Time delays between fingerstick glucose measurements and correctional insulin administration in the hospital: do they really matter?

Aims/hypothesis: Time delays exist between inpatient blood glucose measurements, insulin administration and meal timing. The clinical impacts of time delay on insulin dosing and hypoglycaemia risk have not been fully evaluated. Methods: In this single-centre observational study, hospitalised individuals treated with insulin wore blinded Dexcom G6 Pro continuous glucose monitors (CGM) and received usual diabetes care. CGM values were matched by time to point-of-care (POC) blood glucose values and correctional insulin administration episodes. For each matched episode, time delay between POC measurement and correctional insulin administration and the difference between corresponding CGM values were calculated. Clinical impact of time delay was identified if insulin dosing would have changed with an updated glucose measurement. Results: Across 243 participants, 2204 matched glucose-correctional insulin administration episodes were identified. Mean time delay (± SD) was 52.5 ± 37.4 min with mean absolute difference between CGM values of 1.0 ± 1.2 mmol/l. Had an updated CGM value at time of insulin administration been used, a different dose of correctional insulin may have been given in 28.4% of patient episodes. Conclusions/interpretation: Time delay between inpatient POC glucose measurements and correctional insulin administration varies widely and may alter insulin dosing. Future studies are needed to investigate the role of CGM in optimising insulin dosing in the hospital.