Insulin Glargine U100 Utilization in Patients with Type 2 Diabetes in an Italian Real-World Setting: A Retrospective Study

Abstract

Background. This study is aimed at estimating the proportion of type 2 diabetes mellitus (T2DM) patients treated with basal insulin (insulin glargine U100) and at evaluating daily insulin dose, treatment pattern, and adherence to treatment of these patients. Methods. Data from administrative and laboratory databases of 3 Italian Local Health Units were retrospectively collected and analyzed. All patients with a diagnosis of T2DM between 01/01/2012 and 31/12/2012 were considered, and those with at least a prescription of insulin glargine between 01/01/2013 and 31/12/2014 were included and followed up for one year. For each patient, we evaluated HbA1c levels both at baseline and during the follow-up period and the daily average dose of insulin. Medication adherence was defined by using medication possession ratio (MPR) and reported as proportion of patients with MPR≥80%. Results. 7,422 T2DM patients were available for the study. According to the antidiabetic medication prescribed, patients were categorized into four groups: insulin glargine only, insulin glargine plus oral glucose-lowering drugs, insulin glargine plus rapid-acting insulin, and insulin glargine plus DPP-4 inhibitors. Median daily dose of insulin among insulin glargine only patients was higher than in other groups (35 IU vs. 20 IU, p<0.05), and a higher percentage of them achieved a target HbA1c value of less than 7.0% (53.8% vs. 30%, p<0.001). Adherence to insulin treatment was lowest (41%) in the insulin glargine only group compared to other groups (ranging from 58.4% to 64.4%), p<0.001. Conclusions. A large proportion of T2DM patients treated with insulin fail in achieving the glycemic target of HbA1c level<7%, irrespective of treatment regimen; however, basal insulin only is associated with lower therapeutic unsuccess. Adherence to antidiabetes medications is also suboptimal in these patients and should be addressed to improve long-term outcomes of reducing and preventing microvascular and macrovascular complications.

Adherence and Persistence to Basal Insulin Among People with Type 2 Diabetes in Europe: A Systematic Literature Review and Meta-analysis

“…Adherence/non-adherence to basal insulin was measured with several methods in the four included studies reporting results on insulin adherence. The most frequently used measure was MPR > 80%, which was used in two of the four studies [ 32 , 37 ]. MPR > 80% was the only measure that was used by more than one of the included studies.…”

“…MPR > 80% was the only measure that was used by more than one of the included studies. Among the included studies, half of them were based on registry data [ 32 , 37 ], whereas the other half were based on self-reported questionnaire data [ 15 , 30 ]. The size of study populations varied from 162 included people [ 15 ] to 2413 included people [ 32 ].…”

“…Among the included studies, half of them were based on registry data [ 32 , 37 ], whereas the other half were based on self-reported questionnaire data [ 15 , 30 ]. The size of study populations varied from 162 included people [ 15 ] to 2413 included people [ 32 ]. An overview of all included studies reporting results on insulin adherence/non-adherence is presented in Table 5 .…”

“…Figure 3 illustrates the proportion of people with T2D who were adherent to basal insulin treatment (defined as MPR > 80%) within the first 12 months of treatment, stratified by different types of basal insulin. The share of people with MPR > 80% ranged from 41% to 64% [ 32 , 37 ]. The pooled rate of people with MPR > 80% across the relevant studies was 55.6% (95% CI 45.3; 65.6).…”

“…Of the 12 studies included in this manuscript, four presented results on adherence/non-adherence [ 15 , 30 , 32 , 37 ] and nine presented results on persistence/non-persistence [ 9 , 16 , 25 , 31 , 33 – 37 ], one of which presented results on both adherence/non-adherence and persistence/non-persistence [ 37 ]. This last-mentioned study included people treated with all kinds of insulin, which is why it was not possible to extract results for basal insulin only.…”