Where to Initiate Basal Insulin Therapy: Inpatient or Outpatient Department? Real-World Observation in China

BACKGROUND: This study aims to compare the effectiveness of initiating insulin therapy in inpatient and outpatient settings during a 6-month follow-up period among patients with type 2 diabetes mellitus (T2DM) in real-world settings. MATERIALS AND METHODS: The study was based on the ORBIT study, a real-world observational study which recruited patients with inadequate glycemic control by oral antidiabetic drugs (OAD) and initiated basal insulin (BI). We compare difference in initiation and evolution of insulin therapy and glycemic control after six months were compared between patients initiating basal insulin in the inpatient department (inpatient initiators) and those starting in outpatient (outpatient initiators) among participants without rehospitalization during the six months follow-up. RESULTS: Among all 18,995 participants in the ORBIT study, 56.0% were inpatient initiators and 44.0% outpatient. We conducted in-depth analysis among 14,860 patients without rehospitalization, 8129 inpatient initiators and 6731 outpatient initiators. (1) Inpatient initiators had lower insulin therapy persistence during six months (64.2%) than outpatient ones (78.6%) (p<0.001), which was mainly explained by more therapy switches from basal-bolus regimen to other therapies among inpatient initiators (50.1%) than that among outpatient initiators (37.5%) (p<0.001). (2) Inpatient initiation had a higher proportion of people achieving glucose targets (HbA1c <7%) than outpatient initiation. However, the benefit of inpatient initiation versus outpatient initiation was mainly observed among patients persisting with the initial insulin therapies (46.3% vs 39.5% p<0.001), rather than those nonpersistent (37.3% vs 36.2%, p=0.723). (3) Among patients with HbA1c <9%, taking only one OAD and without complications at baseline, inpatient insulin initiation did not show a higher proportion of people achieving glucose target than outpatient initiation (adjusted odds ratio=0.96, 95% CI: 0.76–1.21). CONCLUSION: For patients with HbA1c ≥9%, who were taking more than one OAD and had complications at baseline, initiating insulin treatment during hospitalization has a higher proportion of people achieving glucose target than that in the outpatient department, but the premise is that the initial therapy is acceptable and can be maintained after discharge. Patient-centered approach with co-agreed decision-making to select a suitable insulin regimen should be strengthened.