How frequently do you encounter patients on three or more insulin injections per day (multiple‑daily‑injection therapy) in a typical outpatient diabetes clinic?

Frequency of Patients on Multiple Daily Insulin Injections in Outpatient Diabetes Clinics

Patients requiring three or more insulin injections per day are extremely common in modern diabetes practice, representing the standard of care for virtually all type 1 diabetes patients and a substantial proportion of inadequately controlled type 2 diabetes patients.

Prevalence in Clinical Practice

Type 1 Diabetes Population

• Most people with type 1 diabetes should be treated with multiple daily injections (MDI) consisting of 3-4 injections per day of basal and prandial insulin or continuous subcutaneous insulin infusion (CSII) 1.
• This represents the foundational treatment approach for type 1 diabetes, meaning essentially 100% of type 1 diabetes patients should be on this regimen unless using an insulin pump 1.
• The American Diabetes Association explicitly states that MDI or CSII is recommended for "most people with type 1 diabetes," making this the default standard rather than an exception 1.

Type 2 Diabetes Population

• Insulin therapy becomes essential in type 2 diabetes patients when HbA1c is ≥10% (≥86 mmol/mol) after optimal use of other agents 2.
• Many type 2 diabetes patients progress to requiring intensive insulin therapy when conventional regimens (1-2 injections daily) fail to achieve glycemic targets 3.
• In correctional institution guidelines, multiple daily insulin injection therapy is recommended even in these challenging settings, indicating its widespread applicability 1.

Clinical Reality in Outpatient Settings

You should be seeing these patients very frequently in any diabetes-focused outpatient practice. The evidence demonstrates:

• Type 1 diabetes patients universally require this level of insulin intensity 1, 4.
• A significant subset of type 2 diabetes patients eventually require escalation to MDI when simpler regimens fail 2.
• The DCCT trial established this as standard practice decades ago (1993), and subsequent guidelines have only reinforced this approach 1.

Regarding CGM Benefit Claims

The premise that CGM benefits "only" those on three or more injections is outdated and incorrect based on current evidence:

• Early CGM use is now recommended for all adults with type 1 diabetes to improve glycemic outcomes, quality of life, and minimize hypoglycemia—not restricted by injection frequency 1.
• Automated insulin delivery systems should be offered to all adults with type 1 diabetes, further expanding CGM utility beyond simple injection counting 1.
• CGM may be useful as a supplemental tool even for patients on less intensive regimens 1.

HbA1c as Gold Standard

While HbA1c remains important for predicting long-term complications, this statement requires nuance:

• HbA1c is the primary target for glycemic control and correlates with long-term microvascular and macrovascular outcomes 1.
• However, for patients prone to glycemic variability, glycemic control is best evaluated by a combination of HbA1c with self-monitoring of blood glucose or CGM metrics 2.
• CGM-derived metrics (time in range, time below range, time above range) provide complementary information that HbA1c alone cannot capture, particularly regarding hypoglycemia risk 5.

Common Pitfalls to Avoid

• Do not assume MDI is rare or specialized therapy—it is the standard of care for type 1 diabetes 1, 4.
• Do not restrict CGM consideration only to those on MDI—current guidelines support broader use 1.
• Do not rely solely on HbA1c for glycemic assessment in patients with variability—incorporate CGM metrics when available 2.