JMIR Publications

ABSTRACT

Background:

The impact of missing data on individual continuous glucose monitoring (CGM) data is unknown but can influence clinical decision making for patients.

Objective:

Therefore, we aimed to investigate the consequences of data loss on glucose metrics in individual patient recordings of continuous glucose monitors and its effect on clinical decision making.

Methods:

CGM data were collected from patients with type 1 and 2 diabetes using the FreeStyle Libre sensor. We selected 7–28 day periods of 24-hour of continuous data without any missing values from each individual patient. To mimic real-world data loss, missing data ranging from 5–50% was introduced into the dataset. From this modified dataset the clinical metrics time below range (TBR), time below range level 2 (TBR2) and other common glucose metrics were calculated in the data sets without and with data loss. Recordings in which glucose metrics deviated relevantly due to data loss, as determined by clinical experts, were defined as expert panel boundary errors (εEPB). These errors were expressed as a percentage of the total number of recordings.

Results:

A total of 84 patients contributed to 798 recordings over 28 days. With 5–50% data loss for 7–28 days recordings the εEPB varied from 0.0% to 20.0% for TBR and 0.0% to5.4% recordings for TBR2. In the case of 14-day recordings, TBR and TBR2 episodes completely disappeared due to 30% data loss in 0.3% and 6.1% of the cases, respectively. However, the initial values of the disappeared TBR and TBR2 were relatively small (< 0.15%).

Conclusions:

To ensure that missing data has no more than a 5% impact on all glucose metrics, we recommend having a 14-day CGM recording with a maximum of 30% data loss. Clinical Trial: NCT05584293