Table 3.
Safety Outcomes during the 13-Week Trial Period.*
| Event | Closed-Loop Group (N = 68) |
Standard-Care Group (N = 34) |
P Value† |
|---|---|---|---|
| All adverse events | |||
| No. of patients with an event (%) | 41 (60) | 11 (32) | 0.001 |
| No. of events | 71 | 14 | |
| No. of events per 100 person-yr | 413 | 163 | |
| Serious adverse events — no. of patients | |||
| Severe hypoglycemia | 2 | 1 | |
| Diabetic ketoacidosis | 1‡ | 0 | |
| Other serious adverse events§ | 0 | 1 | |
| Nonserious adverse events | |||
| Hyperglycemia with or without ketosis, related to trial device¶ | |||
| No. of patients with an event (%) | 26 (38) | NA | |
| No. of events | 39 | ||
| Hyperglycemia with or without ketosis, not related to trial device | |||
| No. of patients with an event (%) | 9 (13) | 7 (21) | |
| No. of events | 12 | 8 | |
| Other reportable adverse events∥ | |||
| No. of patients with an event (%) | 15 (22) | 3 (9) | |
| No. of events | 17 | 4 | |
| Other safety outcomes | |||
| Increase in glycated hemoglobin level by >0.5 percentage points from baseline to 13 wk — no. of patients (%)** | 1 (2) | 0 | |
| Days with ≥1 blood ketone meter measurement >1.0 mmol/liter — no./total person-days of follow-up (%) | 27/6350 (0.43) | 7/3165 (0.22) | 0.14 |
Reportable adverse events included serious adverse events, adverse events that occurred in association with a trial device or procedure, severe hypoglycemia with altered consciousness that required the assistance of a third party for treatment, diabetic ketoacidosis as defined in the Diabetes Control and Complications Trial,10 acute cases of hyperglycemia or ketosis for which a health care provider was contacted, and a blood ketone level of at least 1.0 mmol per liter, even if there was no communication with a health care provider at the time of the event. NA denotes not applicable.
P values were calculated only for the outcomes that were prespecified in the statistical analysis plan.
This case of diabetic ketoacidosis was related to an infusion-set failure.
One patient in the standard-care group was hospitalized for an asthma flare.
The trial device included the insulin pump, infusion set, and continuous glucose monitor. Most cases of hyperglycemia that were considered by the medical monitor to be related to the trial device were due to infusion-set failures.
In the closed-loop group, other reportable adverse events (in 17 patients) were the following: bleeding at the pump infusion site (in 1 patient), burn (in 1 patient), coronavirus disease 2019 (in 3 patients), gastroenteritis (in 2 patients), hematuria (in 1 patient), hypoglycemia (in 2 patients), infection at the pump infusion site (in 2 patients), infection at the sensor infusion site (in 1 patient), injury from a fall (in 2 patients), streptococcus pharyngitis (in 1 patient), and upper respiratory infection (in 1 patient); in the standard-care group, an adverse event in this category was gastroenteritis (in 4 patients).
Data regarding an increase in the glycated hemoglobin level were available for 59 patients in the closed-loop group and for 31 patients in the standard-care group.