Introducing the Continuous Glucose Data Analysis (CGDA) R Package: An Intuitive Package to Analyze Continuous Glucose Monitoring Data.

Abstract

The first continuous glucose monitors (CGM) have been introduced more than 20 years ago and today multiple options exist.1 These options consist of real-time CGM (rtCGM) and intermittent CGM (iCGM) or Flash monitors. The rt-CGM measure the glucose levels continuously and can alert if a patient is moving toward a hypoor a hyperglycaemic event. The iCGM, however, only show the glucose levels when the patient actively scans the device. Multiple studies have shown that implementing CGM in routine clinical care has positive effects, regardless of the type of CGM.2 The main benefit is that CGM show real-time glucose levels and fluctuation, thereby overcoming limitations of “old” metrics such as HbA1c and fasting glucose levels. However, despite recommendations, routine use of CGM in clinical practice remains scare.3 A possible explanation for this is the fact that using and interpreting results from CGM remains difficult for health care practitioners. Furthermore, analyses of the data in clinical trials differ widely and are therefore difficult to generalize and use in clinical practice.2 Recently, the American Diabetes Association (ADA) published a guideline on how to use CGM in daily practice.3 To date, no tool exists that can easily and intuitively provide these data from CGM. Several statistical packages do exist that can assist in extracting data from the CGM (e.g., HbA1c, glycemic excursions).4,5 However, a major drawback of these packages is that the user needs to be familiar with programming and the output is often in mg/dL or %, making implementation and interpretation for clinicians that use other metrics difficult. Moreover, analyses packages of manufacturers are not insightful in how analyses are done and which algorithms are used. Through this letter we wish to introduce the Continuous Glucose Data Analysis (CGDA) Package in the programming language R. This is an easy-to-use, free package that incorporates the ADA recommendations, has graphical output, and provides output in all commonly used metrics (i.e., glucose mmol/mol, mg/dL, and HbA1c % as well as mg/dL).