The composite metric Q-Score: A screening tool for assessment of short-term glycemic control

Background and aims Q-Score is a single-number metric summing up main factors of the glucose profile, which are central glycemic tendency, hyperglycemia, hypoglycemia, intra- and inter-daily variability. Here, we translate the Q-Score for analysis of ≥ 14-day CGM tracings and for assessment of short-term glycemic control using the target range 3.9 – 10 mmol/l. Methods: CGM-profiles were from non-interventional, retrospective cross-sectional studies. The Q-Score component ‚time above target range’ (TAR) was adjusted from 8.9 to 10 mmol/l using 3-day-sensor profiles (n=1,562). 285 people with diabetes using intermitted CGM (wear time ≥ 14 days) were enrolled to investigate correlation with fructosamin, glucose management indicator (GMI%), time in range (TIR%) and with the composite metric Glycemic Risk Index (GRI). Q-Score stability was addressed by correlation-based analysis.

Results There was a a high correlation applying both TARs (Q-ScoreTAR10= -0.03 + 1.00 Q-ScoreTAR8.9 ; r=0.997, p<0.001). Q-Score was stable after 13 days prior to TIR with 12 and variability (% CV) within 14 days. Q-Score components reached stability between 12 and 13 days. Hypoglycemia was the slowest with 15 days. Q-Score correlated to fructosamin, GMI and TIR (r=0.71, 0.884 and -0.874) as well as GRI (r=0.941). Q-Score indicated insufficient glycemic quality in 86% (218/251) of participants, mostly belonging to insulin-treated people. Glucose variability and hypoglycemia were responsible in type 1 and hyperglycemia in type 2 diabetes, respectively. Conclusions Q-Score is a potential screening tool for assessment of short-term glycemic control and can highlight glucose profile components requiring therapeutic action.

Publication History

Article published online:
02 May 2023