H.L.HTUN.1, W.LIAN.1, R.H.F.LIM.1, D.E.K.CHEW.1, W-Y.LIM.1
Tan Tock Seng Hospital1
Little is known about the longitudinal trajectory of glycated haemoglobin (HbA1c) and its impact on potentially avoidable hospitalization (PAH). We evaluated the association between HbA1c trajectories and subsequent one-year risk of diabetes-related PAH in a group of diabetics managed in an outpatient setting.
We performed a retrospective cohort study of adult prevalent type 2 diabetes patients managed at specialist outpatient medical clinics in Tan Tock Seng Hospital from 2009-2017. Glycaemic control was assessed by longitudinal trajectory of HbA1c (≥3HbA1c measurements within a two-year period) using group-based trajectory modelling. We ascertained composites of PAH (short-/long-term diabetic complications/uncontrolled diabetes/lower-extremity amputation) from principal discharge diagnoses, using definitions by the Prevention Quality Indicators (Version2020). Poisson regression models were used to estimate risk ratio (RR) and 95% confidence interval (95%CI).
A total of 7710 patients were eligible. Four distinct HbA1c trajectories were found: low-stable (n=6205,80.5%), moderate-stable (n=1021,13.2%), high-persistent (n=203,2.6%), and high-decrease (n=281,3.6%). During one-year follow-up, 36.4%(n=2807) patients were admitted at least once. Of these, 5.2%(n=147/2807) were admitted for diabetes-related PAHs. Compared to low-stable group, high-persistent group had the highest risk of diabetes-related PAH (RR:3.90; 95%CI:2.15-7.08) followed by high-decrease group (RR:1.50, 95%CI: 0.68-3.30) and the moderate-stable group (RR:1.42, 95%CI:0.85-2.37), after adjusting for potential confounders.
Our results suggest that distinct HbA1c trajectories were associated with diabetes PAH in the subsequent year. Patients who achieved good glycaemic control following an extremely high HbA1c, had a lower risk compared to those with persistently high HbA1c.