Table 1—

Differences in glucose values (mg/dl) from CGM in reference to YSI and SMBG

No. of paired data pointsAbsolute difference (mg/dl)*
Relative difference (%)
Absolute relative difference (%)*
Mean ± SDMedianMean ± SDMedianMean ± SDMedian
YSI in-clinic days 2, 7, and 10§5.0 ± 27.31.4
    Overall90525.2 ± 25.417.317.9 ± 21.212.9
    Day−0.1 ± 18.3−1.2
        227123.6 ± 21.116.54.5 ± 20.51.714.4 ± 11.312.6
        722721.2 ± 21.016.08.7 ± 34.31.615.7 ± 14.011.3
        1040728.4 ± 29.718.85.0 ± 27.31.421.6 ± 27.914.5
        P0.080.020.63
SMBG in-clinic days 2, 7, and 10
    Overall1,130−0.9 ± 26.3−4.917.7 ± 19.513.3
    Day24.8 ± 25.317.0
        237923.0 ± 22.516.00.2 ± 21.4−1.915.6 ± 14.512.8
        731720.9 ± 25.115.5−2.7 ± 21.3−6.415.7 ± 14.612.5
        1043420.9 ± 25.115.5
        P0.030.0020.002
  • Data are mean ± SD or median unless otherwise indicated.

  • *

    * Calculated as absolute value of (sensor − YSI) where, for each paired point, sensor = time-matched continuously measured glucose value and YSI = SMBG values.

  • Calculated as (sensor − YSI)/YSI.

  • ‡Calculated as the absolute value of (sensor − YSI)/YSI.

  • From the time of sensor insertion (in 24-h increments). P values calculated by the χ2 Kruskal-Wallis test from median values.

  • §

    § Percent of points within 20% of reference = 70.8%; percent of points within 30% of reference = 87.6%.

  • Percent of points within 20% of reference = 73.4%; percent of points within 30% of reference = 88.7%.