Persistence and Adherence to GLP-1 RA treatment in Type 2 Diabetes Mellitus: a Nationwide registry study

Abstract Background The use of glucagon-like peptide-1 receptor agonsists (GLP-1 RA) continues to rise and is increasingly important in the treatment of type-2 diabetes mellitus (T2DM). Though the use of GLP-1 RA continues to increase, persistence and adherence to therapy remains suboptimal. Purpose We aimed to assess the level of adherence and persistence to GLP-1 RA using real-world data and to investigate sociodemographic and clinical factors associated with discontinuation of GLP-1 RA therapy. Methods In this retrospective cohort study, all first-time users of GLP-1 RA with T2DM ≥18 years from 2007-2020 were identified using the Danish registries (Figure 1A-1B). All participants had 18 months of follow-up. Medication possession ratio (MPR) was calculated by summing days of medication supply from all dispensed prescription made during the study period divided by number of days in study period. MPR ≥0.80 was used to define adherence. Discontinuation was defined as >90 days between the last day of prescription coverage and the first day of a new dispensed prescription. Adherence to GLP-1 RA therapy and the risk of discontinuing therapy was estimated at 6- and 12-months of follow-up. Multivariable logistic regression was used to identify sociodemographic and clinical factors associated with discontinuing GLP-1 RA therapy. Results In total, 44,343 first-time users of GLP-1 RA with T2DM were identified (mean age: 58.6 years, 42.7% female, 21.3% had cardiovascular disease, median duration of T2DM was 6.8 years, median HbA1c was 65 mmol/mol). The absolute risk of discontinuing GLP-1 RA at 6 and 12 months was 14.2% (95%CI: 13.9-14.6) and 21.4% (95%CI: 21.1-21.8), respectively (Figure 2A). Of the 9,520 (21.5%) who discontinued therapy during the 12-month follow-up, 1,947 (20.5%) occurred within the first 31 days of treatment. At 6 months, 58.5% were adherent to GLP-1 RA therapy with a median MPR of 0.84 [IQR: 0.70-0.95]. At 12 months, 61.1% were adherent to therapy with a median MPR of 0.85 [IQR: 0.71, 0.94]. In the multivariable model, low (<40 years) and high age (>75 years), lower household income, educational level, longer diabetes duration, and higher comorbidity burden were associated with a higher risk of discontinuing GLP-1 RA whereas baseline HbA1c was not (Figure 2B-2E). Conclusion Approximately one in five patients discontinued therapy within 12 months and a little over 60% were adherent. Sociodemographic factors, including household income, age, and comorbidity burden were associated with risk of discontinuing GLP-1 RA therapy. Given the changing landscape of who should be treated with GLP-1 RA, the cardio-renal benefits reported in recent trials, and the ongoing trials in the field, future research into adherence and persistence to GLP-1 RA and possible interventions to improve these, are needed.