CGM cost-effective in T1D patients on daily insulin injections
The use of continuous glucose monitoring (CGM) may be cost-effective in patients with type 1 diabetes (T1D) receiving daily multiple insulin injections, the DIAMOND* trial has shown.
CGM tracks glucose levels in the interstitial fluid automatically every few minutes throughout the day through a tiny sensor inserted just under the skin. The beauty of the device is that it works with apps on smartphones and smartwatches. “Basically, all the CGM does is provide information, but that allows patients to change the way they eat or time their medications, and ultimately, manage their own health,” said study author Dr Wen Wan from the University of Chicago, in Chicago Illinois, US.
In the unblinded multicentre DIAMOND trial, CGM for up to 6 months was cost-effective at the willingness-to-pay threshold of USD100,000 per quality-adjusted-life-year (QALY) gained, with improved glucose control and reductions in nonsevere hypoglycaemia. Patients on CGM vs controls had significantly greater reductions in HbA1c (-1.0 vs -.04 percentage points) and nonsevere hypoglycaemic episodes (-0.12 vs -0.06, p=0.02) per day. The rates of severe hypoglycaemic episodes were comparable between the CGM group and controls (2 percent vs 4 percent, respectively). [Diabetes Care 2018;doi:10.2337/dc17-1821]
Wan said previous studies of CGM in T1D were based on the use of insulin pumps even though 6 in 10 patients still use daily multiple insulin injections. “Our study provides an important expanded view on the contemporary economic value of CGM in T1D.”
The DIAMOND trial included 158 T1D patients who had HbA1c ≥7.5 and were receiving multiple daily insulin injections, randomized in a 2:1 ratio to CGM or usual care with finger prick method (test strips and a meter) as the control. A modified Sheffield T1D policy model was used to simulate T1D complications. The main outcome was the cost per QALY gained.
Average 6-month total costs were USD11,032 for the CGM group vs USD7,236 for controls (p<0 .01), with the difference largely attributed to the cost of the CGM device at about USD2,500. The cost of daily glucose test strip was significantly reduced with CGM vs no CGM (USD612 vs USD750, p=0.04).
“When we mapped out the lifetime of a patient, it’s impressive. The CGM added years of life and years of quality life,” said senior study author Dr Elbert Huang, Associate Director of the Chicago Center for Diabetes Translation Research at the University of Chicago, Chicago Illinois, US. “While it does cost additional money, the costs saved by the lower risk of complications offset the upfront costs.”
The lifetime analysis showed that CGM would be expected to extend life expectancy by an average of 0.72 years and reduce the average incidence rates of most major T1D complications. Patients gained 0.54 QALYs and CGM was cost-effective, with an incremental cost-effectiveness ratio (ICER) of USD98,108 per QALY for the overall population.
When CGM use was extended from 7 to 10 days, the annual cost of CGM was reduced to USD3,271. ICER, on the other hand, was decreased to USD33,459 per QALY.
“The CGM looks like a very valuable technology, one that doesn’t cause harm and makes people’s lives better,” Huang said. “It is hoped that CGM will become an important part of the decision-making process for clinicians and their patients with diabetes to make the CGM available to more people.”