Advice

The technology

The technology

The Dexcom G6 continuous monitoring system (Dexcom Inc) measures interstitial fluid glucose levels. The G6 system consists of 3 key parts: the sensor wire, a transmitter, and a display device. The display device can be either the Dexcom receiver or an app that can be used on a compatible Android or iOS smart device.

The sensor comprises a water-resistant sensor pod that is worn on the skin, and the sensor wire that is inserted under the skin using the single-use applicator. The sensor can be worn for 10 days and continuously measures glucose levels. All users may wear the sensor on their abdomen or on the back of their upper arm. Children aged 2 to 17 years can also choose to wear it on their upper buttocks.

The transmitter is a multiple-use device that attaches to the sensor pod and sends glucose information to the display device (a smart device or dedicated receiver) using Bluetooth. The transmitter must be discarded after 3 months of use. During normal use, interstitial glucose concentration estimates are sent from the transmitter to the receiving device at 5‑minute intervals and can be checked at any time. Alerts can be set to respond when glucose levels or rates of change go outside of the healthy range. This is to help people manage both hyperglycaemia and hypoglycaemia.

The G6 software app is downloaded onto the compatible smart device, which must be paired with the transmitter before use. The app continuously and automatically sends data to the Dexcom remote server, where the data are processed for reporting by the CLARITY diabetes management software. To display the data, the smart device needs to be connected to the transmitter by Bluetooth and have the Dexcom G6 app running. Dexcom receivers store 30 days of readings and need connection to a computer to upload the data to the server periodically.

The user can choose to share glucose levels, trend information and alerts with others such as carers or family members who can view data by downloading the Dexcom Follow app. The Follow app can receive alerts, for example, if the user's glucose level falls outside of the healthy range. The user can also email data reports to healthcare providers or allow them to view their data through the CLARITY software. The Dexcom CLARITY mobile app can send a weekly push notification summarising weekly time-in-range, how the user's current week compares with the previous week, and any high or low glucose patterns.

Innovations

The Dexcom G6 has an alert function. The 'urgent low' alert cannot be deactivated. This alert notifies the user when the glucose level falls to 55 mg/dl or below (defined as a severe hypoglycaemic event). An 'urgent low soon' alert notifies the user if the glucose level is predicted to drop to 55 mg/dl within 20 minutes. This alert can be turned off.

The Dexcom G6 has been designed to communicate with other digitally connected devices (interoperable), including automated insulin pumps. This allows 'hybrid artificial pancreas' systems to be created from separate devices. The Dexcom G6 can work with either the Diabecare R (DANA) insulin pump or the Tandem t:slim X2 (Tandem) insulin pump.

The company states that unlike previous versions of the technology, the Dexcom G6 factory-calibrated sensor does not need daily calibration with finger-prick blood samples. Also, unlike earlier-generation Dexcom systems, G6 readings remain unaffected by routine doses of paracetamol (a maximum of 1,000-mg dose of paracetamol every 6 hours).

Current care pathway

NICE guidelines state that people with diabetes should be empowered to self-monitor their blood glucose, and be educated about how to measure it and interpret the results. Routine blood glucose testing is typically done using a finger-prick capillary blood sample. Currently, continuous monitoring of interstitial fluid glucose levels using a continuous glucose monitor is not recommended for routine use but can be considered for some people.

The following publications have been identified as relevant to this care pathway:

Population, setting and intended user

Dexcom G6 is intended to be an alternative to routine finger-prick blood glucose monitoring for people aged 2 and over, including pregnant women, who have type 1 or type 2 diabetes, have multiple daily injections of insulin or use insulin pumps and are self-managing their diabetes. Dexcom G6 is not indicated for people who are on dialysis or critically ill. Finger-prick blood glucose testing may still be needed if the user's symptoms do not match Dexcom G6 readings or if the user is taking hydroxyurea. The company notes that because the effect of airport scanners on the G6 is unknown, finger-prick blood glucose testing should be used when the user is walking through airport security screening areas. The Dexcom G6 should not be used during MRI, CT or high-frequency electrical heat (diathermy) treatment.

The Dexcom G6 is primarily for people at home as they go about their normal daily activities. Healthcare professionals can review data from the Dexcom G6 remotely using the CLARITY software.

The company provides free access to online training videos, documents and a telephone support service for users. Training and education are also provided free of charge to healthcare professionals, including supplying appropriate supporting materials if needed.

Costs

Technology costs

The company has provided a tiered pricing model for Dexcom G6, based on number of new patients per payer. These costs include all of the sensors and applicators needed for each patient. They do not include the optional Dexcom receiver, which costs £290. In the UK, 6% people using Dexcom G6 use the receiver. Unit costs were not provided.

Dexcom G6 pricing model:

  • 1 to 4 new patients: standard price per patient per year £2,645

  • 5 to 19 new patients: £2,500 per patient per year (5.5% discount on standard cost)

  • 20 to 49 new patients: £2,200 per patient per year (16.8% discount on standard cost)

  • more than 50 new patients: £2,000 per patient per year (24.4% discount on standard cost)

  • more than 250 new patients: £1,850 per patient per year (30.06% discount on standard cost).

People using the Dexcom G6 may also need occasional use of a blood glucose monitor, with test strips and lancets. The costs for blood glucose monitoring starter kits available through the NHS range from £14.93 for 1 blood glucose meter and 10 glucose strips, lancets and a lancing device, to £107.85 for 1 blood glucose meter and 900 glucose strips and lancets. Blood glucose meters are generally provided to the patient at no cost, whereas test strips and lancets are available on prescription at various tariff prices. Costs of blood glucose test strips to the NHS vary according to the meter used but are typically between £7 and £16 for a pack of 50, with bulk-buy savings available and total cost depending on the meter chosen.

Costs of standard care

Currently, standard blood glucose meters and test strips are used to manage blood glucose levels. Flash glucose monitoring is another technology that is intended as an alternative to routine blood glucose monitoring. As an example of flash glucose monitoring, the company's website for Freestyle Libre advises that FreeStyle Libre costs £48.29 for the reader. It has a 3-year lifespan, and costs £48.29 for each sensor, which must be replaced every 14 days (equalling £1,271.64 per year). Diabetes UK advises that the current retail cost for FreeStyle Optium blood glucose test strips is £17.10 for 50 strips. FreeStyle Optium blood ketone test strips cost £21.90 for 10 strips. The FreeStyle lancets for taking finger-prick blood cost 3.9p each. Costs are excluding VAT.

Resource consequences

The company states that over 10,000 adults and children across the UK have received NHS funding for Dexcom continuous glucose monitors, and over 5,000 others pay for Dexcom monitors themselves. Access to continuous glucose monitoring (CGM) systems can vary significantly between clinical commissioning groups (Perera et al. 2018).

Resource consequences of the Dexcom G6 device have been reported by Roze et al. (2020). An economic analysis with an NHS perspective was done using the IQVIA CORE Diabetes Model to ascertain the cost effectiveness of real-time CGM with Dexcom G6 compared with self-monitoring of blood glucose alone. Clinical input data were sourced from the DIAMOND trial (Beck et al. 2017) for adults with type 1 diabetes.

Relative to self-monitoring of blood glucose, the use of Dexcom G6 resulted in 1.49 quality-adjusted life years (QALYs) incrementally, and total costs were £14,234 higher than self-monitoring of blood glucose (mean £102,468 compared with £88,234). This gave an incremental cost-effectiveness ratio of £9,558 per QALY gained.

There are no practical difficulties or changes in facilities and infrastructure associated with adopting the technology.