Table 3

Study outcomes

CGM-only groupCGM+BGM group
CGM resultsBaseline(n = 149)26-week study period (n = 148)*Baseline(n = 77)26-week study period (n = 76)*P value
Hours of CGM data 640 (620–650)4,007 (3,709–4,166)641 (619–651)4,021 (3,725–4,136)
 Range306–663467–4,399270–684811–4,535
% Time in range (70–180 mg/dL)63 ± 1363 ± 1365 ± 1365 ± 110.81
Mean glucose (mg/dL)162 ± 22162 ± 23158 ± 22158 ± 20>0.99
Coefficient of variation (%)36 (33–41)37 (34–41)37 (33–40)37 (34–40)0.58
Hypoglycemia
 % Time <70 mg/dL2.9 (1.5–4.5)3.0 (1.6–5.1)3.6 (1.9–4.8)3.7 (1.9–4.9)0.95
 % Time <60 mg/dL1.1 (0.6–1.9)1.3 (0.5–2.4)1.4 (0.6–2.3)1.6 (0.6–2.2)0.57
 % Time <50 mg/dL0.3 (0.1–0.6)0.4 (0.2–0.8)0.4 (0.2–0.7)0.5 (0.2–0.8)0.75
 Area above curve 70 mg/dL0.3 (0.2–0.5)0.3 (0.1–0.6)0.4 (0.2–0.6)0.4 (0.2–0.5)0.76
% Days with ≥20 consecutive min glucose values <60 mg/dL25 (15–43)28 (13–42)33 (15–43)32 (16–46)0.68
Hyperglycemia
    % Time >180 mg/dL33 (25–43)35 (25–41)31 (22–40)31 (24–38)0.88
    % Time >250 mg/dL8 (4–15)9 (5–13)7 (3–11)7 (4–11)0.65
    % Time >300 mg/dL2 (1–5)2 (1–4)2 (1–4)2 (1–3)0.72
    Area under curve 180 mg/dL17 (10–25)17 (10–23)14 (8–22)15 (9–21)0.90
% Days with ≥20 consecutive min of glucose values >300 mg/dL25 (12–48)27 (14–40)20 (8–36)20 (10–37)0.72
HbA1c resultsBaseline (n = 149)Week 26 visit (n = 142)Baseline (n = 77)Week 26 visit (n = 75)P value
HbA1c
 %7.1 ± 0.77.1 ± 0.77.0 ± 0.77.0 ± 0.6
 mmol/mol54 ± 7.754 ± 7.753 ± 7.753 ± 6.6
Change in HbA1c from baseline 0.41
 %0.0 ± 0.50.0 ± 0.5
 mmol/mol0.0 ± 5.50.0 ± 5.5
No worsening of HbA1c by >0.3% (3.3 mmol/mol) and no severe hypoglycemic event115 (81)54 (72)0.15
  • Data are median (interquartile range), mean ± SD, or n (%) unless otherwise indicated.

  • *One participant in the CGM-only group and one in the CGM+BGM group never came in for a follow-up visit and therefore had no CGM data;

  • †two-sided P value for the CGM metrics and change in HbA1c are from ANCOVA models adjusted for the corresponding baseline value and site as a random effect. Because of the skewed distributions for the CGM coefficient of variation, as well as the CGM hypoglycemia and hyperglycemia metrics, these models were based on van der Waerden score rankings. The P value for the HbA1c/severe hypoglycemia combined outcome is from a logistic regression model adjusted for baseline HbA1c and site as a random effect. Results were similar for the % time in range when also adjusting for education;

  • ‡1% time equals 14.4 min/day.