Reduced Workload in the STAR Glycaemic Control Framework: Quantifying the Safety Trade-Off

Introduction:
The Stochastic Targeted (STAR) glycaemic control (GC) framework is a model-based, risk-based insulin and
nutrition protocol providing safe, effective GC to nearly all patients. STAR currently uses 1-3 hourly
measurement intervals, averaging 12 measurements per day. This study assesses the impact of increasing its
measurement interval up to 6-hourly on GC safety and efficacy.
Methods:
STAR identifies patient-specific model-based insulin sensitivity (SI) using clinical data and forecasts its future
variability to obtain an insulin and nutrition intervention minimising hypoglycaemic risk. STAR also modulates
nutrition intervention to reduce persistent hyperglycaemia for highly insulin resistant patients. STAR is adapted
to allow 1-6 hourly measurement interventions. Validated virtual trials assess GC outcomes of the original STAR
(STAR-3H) and the STAR 1-6 hourly (STAR-6H) protocols on the same 681 underlying virtual patients based on
retrospective clinical data.
Results:
Results are presented in Table 1. As expected, STAR-6H results in lower workload than STAR-3H (8 vs 12
measures per day). The resulting median [IQR] BG is higher in STAR-6H (124 [113 139] mg/dL) compared to
STAR-3H (117 [106 131] mg/dL), using significantly lower insulin (2.5 [1.5 3.0] vs 3.2 [2.0 5.0] U/h). Overall, there
is a slight decrease in the %BG in target band (80-145 mg/dL) for STAR-6H (80% vs 83%), and slightly higher %
BG above target (18% vs 15%). Importantly, the incidence of moderate hypoglycaemia is similar (1.6%), but
STAR-6H has higher incidence of severe hypoglycaemia (19 (2.8%) vs 14 (2.1%) patients). These results are
achieved with slightly lower nutrition for STAR-6H (90 [75 100] vs. 100 [85 100] %goal).
Conclusion:
The risks associated with the reward of reducing workload are slightly reduced safety, performance, and
nutrition rates. Overall, despite using these longer measurements intervals, STAR still managed to provide
highly safe, effective GC for nearly all patients.