Flash CGM Is Associated With Reduced Diabetes Events in T2D

In This Article

Abstract and Introduction

Abstract

Purpose: Suboptimal glycemic control among individuals with diabetes is a leading cause of hospitalizations and emergency department utilization. Use of flash continuous glucose monitoring (flash CGM) improves glycemic control in type 1 and type 2 diabetes, which may result in lower risk for acute and chronic complications that require emergency services and/or hospitalizations.

Methods: In this retrospective, real-world study, we analyzed IBM MarketScan Commercial Claims and Medicare Supplemental databases to assess the impact of flash CGM on diabetes-related events and hospitalizations in a cohort of 2463 individuals with type 2 diabetes who were on short- or rapid-acting insulin therapy. Outcomes were changes in acute diabetes-related events (ADE) and all-cause inpatient hospitalizations (ACH), occurring during the first 6 months after acquiring the flash CGM system compared with event rates during the 6 months prior to system acquisition. ICD-10 codes were used to identify ADE for hypoglycemia, hypoglycemic coma, hyperglycemia, diabetic ketoacidosis, and hyperosmolarity.

Results: ADE rates decreased from 0.180 to 0.072 events/patient-year (hazard ratio [HR]: 0.39 [0.30, 0.51]; P < 0.001) and ACH rates decreased from 0.420 to 0.283 events/patient-year (HR: 0.68 [0.59 0.78]; P < 0.001). ADE reduction occurred regardless of age or gender.

Conclusions: Acquisition of the flash CGM system was associated with reductions in ADE and ACH. These findings provide support for the use of flash CGM in type 2 diabetes patients treated with short- or rapid-acting insulin therapy to improve clinical outcomes and potentially reduce costs.

Introduction

The global prevalence of diabetes is estimated to increase from 9.3% (463 million people) in 2019 to 10.2% (578 million people) by 2030,^[1] with the total cost of care rising to US $2.2 trillion.^[2] Hospitalizations and emergency department utilization are primary contributors to these costs. In a recent American Diabetes Association report, the total direct cost of diabetes was estimated to be US $237.3 billion in 2017.^[3] Approximately 38% of these costs were attributed to hospital inpatient care ($69.7 billion), hospital outpatient treatment ($12.1 billion), emergency department utilization ($8.0 billion) and ambulance services ($332.0 million).

Hospitalizations are prevalent among individuals with type 2 diabetes, who account for 90% to 95% of all diabetes cases.^[4] Adults with type 2 diabetes are admitted for emergency department treatment or hospitalized for numerous health conditions, including severe hyperglycemia and hypoglycaemia.^[5–9] These events are particularly common among patients with large fluctuations in glycated hemoglobin (HbA1c) and very high or very low average HbA1c levels.^[10]

Suboptimal glycemic control using traditional blood glucose monitoring persists among a substantial number of patients with type 2 disease.^[11,12] However, randomized controlled trials have demonstrated that use of continuous glucose monitoring (CGM) significantly lowers HbA1c,^[13] with reductions in hypoglycemia^[14,15] and improved treatment satisfaction^[13,14] in various type 2 diabetes populations.

Unlike traditional self-monitoring of blood glucose (SMBG), CGM systems provide a continuous stream of glucose data, indicating the current interstitial glucose level and the direction and velocity of changing glucose. This information allows users to quickly intervene to prevent or reduce acute hypoglycemia or hyperglycemia.

The FreeStyle Libre 14-day system, manufactured by Abbott Diabetes Care, Alameda, CA, is the only flash CGM system currently available in the US. An earlier version (10-day system) was available from 2017 to 2019. Unlike traditional blood glucose monitors, which provide only a single "point-in-time" glucose value, flash CGM systems utilize a single-use, factory-calibrated sensor that continuously measures interstitial glucose levels. By scanning the sensor with the reader or smartphone, the user can view the current glucose value as well as the glucose pattern over the past 8 hours with trend arrows, which indicate the direction and velocity of changing glucose levels.

Suboptimal glycemic control among individuals with diabetes is a leading cause of hospitalizations and emergency department utilization. Use of flash continuous glucose monitoring (flash CGM) improves glycemic control in type 1 and type 2 diabetes, which may result in lower risk for acute and chronic complications that require emergency services and/or hospitalizations.

We analyzed the effects of system acquisition on inpatient and emergency outpatient acute diabetes-related event (ADE) and all-cause hospitalization (ACH) rates, in a large population of patients with type 2 diabetes who were treated with short- or rapid-acting insulin therapy. This represents the early real-world experience of patients using flash CGM systems.

Table 1. Patient Characteristics
Mean age, years (mean ± SD [10%, 90% deciles])	54.2 ± 9.6 (41, 64)
Male gender, % (n)	52.9% (1304)
Follow-up days [10%, 90% deciles]	173 [163, 182]
Comorbidities, % (n)
Lipid disorder	89.7% (2210)
Hypertension	87.5% (2155)
Obesity	60.0% (1479)
Neuropathy	48.1% (1185)
Retinopathy	31.2% (768)
Depression	29.4% (724)
Pulmonary disease	28.8% (709)
Hypothyroidism	26.2% (646)
Anemia	25.8% (635)
Myocardial infarction or coronary artery disease	24.6% (606)
Liver disease	20.8% (513)
Renal disease	19.5% (480)
Peripheral vascular disease	17.4% (429)
Heart failure	13.1% (323)
Insurance type, % (n)
Commercial insurance	93.5% (2302)
Medicare supplemental insurance	6.5% (161)

Table 2. Number of Events and Number of Patients Affected
Event type	6-months pre-acquisition # events (# affected)	6-months post-acquisition # events (# affected)
All-cause inpatient hospitalizations (ACH)	516 (357)	331 (239)
Acute diabetes events (ADE)^a	221 (181)	84 (73)
Hypoglycemic ADE	24 (21)	17 (16)
Hyperglycemic ADE	199 (166)	69 (62)

Each event type shows number of events (number of patients with event).
^aIn rare cases, when a hypoglycemic and hyperglycemic billing code appear on the same day, a single ADE is counted. So, totals on this row will be slightly lower than the sum of bottom 2 rows.

Table 3. Most Common Causes of All-Cause Hospitalization by Major Diagnostic Category
Before flash CGM		After flash CGM
Hospitalizations (events/100 pt-yr)	Major diagnostic category	Hospitalizations (events/100 pt-yr)	Major diagnostic category
7.8	Circulatory system	6.9	Circulatory system
6.4	Endocrine, nutritional, and metabolic system	2.8	Infectious and parasitic DDs (systemic or unspecified sites)
4.8	Infectious and parasitic DDs (systemic or unspecified sites)	2.8	Musculoskeletal system and connective tissue
3.5	Respiratory system	2.7	Digestive system
3.3	Kidney and urinary tract	2.6	Endocrine, nutritional, and metabolic system
3.2	Musculoskeletal system and connective tissue	2.1	Respiratory system
3.1	Digestive system	1.7	Kidney and urinary tract
2.9	Nervous system	1.6	Nervous system
2.4	Hepatobiliary system and pancreas	1.4	Hepatobiliary system and pancreas

Event rates per 100 patient years in the 6-month period pre-flash CGM acquisition and the 6-month period post-flash CGM acquisition are illustrated for major diagnostic categories. Each side of the table is sorted from highest to lowest event rate.