Table 2

Within-trial cost-effectiveness results

Control (n = 53)CGM (n = 103)
Mean (SD)Median (range or IQR)Mean (SD)Median (range or IQR)
Utility and QALYsP valueb
 Utility change from baseline0.0 (0.08)0 (−0.27, 0.26)−0.01 (0.09)0 (−0.33, 0.32)0.78
 QALYs0.46 (0.06)0.47 (0.13, 0.50)0.46 (0.05)0.47 (0.24, 0.50)0.61
Costs, $P valueb
 Total direct costs3,118 (3,120)2,565 (1,928, 3,277)5,336 (3,070)5,092 (4,485, 5,726)<0.01
  Direct trial personnel96 (205)47 (0, 94)60 (77)47 (0, 94)0.41
  Medical care3,022 (3,088)2,478 (1,880, 3,122)2,921 (3,065)2,509 (1,909, 3,095)0.86
  CGM0 (0)02,554 (0)2,554<0.01
 Total indirect costsa36 (121)0 (0, 0)54 (314)0 (0, 0)0.85
  Missed work26 (101)0 (0, 0)36 (307)0 (0, 0)0.65
  Poor performance10 (40)0 (0, 0)18 (70)0 (0, 0)0.63
  Self-management4,012 (5,529)2,829 (0, 5,610)5,473 (10,300)2,829 (2,259, 5,658)0.86
 Total costs7,236 (6,097)5,287 (4,586, 8,223)11,200 (11,300)8,178 (6,864, 10,300)<0.01
 Total costsa3,154 (3,122)2,565 (1,999, 3,513)5,593 (3,083)5,105 (4,496, 5,780)<0.01
Clinical outcomes: reduction from baselineP valueb
  HbA1c−0.39 (0.70)−0.30 (−3.20, 0.90)−0.99 (0.77)−1.00 (−3.00, 0.70)<0.01
  Daily strip tests0.1 (1.5)0 (−4, 3)−0.5 (1.5)0 (−5, 3)0.04
  Insulin dose1.0 (11)1 (−23, 25)−2.3 (22)0 (−145, 52)0.31
  Daily rate of NSHEs−0.06 (0.27)0 (−0.93, 0.47)−0.12 (0.29)−0.08 (−1.07, 0.63)0.02c
  BMI0.27 (1.07)0.15 (−2.22, 2.80)0.59 (1.38)0.56 (−3.42, 5.28)0.16
  Patients having severe hyperglycemic events, n (%)1 (2)0 (0)0.34
  Patients having severe hypoglycemic events, n (%)2 (4)2 (2)0.6
Subgroup analyses: reduction from baselineP valuec
 In the subgroup with high baseline HbA1c (≥8.5%)
  HbA1c−0.53 (0.60)−0.50 (−1.5, 0.8)−1.29 (0.77)−1.30 (−3, 0.3)0.02
  Daily rate of NSHEs−0.10 (0.29)−0.07 (−0.93, 0.47)−0.08 (0.27)−0.07 (−1.03, 0.63)0.27
 In the subgroup with low baseline HbA1c (<8.5%)
  HbA1c−0.22 (0.78)−0.10 (−3.20, 0.90)−0.63 (0.59)−0.60 (−1.80, 0.70)0.01
  Daily rate of NSHEs−0.02 (0.25)0.01 (−0.86, 0.32)−0.17 (0.32)−0.14 (−1.07, 0.44)0.03
  • All costs data were summarized by interquartile range (IQR) and other continuous outcomes were summarized by range.

  • Bold P values indicate statistical significance (P < 0.05).

  • aBoth total indirect costs and total costs did not include the costs from diabetes self-management due to its 20% missing data and huge variability; that is, ∼20% patients reported unknown daily number of hours of self-management and seven patients from both groups reported ≥12 h/day and two of CGM users reported 24 h/day.

  • bP value was from the Wilcoxon rank sum test to compare the two groups.

  • cP value was from an ANCOVA model adjusting for its baseline outcome and site as a random effect.