To assess the real-world impact of glucose-lowering drugs (GLDs) as an adjunct to insulin in Chinese patients with type 1 diabetes (T1DM).

Does glucose-lowering drugs (GLDs) as an adjunct to insulin improve clinical outcomes in Chinese patients with type 1 diabetes (T1DM) when used long-term in real-world practice?

Inclusion Criteria:

1. The research group consists of T1DM patients who first used oral hypoglycemic drugs from January 2013 to June 2024 and had a glycated hemoglobin level of >= 7%; The control group consisted of T1DM patients who maintained only insulin treatment regimen and had glycated hemoglobin >= 7%;
2. Age >= 18 years old;
3. At least one recorded HbA1c value before the start of treatment;
4. Maintain medication regimen as needed from baseline to at least 3 months;
5. Record the first glycated hemoglobin value after treatment.

Exclusion Criteria:

1. The patient had already used hypoglycemic drugs as an adjunct to insulin therapy before admission;
2. DKA、 Serious infection, perioperative status, severe trauma, pregnancy, patient's past or current involvement in interventional clinical research；
3. The standard for determining stress hyperglycemia by the supervising physician;
4. Patients who have no medication records or have not followed the treatment plan formulated by the doctor.

The study population consists of Chinese adult patients with type 1 diabetes mellitus (T1DM) who met the predefined eligibility criteria, enrolled from January 2013 to June 2024. The population is divided into two cohorts: the study cohort (T1DM patients who first used oral GLDs as adjuvant therapy to insulin) and the control cohort (T1DM patients who maintained insulin monotherapy). All participants had an HbA1c level of ≥ 7% at baseline, were ≥ 18 years old, had at least one recorded HbA1c value before treatment initiation, and maintained the required medication regimen for at least 3 months. Patients with DKA, severe comorbidities, stress hyperglycemia, or incomplete medical records were excluded. This study population is representative of real-world T1DM patients with poor long-term blood glucose control who require adjuvant GLDs or maintain insulin monotherapy, ensuring the external validity of the study results.