Long-term health benefit and economic return of time in range (TIR) improvement in individuals with type 2 diabetes

Objective: Time in range (TIR) is an important metric to measure variability of blood glucose levels. The aim is to quantify the long-term health benefits and economic return associated with improved TIR for individuals with type 2 diabetes (T2D).

Method: A Markov model with three states (T2D, T2D with cardiovascular disease (CVD) and death) estimated 20-year medical costs, quality-adjusted life-years (QALY) gained and CVD risk under four TIR scenarios: >85%, 71%-85%, 51%-70% and ≤50%. The T2D population was identified using the National Health and Nutrition Examination Survey, and model parameters were sourced from literature. Costs were estimated from a healthcare sector perspective and standardized to 2021 US dollars. Cost ceilings were determined using three willingness-to-pay (WTP) thresholds: $100 000/QALY, $50 000/QALY and $0/QALY (cost-saving).

Results: Compared to TIR <50%, improving TIR to 51%-70% resulted in a 0.79 QALY increase and 4.91% CVD risk reduction; to 71%-85%, a 0.95 QALY increase and 6.24% CVD risk reduction; to >85%, a 1.18 QALY increase and 8.75% CVD risk reduction. To be cost-effective at $100 000/QALY, annual costs for TIR improvements from <50% to 51%-70%, 71%-85% and >85% should be <$1148, $4200 and $7252, respectively. To be cost-saving, these costs should be <$612, $2816 and $5021.

Conclusion: Improving TIR yields significant health benefits. We calculated feasible medical cost allocations for TIR improvements, informing the implementation of interventions like continuous glucose monitoring devices.