REFER study

FreeStyle Libre system^₼ in T2D with basal-bolus insulin

Evaluating the FreeStyle Libre system^₼ in type 2 diabetes managed with basal-bolus therapy

REFER investigated the impact of the FreeStyle Libre system on HbA1c in type 2 diabetes (T2D) managed with basal-bolus insulin treatment.¹ Real-world data were collected in 3 parallel, retrospective, non-interventional chart review studies of type 2 diabetes patients using the FreeStyle Libre system at diabetes centres in Austria, France and Germany. In these real-world settings, using the FreeStyle Libre system for 3–6 months significantly reduced HbA1c levels in people with T2D managed with basal-bolus insulin therapy.

A1c = HbA1c

Study objective

Evaluate the efficacy of the FreeStyle Libre system on glycaemic control in patients with T2D managed by basal-bolus insulin therapy in real-world clinical settings.

Study design and study population

REFER comprised 3 parallel, retrospective, non-interventional, single-arm chart review studies conducted in Austria, France and Germany (6 centres per country).

Inclusion criteria

≥18 years
T2D
On basal-bolus insulin regimen for ≥1 year
Use of FreeStyle Libre system for ≥3 months at time of data collection
Baseline HbA1c of 64–108 mmol/mol (8.0 %-12.0%)
HbA1c measurement 3–6 months after initiation of device use

Key exclusion criteria

Pregnancy
Receiving dialysis treatment
Participation in a conflicting study

Primary outcome

➤ Change in HbA1c levels from baseline (measured ≤3 months^† before starting FreeStyle Libre system) to an HbA1c measurement taken 3–6 months after commencement of device use^††.

Subgroup analyses (all countries)

Baseline HbA1c
<75 mmol/mol (<9.0%) 
≥75 mmol/mol (≥9.0%)

Duration of insulin use
<9 years
≥9 years

Age 
<65 and ≥65 years

BMI 
<30 and ≥30

Sex

Study results

Key patient baseline characteristics¹

A total of 363 medical records were included in the meta-analysis (92 from Austria, 88 from France and 183 from Germany). Baseline demographic and clinical characteristics were similar across all countries (Table 1, Fig 1).

Primary outcome

HbA1c changes

➤ Overall, mean HbA1c decreased by 9.7 mmol/mol ± 0.6 (0.9% ± 0.05, p < 0.0001) from baseline to the final phase: from 73.3 mmol/mol ± 9.8 (8.9% ± 0.9) to 63.6 ± 10.6 mmol/mol (8.0% ± 1.0). HbA1c changes per country were as follows (Table 2, Fig 1).

Figure 1 – Change in HbA1c from baseline per country and overall

Subgroup analyses

In all three countries: 

➤ HbA1c decrease was more pronounced in patients with baseline HbA1c levels ≥75 mmol/mol (≥9.0%) (Fig 2).
➤ HbA1c improvements were seen across age, sex, duration of insulin use and BMI categories (Fig 2).
➣ No significant difference in HbA1c effects was seen between subgroups of these categories.

Figure 2 – Change in HbA1c from baseline per subgroup analysis

Summary

REFER was the first analysis of real-world data to demonstrate the beneficial impact of FreeStyle Libre system on A1c levels in type 2 diabetes patients treated with basal-bolus insulin.

After 3–6 months of use, the FreeStyle Libre system significantly reduced HbA1c levels in T2D patients on a basal-bolus insulin regimen.

₼Sales of the original FreeStyle Libre system have been discontinued in EU & UK markets. In these markets, the FreeStyle Libre 2 and 3 systems are for sale, providing the same benefits as the original FreeStyle Libre system, with the added functionalities of optional Real-Time Alarms.
†If >1 HbA1c test result was available, the result closest to the index date was extracted for use. 
‡Test performed ≥90 days but <194 days after initiating Freestyle Libre; if >1 HbA1c result was available, the result closest to 135 days after the index date was used.

References

1 Kröger J, Fasching P, Hanaire H. Three European retrospective real-world chart review studies to determine the effectiveness of flash glucose monitoring on A1c in adults with type 2 diabetes. Diabetes Ther. 2020;11(1):279-291. doi:10.1007/s13300-019-00741-9.

ADC-89712 v.2 03/26

REFER study

Evaluating the FreeStyle Libre system^₼ in type 2 diabetes managed with basal-bolus therapy

Study objective