We separately analyzed paired FGM and SMBG values obtained during the regular
pre-prandial and nighttime measurements, the pre- and postprandial measurements
from the second and third day of the study, and measurements obtained on
dialysis and non-dialysis days. All participants with at least 50%
paired measurements available over a period of at least 7 days were included in
the primary analysis. Participants with fewer paired measurements during a
shorter period of time or with unreliable data due to non-compliance, acute
illness, or prolonged use of paracetamol were excluded. We used Bland-Altman
plots and paired t-tests to compare the difference between paired glucose values
measured by SMBG vs. FGM. We further calculated the mean absolute difference
(MAD) and the mean absolute relative difference (MARD) for each patient, for all
measurements, and for subgroups of patients or measurement values, as defined.
For the comparison of mean difference, MAD and MARD between dialysis vs.
interdialytic days, between the first 5 days vs. the remainder of the study
period, and between pre- vs. postprandial values, we used a t-test, and for the
comparison between patients with vs. without diabetes and patients with high vs.
low ultrafiltration volume, we used a nested t-test. Agreement between FGM and
SMBG readings was further analyzed using the Surveillance error grid
22 (link)
, available at
Statistical analyses were performed using Microsoft Excel version 2013 and R
software, version 4.0.2 (R Core Team 2020. R: A language and environment for
statistical computing. R Foundation for Statistical Computing, Vienna, Austria.
URL
