Page 54 - Glucose Monitoring Devices

52 CHAPTER 4 Consequences of SMBG systems inaccuracy

This work focuses on understanding how the accuracy characteristics of these
technologies contribute to the quality of glycemic control.
This chapter surveys current efforts to characterize hypothesized relationships
(illustrated in Fig. 4.1) between accuracy and outcomes. As shown in the figure,
these range from the clinical to the financial, from the immediate to the long
term. The approaches discussed here cover vastly different methodologies from
direct clinical observations and surveys, to modeling and simulation-based studies,
to meta-analysis. In the end, and despite their methodological differences, these
studies deliver a clear and consistent message. Inaccurate BGM systems can nega-
tively affect the patient’s glycemic control, quality of life, and finances. Continued
use of inaccurate BGM systems may result in an increased prevalence of long-term
health complications affecting both the patient’s quality of life and the financial
health of families. When we switch our focus from an individual to the entire
population, these effects aggregate over time to affect worker productivity and
healthcare costs.
The chapter is organized as follows. In the first section, we set up the problem of
characterizing the effect of accuracy. This requires defining how we measure the
inputs (accuracy) and the outputs (clinical, quality of life, financial cost). We discuss
the nuances and complexities involved that make this an interesting problem. In Sec-
tion Quantifying the effect of inaccurate BGM systems, we introduce an approach to
the problem based on modeling and simulation, in which we decompose the overall
problem into more manageable steps. Finally, in Section Accuracy and its conse-
quences, we present an extended illustration of our approach. The example describes
how modeling and simulation can be used to estimate the effects of SMBG accuracy
on patients using multiple daily injections (MDI) both in terms of short-term clinical
and cost metrics and long-term clinical complications and their cost to the healthcare
system using the case of the United Kingdom.

SMBG Accuracy

Glycemic Control

Short-Term Clinical Outcomes Long-Term Clinical Outcomes

Treatment Costs Healthcare System Costs Quality of Life
FIGURE 4.1
Short-term and long-term consequences of BGM system accuracy.