Clinical Inertia and 2-Year Glycaemic Trajectories in Patients with Non-Newly Diagnosed Type 2 Diabetes Mellitus in Primary Care: A Retrospective Cohort Study

OBJECTIVE: To analyse diabetes treatment, treatment change and self-management behaviours in association with 2-year glycaemic trajectories in patients with non-newly diagnosed type 2 diabetes mellitus in Chinese primary care. METHODS: This was an observational, multi-centre, longitudinal, retrospective cohort study. Clinical data of 4690 subjects were extracted from electronic medical records, including serial glycated haemoglobin A(1c) (HbA(1c)) measurements, antidiabetic medication records and compliance to exercise, diet, medications and self-monitoring of blood glucose (SMBG). Patterns of longitudinal HbA1c trajectories were identified using the percentage of HbA(1c) measurements <7.5% from the second available HbA(1c) measurement. Clinical relevance of the clusters was assessed through multivariable analysis. RESULTS: Approximately half of the participants demonstrated good glycaemic control; of these, 34.5% demonstrated stable, good control, and 13.7% demonstrated relatively good control. About 16.2% demonstrated moderate control, and 35.6% demonstrated poor control. From the good to poor control groups, the percentage of subjects treated with insulin at baseline and during the follow-up period increased gradually, while the percentage of subjects adhering to exercise, diet, medications and SMBG decreased gradually. Compared with baseline, the adherence to exercise, diet, medications and SMBG improved significantly. Approximately 50% and 26% of subjects in the two poorest control groups, respectively, experienced treatment changes. After multivariable adjustments, baseline HbA(1c) ≥7.5%, HbA(1c) change ≥−0.5% from baseline to visit 1, insulin treatment, treatment change, poor adherence to diet, exercise, SMBG during the follow-up period and HbA(1c) measurements <3 per year were significantly associated with poorer glycaemic control. CONCLUSION: We identified four longitudinal HbA(1c) trajectories in patients with non-newly diagnosed type 2 diabetes. Even if baseline HbA(1c) is suboptimal, aggressive treatment changes, good adherence during the follow-up period, ≥3 HbA(1c) measurements per year and reducing HbA(1c) levels to a certain extent by the first follow-up visit were important for good, stable, long-term glycaemic control.