIDELINES

Several insulin pump systems (e.g., Omnipod Insulin Management System, Paradigm REAL-Time System) have a built-in continuous glucose monitor (CGM). This policy is evaluating the CGM-device only; the policy does not evaluate insulin pumps.  Insulin pumps are addressed in the External Infusion Pumps policy.

Best practices in diabetes control for patients with type I diabetes include compliance with a regimen of 4 or more fingersticks each day and 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.

Women with type I diabetes who are pregnant or about to become pregnant with poorly controlled diabetes are another subset of patients to whom the policy statement on intermittent monitoring may apply.

Intermittent monitoring is generally conducted in 72-hour periods. It may be repeated at a subsequent time depending on the patient's diabetes control.

Investigative service is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized by certifying boards and/or approving or licensing agencies or published peer review criteria as standard, effective medical practice for the treatment of the condition being treated and as such therefore is not considered medically necessary.

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.

 

POLICY HISTORY

2/2001: Approved by Medical Policy Advisory Committee (MPAC)

4/2/2001: CPT code 84945 and ICD-9 procedure code 99.99 deleted. ICD-9 diagnosis code 250.23 and 250.33 added.

2/15/2002: Investigational definition added

2/25/2002: Code Reference, Sources and Place of Service sections updated

3/13/2002: E0609 deleted, 92950 (typo) should have been 95250, 99091 moved to non-covered

4/18/2002: Type of Service and Place of Service deleted

4/17/2003: FDA approved labeling for the GlucoWatch "first bullet" expanded to include children/adolescents (age 7 to 17)

6/12/2003: Clarification of changes 4/17/2003. GlucoWatch® G2™ Biographer (G2™ Biographer) information added to Description section.

9/5/2003: Policy reviewed, no changes

10/16/2003: GlucoWatch clarification statement added to "Policy" section

1/27/2004: Sources updated

2/10/2004: Sources updated

11/3/2004: Code Reference section reviewed, no changes

3/13/2006: Coding updated. CPT4 2006 revisons added to policy

3/20/2006: Policy reviewed, no changes

3/27/2007: Policy reviewed and updated. Covered codes table deleted. CPT codes 95250, 95251, and HCPCS S1031 moved to non-covered. Removed the following policy statement, "Continuous monitoring of glucose in the interstitial fluid is considered investigational except for patients with type 1 diabetes who have not achieved adequate glycemic control in spite of frequent self-monitoring of fingerstick blood glucose levels. BCBSMS will only approve the MiniMed monitoring system. Usage of which will be for a finite period of time (Rental)."

7/19/2007: Reviewed and approved by MPAC

12/17/2007: Coding updated. CPT/HCPCS 2008 revisions added to policy.

4/25/2008: Policy reviewed, description section updated

12/31/2008: Code reference section updated per the 2009 CPT/HCPCS revisions

1/8/2009: Policy reviewed and updated. Policy statement updated to allow intermittent monitoring in patients with type I diabetes whose diabetes is poorly controlled, prior to insulin pump initiation to determine basal insulin levels and according to best practice guidelines. Policy guidelines updated to include Best Practice guidelines.Codes updated to reflect covered codes.

04/26/2010: Added “or Intermittent” to the policy title. Policy description and statement unchanged.  FEP verbiage added to the Policy Exceptions section. Deleted outdated references from the Sources section.

04/20/2011: Policy reviewed; no changes.

04/26/2012: Policy reviewed; policy statement unchanged. Policy guidelines updated to state the following:  Several insulin pump systems (e.g., Omnipod Insulin Management System, Paradigm REAL-Time System) have a built-in continuous glucose monitor (CGM). This policy is evaluating the CGM-device only; the policy does not evaluate insulin pumps. Insulin pumps are addressed in the External Infusion Pumps policy.

09/03/13: Added the following investigational policy statement: Use of an artificial pancreas system, including but not limited to closed-loop monitoring devices with low-glucose suspend (LGS) features, are considered investigational. Deleted "symptomatic" from the first bullet in the third policy statement. Intent of policy statement unchanged.

04/23/14: Policy reviewed; description updated regarding available devices. Added "mellitus" to the first policy statement. Intent of policy statement unchanged.

 

SOURCE(S)

Blue Cross Blue Shield Association Policy # 1.01.20

 

CODE REFERENCE

This may not be a comprehensive list of procedure codes applicable to this policy.

The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.   

Covered Codes

Code Number

Description

CPT-4
95250Ambulatory continuous glucose monitoring of interstitial tissue fluid via a subcutaneous sensor for a minimum of  72 hours; sensor placement, hook-up, calibration of monitor, patient training, removal of sensor, and printout of recording  
95251Ambulatory continous glucose monitoring of interstitial tissue fluid via a subcutaneous sensor for a minumum of  72 hours; interpretation and report 
99091Collection and interpretation of physiologic data (e.g., ECG, blood pressure, glucose monitoring) digitally stored and/or transmitted by the patient and/or caregiver to the physician or other qualified healthcare professional, requiring a minimum of 30 minutes' time. 
ICD-9 Procedure
  
ICD-9 Diagnosis
250.00-250.93 Diabetes mellitus range of codes

HCPCS

A9276Sensor; invasive (e.g. subcutaneous), disposable, for use with interstitial continuous glucose monitoring system, one-unit = 1 day supply
A9277Transmitter; external, for use with intersititial continous glucose monitoring system 
A9278Receiver (monitor); external, for use with interstitial continuous glucose monitoring system
S1030Continuous noninvasive glucose monitoring device, purchase (for physician interpretation of data, use CPT code) 
S1031Continuous noninvasive glucose monitoring device, rental, including sensor, sensor replacement, and download to monitor (for physician interpretation of data, use CPT code) 

 

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