Abstract
Regular use of continuous glucose monitoring (CGM) in type 1 diabetes management increases the achievement of glycemic targets and reduces health care utilization, specifically emergency department (ED) visits. This retrospective chart review examined the effects of CGM use in patients with type 1 diabetes in a pediatric ED. Use of CGM was associated with several differences in patient management in the ED. This work is a first step toward development of guidelines for the appropriate use of CGM in the pediatric ED. In the future, CGM use in type 1 diabetes may lead to reduced ED-specific health care costs.
Type 1 diabetes is caused by autoimmune-mediated destruction of insulin-producing pancreatic β-cells. Commonly diagnosed in childhood or early adolescence, the worldwide incidence of type 1 diabetes is increasing (1). Complications of type 1 diabetes include atherosclerosis, neuropathy, and retinopathy, as well as severe hypoglycemia (SH) and diabetic ketoacidosis (DKA). Treatment consists of lowering blood glucose with insulin.
The majority of children with type 1 diabetes are diagnosed in the emergency department (ED) (2). Among children up to 18 years of age, there were ∼109,700 ED visits for all types of diabetes in 2012 (2,3).
Continuous glucose monitoring (CGM) assists in the management of type 1 diabetes and has been shown to reduce A1C regardless of insulin delivery method (4–6). CGM use also reduces health care utilization—specifically ED visits—and decreases the incidence of DKA and SH (7,8). Utilization of CGM has the potential to improve diabetes care for patients in the ED. Individuals with type 1 diabetes treated in the ED require frequent glucose monitoring and expeditious interventions. For example, patients with DKA should have their blood glucose measured at least hourly while receiving intravenous (IV) insulin administration (9). However, there is no research examining how the use of CGM affects care in the ED.
CGM systems that have been confirmed to be working correctly may be used in the ED to 1) identify imminent hypoglycemia, 2) recognize hyperglycemia requiring treatment, and 3) allow for less frequent blood glucose testing. This study aimed to assess the type and timing of care in the ED for individuals with and without CGM to improve type 1 diabetes care in all health care facilities.
Research Design and Methods
This retrospective cohort study examined patients presenting to the University of Florida (UF) Health Pediatric ED from October 2017 through December 2019. It was approved as exempt by the UF IRB-01 (IRB202000656).
The UF Integrated Data Repository provided all eligible ED encounters between 2017 and 2019 with any type 1 diabetes–related International Classification of Diseases, 10th revision (ICD-10), diagnosis codes, yielding 835 encounters. Chart review of eligible encounters was conducted by a single coder over a 3-month period. Electronic health records (EHRs) were reviewed in reverse chronological order, yielding a sufficient sample of 321 encounters spanning the time window of October 2017 through December 2019. Each encounter was evaluated for accuracy of the type 1 diabetes diagnosis (46 encounters excluded) and completion of a patient workup in the ED (four encounters excluded).
Patient demographics, insurance type, and diabetes history were extracted from the EHR, including CGM use at the time of the encounter or the most recent diabetes clinic visit. Additional encounter-specific information included 1) the number and timing of point-of-care (POC) and laboratory tests, 2) the type and timing of insulin and IV fluids, 3) patient disposition, and 4) A1C at the ED encounter. Encounters were grouped by whether or not the chief concern (CC) was related to blood glucose.
Data were collected and managed using a REDCap (Research Electronic Data Capture) database hosted by UF (10,11). REDCap is a secure, Web-based software platform providing 1) an intuitive interface for validated data capture, 2) audit trails for tracking data manipulation and export procedures, 3) automated export procedures for data downloads to common statistical packages, and 4) procedures for data integration and interoperability with external sources.
Descriptive statistics including demographics, diabetes-related insulin therapy, and technology use, reported as frequencies and percentages or medians and interquartile ranges (IQRs), were calculated and stratified by CC and CGM use; ED encounter was the unit of analysis. Statistical comparisons of encounter characteristics and time in the ED were evaluated and stratified by CC and CGM use. Categorical and continuous variables were compared using χ2 and Mann-Whitney U tests, respectively. A predetermined α level of 0.05 was used to evaluate statistical significance. Data management and analysis were conducted using SAS, v. 9.4, statistical software (SAS Institute, Cary, NC).
Results
A total of 271 ED visits were included in the analysis (Figure 1). The median age was 14.0 years (IQR 10.0–16.0 years). Forty-eight percent of encounters included patients using CGM. In our cohort, CGM users were younger (P <0.0001) with a shorter diabetes duration (P = 0.0101) than individuals not using CGM (Table 1). There were differences in CGM use by race (P = 0.0017), insurance type (P = 0.0060), and concurrent insulin pump use (P <0.0001). Encounters with a CC related to blood glucose (n = 124) and those unrelated to blood glucose (n = 147) were analyzed separately, including assessment of laboratory tests ordered and IV fluid and insulin administered (Tables 2 and 3).
FIGURE 1.
Selection process for encounters included in the analysis.
Table 1.
Patient Demographics Stratified by CGM Use
| Overall | No CGM Use | CGM Use | P | |
|---|---|---|---|---|
| (n = 271 [100%]) | (n = 141 [52.0%]) | (n = 130 [48.0%]) | ||
| Male sex | 118 (43.5) | 69 (48.9) | 49 (37.7) | 0.0622 |
| Age, years | 14.0 (10.0–16.0) | 15.0 (12.0–17.0) | 12.0 (9.0–15.0) | <0.0001 |
| Diabetes duration, years | 4.8 (2.1–8.3) | 6.2 (2.7–8.9) | 3.9 (1.4–7.8) | 0.0101 |
| Race/ethnicity | 0.0017 | |||
| Hispanic Non-Hispanic Black Non-Hispanic White Non-Hispanic multiracial Non-Hispanic other |
29 (10.7) 35 (12.9) 192 (70.9) 7 (2.6) 8 (3.0) |
11 (7.8) 25 (17.7) 100 (70.9) 5 (3.6) 0 (0) |
18 (13.9) 10 (7.7) 92 (70.8) 2 (1.5) 8 (6.2) |
|
| Insurance | 0.0060 | |||
| Commercial Public Self-pay |
85 (31.4) 181 (66.8) 5 (1.9) |
32 (22.7) 106 (75.2) 3 (2.1) |
53 (40.8) 75 (57.7) 2 (1.5) |
|
| CC | 0.2593 | |||
| Blood glucose–related Abdominal pain Vomiting Other |
124 (45.8) 24 (8.9) 28 (10.3) 95 (35.1) |
72 (51.1) 10 (7.1) 12 (8.5) 47 (33.3) |
52 (40.0)
14 (10.8) 16 (12.3) 48 (36.9) |
|
| Insulin therapy* | <0.0001 | |||
| Injections | 179 (66.3) | 116 (82.9) | 63 (48.5) | |
| Pump | 91 (33.7) | 24 (17.1) | 67 (51.5) | |
Data are n (%) or median (IQR). Statistical testing: Cochran-Mantel-Haenszel general association for multilevel categorical data; χ2 for 2 × 2 categorical data; t tests for continuous data. Bold type indicates statistical significance.
Total n = 270; data missing for one nonuser of CGM.
TABLE 2.
Patient Demographics Stratified by CC Related or Not Related to Blood Glucose and CGM Use
| Overall (n = 271 [100%]) | CC Related to Blood Glucose | CC Not Related to Blood Glucose | |||
|---|---|---|---|---|---|
| No CGM Use (n = 72 [58.1%]) | CGM Use (n = 52 [41.9%]) | No CGM Use (n = 69 [46.9%]) | CGM Use (n = 78 [53.1%]) | ||
| Male sex | 118 (43.5) | 32 (44.4) | 19 (36.5) | 37 (53.6) | 30 (38.5) |
| Age, years | 14.0 (10.0–16.0) | 15.0 (13.0–17.0) | 12.0 (9.0–15.0) | 15.0 (11.0–17.0) | 12.0 (8.0–15.0) |
| Diabetes duration, years | 4.8 (2.1–8.3) | 6.9 (2.9–9.3) | 3.9 (1.9–7.9) | 5.6 (2.6–7.8) | 3.5 (1.3–7.8) |
| Race/ethnicity | |||||
| Hispanic Non-Hispanic Black Non-Hispanic White Non-Hispanic multiracial Non-Hispanic other |
29 (10.7) 35 (12.9) 192 (70.9) 7 (2.6) 8 (3.0) |
5 (6.9) 13 (18.1) 52 (72.2) 2 (2.8) 0 (0) |
4 (7.7) 5 (9.6) 40 (76.9) 1 (1.9) 2 (3.9) |
6 (8.7) 12 (17.4) 48 (69.6) 3 (4.4) 0 (0) |
14 (18.0) 5 (6.4) 52 (66.7) 1 (1.3) 6 (7.7) |
| Insurance | |||||
| Commercial Public Self-pay |
85 (31.4) 181 (66.8) 5 (1.9) |
13 (18.1) 56 (77.8) 3 (4.1) |
16 (30.8) 35 (67.3) 1 (1.9) |
19 (27.5) 50 (72.5) 0 (0) |
37 (47.4) 40 (51.3) 1 (1.3) |
| CC | |||||
| Blood glucose–related Abdominal pain Vomiting Other |
124 (45.8) 24 (8.9) 28 (10.3) 95 (35.1) |
72 (100.0) 0 (0) 0 (0) 0 (0) |
52 (100.0) 0 (0) 0 (0) 0 (0) |
0 (0) 10 (14.5) 12 (17.4) 47 (68.1) |
0 (0) 14 (18.0) 16 (20.5) 48 (61.5) |
| Insulin therapy* | |||||
| Injections Pump |
179 (66.3) 91 (33.7) |
57 (79.2) 15 (20.8) |
26 (50.0) 26 (50.0) |
59 (86.8) 9 (13.2) |
37 (47.4) 41 (52.6) |
| CGM system | |||||
| Dexcom G5 Dexcom G6 MiniMed Enlite MiniMed Guardian 3 FreeStyle Libre 14-day |
46 (35.4) 71 (54.6) 1 (0.8) 3 (2.3) 9 (6.9) |
— — — — — |
22 (42.3) 27 (51.9) 0 (0) 1 (1.9) 2 (3.9) |
— — — — — |
24 (30.8) 44 (56.4) 1 (1.3) 2 (2.6) 7 (9.0) |
Data are n (%) or median (IQR).
Total n = 270; data missing for one visit not related to blood glucose with no CGM use.
Table 3.
Encounter Descriptives Stratified by CC Related or Not Related to Blood Glucose and CGM Use
| Overall (n = 271) | CC Related to Blood Glucose | CC Not Related to Blood Glucose | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No CGM Use (n = 72 [58.1%]) | CGM Use (n = 52 [41.9%]) | P | No CGM Use (n = 69 [46.9%]) | CGM Use (n = 78 [53.1%]) | P | |||||||
| Ordered: | ||||||||||||
| BMP/CMP POC urine ketones POC blood ketones β-Hydroxybutyrate Urinalysis POC blood gas A1C A1C result, % A1C result, mmol/mol POC glucose test ordered while in ED POC glucose tests per patient |
208 (76.8) 158 (58.3) 24 (8.9) 33 (12.2) 40 (14.8) 178 (65.7) 107 (39.5) 11.3 (8.8–12.5) 100 (73–113) 211 (77.9) 2.0 (1.0–3.0) |
66 (91.7) 54 (75.0) 5 (6.9) 16 (22.2) 15 (20.8) 64 (88.9) 45 (62.5) 11.8 (11.2–13.1) 105 (99–120) 62 (86.1) 2.0 (2.0–4.0) |
47 (90.4) 33 (63.5) 6 (11.5) 4 (7.7) 6 (11.5) 43 (82.7) 28 (53.9) 9.8 (8.6–11.8) 84 (70–103) 48 (92.3) 2.0 (1.0–2.5) |
0.8043 0.1658 0.3746 0.0299 0.1733 0.3222 0.3339 0.0005 0.0005 0.2820 0.0466 |
51 (73.9) 39 (56.5) 5 (7.3) 5 (7.3) 8 (11.6) 34 (49.3) 18 (26.1) 11.9 (10.3–12.8) 107 (89–116) 57 (82.6) 2.0 (1.0–2.0) |
44 (56.4) 32 (41.0) 8 (10.26) 8 (10.3) 11 (14.1) 37 (47.4) 16 (20.5) 7.4 (7.0–7.8) 57 (53–62) 44 (56.4) 2.0 (1.0–2.0) |
0.0268 0.0606 0.5212 0.5212 0.6510 0.8237 0.4238 <0.0001 <0.0001 0.0006 0.3861 |
|||||
| Administered: | ||||||||||||
| Insulin IV fluids Type: normal saline bolus |
127 (46.9) 192 (70.9) 159 (82.8) |
50 (69.4) 63 (87.5) 53 (73.6) |
31 (59.6) 42 (80.8) 36 (69.2) |
0.2565 0.3045 0.5928 |
30 (43.5) 45 (65.2) 37 (53.6) |
16 (20.5) 42 (53.9) 33 (42.3) |
0.0027 0.1615 0.1704 |
|||||
| ED treatment | ||||||||||||
| Patients admitted | 123 (45.4) | 46 (63.9) | 24 (46.2) | 0.0494 | 25 (36.2) | 28 (35.9) | 0.9664 | |||||
| Time to admission orders* | 100.0 (71.0–165.0) | 85.0 (52.0–142.0) | 84.5 (65.5–119.0) | 0.8576 | 128.0 (84.0–165.0) | 145.0 (101.5–255.0) | 0.1011 | |||||
| Time to hospital room* | 201.0 (139.0–293.0) | 176.0 (127.0–230.0) | 171.0 (133.5–246.0) | 0.7618 | 236.0 (166.0–290.0) | 284.5 (204.5–365.5) | 0.2058 | |||||
| Patients discharged | 148 (54.6) | 26 (36.1) | 28 (53.9) | 0.0494 | 44 (63.8) | 50 (64.1) | 0.9664 | |||||
| Time to discharge* | 214.0 (158.0–275.0) | 235.0 (163.0–326.0) | 216.0 (159.5–256.5) | 0.3153 | 207.5 (161.0–266.5) | 204.5 (141.0–289.0) | 0.8143 | |||||
| Overall | No CGM Use | CGM Use | P | No CGM Use | CGM Use | P | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | Median (IQR) | n | Median (IQR) | n | Median (IQR) | n | Median (IQR) | n | Median (IQR) | |||
| For tests ordered: | ||||||||||||
| Time to first POC glucose test* Time to first POC glucose test* Time to urine ketones test* Time to POC blood gas test* |
211 208 158 178 |
29.0 (13.0–77.0) 41.0 (25.0–66.0) 87.0 (53.0–128.0) 41.0 (25.0–61.0) |
62 66 54 64 |
18.5 (11.0–67.0) 30.5 (21.0–48.0) 71.0 (48.0–110.0) 31.0 (23.0–53.5) |
48 47 33 43 |
24.5 (10.5–70.5) 40.0 (25.0–69.0) 104.0 (61.0–133.0) 41.0 (25.0–70.0) |
0.8754 0.0394 0.0182 0.0736 |
57 51 39 34 |
36.0 (17.0–86.0) 50.0 (33.0–103.0) 88.0 (53.0–131.0) 48.5 (30.0–86.0) |
44 44 32 37 |
46.0 (17.0–100.5) 47.5 (32.0–69.0) 103.0 (70.0–142.0) 47.0 (32.0–64.0) |
0.5064 0.2709 0.4086 0.7691 |
| When administered: | ||||||||||||
| Time to IV fluids* Time to first dose of insulin* |
192 124 |
54.5 (36.5–84.0) 120.5 (81.5–177.0) |
63 49 |
44.0 (27.0–61.0) 120.0 (68.0–147.0) |
42 30 |
52.5 (39.0–76.0) 94.5 (71.0–129.0) |
0.0730 0.2140 |
45 29 |
76.0 (43.0–113.0) 136.0 (105.0–191.0) |
42 16 |
64.5 (42.0–110.0) 156.0 (115.0–235.0) |
0.4242 0.4339 |
Data are n (%) analyzed by χ2 test or median (IQR) analyzed by Mann-Whitney U test unless otherwise indicated. Bold type indicates statistical significance (α = 0.05).
All times are reported in minutes.
Frequency and Timing of Laboratory Studies
There was no difference in the rate of CGM use between people whose CC was or was not related to blood glucose (41.9 and 53.1%, respectively; P = 0.0678). Among those with blood glucose–related CCs, the most common were hyperglycemia and hypoglycemia. Individuals using CGM were less likely to have a β-hydroxybutyrate level ordered (7.7 vs. 22.2%, P = 0.0299) and had a lower median A1C (9.8 vs. 11.8% [84 vs. 105 mmol/mol], P = 0.0005). There was no difference based on CGM use in the percentage of patients who had a POC glucose test ordered; however, when POC glucose tests were ordered, those who did not use CGM had a higher number of tests (P = 0.0466). The timing of certain laboratory studies for nonusers of CGM appeared expedited compared with CGM users (time to a basic or complete metabolic panel [BMP/CMP] 30.5 vs. 40.0 minutes, P = 0.0394; time to a urine ketone test 71.0 vs. 104.0 minutes, P = 0.0182).
The most frequent CCs that were not related to blood glucose were abdominal pain and vomiting. Fewer CGM users had BMP/CMP tests (56.4 vs. 73.9%, P = 0.0268), and CGM users were less likely to have a POC blood glucose measurement (56.4 vs. 82.6%, P = 0.0006), although the number of tests per patient and the timing of these studies were not different in those for whom they were ordered. Median A1C was lower among CGM users (7.4 vs. 11.9% [57 vs. 107 mmol/mol], P <0.0001).
Timing of Insulin/IV Fluid Therapy and Rate of Hospitalization
There were no differences in the timing of IV fluids or the time to first insulin dose administration based on CGM usage regardless of whether the CC was related to blood glucose (Table 3). For CCs that were not related to blood glucose, insulin was ordered less frequently for CGM users than for nonusers (20.5 vs. 43.5%, P = 0.0027); insulin administered by ED staff and patients’ self-administered personal insulin from home were both included in this analysis. CGM use did not affect the frequency of insulin administration for those with a blood glucose–related CC.
There were no CGM-based between-group differences in time to discharge or time to hospital room for those admitted, regardless of CC (Table 3). CGM users were admitted at a lower rate than nonusers for blood glucose–related CCs (46.2 vs. 63.9%, P = 0.0494); however, there was no difference in admission rates for CCs that were not related to blood glucose (35.9 and 36.2% for CGM users and nonusers, respectively; P = 0.9664).
Discussion
Of the individuals with type 1 diabetes included in this study, CGM users in the pediatric ED had fewer laboratory tests with a longer latency period than nonusers of CGM. For CCs that were related to blood glucose, CGM users were hospitalized at a lower rate than nonusers. CGM users may have appeared less ill, or their symptoms may have been caught sooner because of their CGM use, which could have affected (i.e., reduced the sense of urgency around) the number and timing of laboratory tests.
As previously reported, CGM use results in lower A1C (5,7). Even for patients with CCs that were not related to blood glucose, CGM use was associated with variations in ED care. CGM users required less insulin and fewer POC glucose tests while in the ED. We can speculate that, compared with CGM users, nonusers have more limited knowledge of their blood glucose levels or trends and may require urgent insulin management despite having a CC unrelated to diabetes.
Results of this study are limited in part because of variable documentation across ED visits, including discrepancies in nursing notes and laboratory versus POC test results, as well as CGM usage before, during, and after ED encounters. Some patients were using CGM before their ED visit but were not wearing a sensor at the ED. In addition, patient acuity and ED capacity are not considered in this analysis. Despite these limitations, this information may lead to improved ED care for patients with type 1 diabetes.
We found that there were diagnostic and treatment differences between CGM users and nonusers in the ED. Our work provides a foundation for future retrospective and prospective studies of the use of CGM in the ED. This analysis is an early step toward developing consensus guidelines among pediatric generalists, endocrinologists, and emergency medicine providers regarding the use of CGM and interpretation of the data it provides. Ideally, the numerous benefits of CGM in the management of type 1 diabetes can be extended to ED visits with the potential added benefit of reducing ED-specific health care costs.
Article Information
Duality of Interest
No potential conflicts of interest relevant to this article were reported.
Author Contributions
R.K.B. designed the research study, collected chart review data, and wrote the manuscript. S.L.F. designed the research study, analyzed the data, and contributed to the Research Design and Methods section. L.M.J. designed the research study and wrote the manuscript. L.M.J. is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
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