Dynamics of switching, adherence, and persistence of dipeptidyl peptidase-4 inhibitors use: A nationwide cohort study

Abstract

AimsTo characterise the patterns of switching, adherence, and persistence among adults aged ≥18 years with diabetes prescribed dipeptidyl peptidase-4 inhibitors (DPP-4is) in Australia. MethodsThe analysis included 15,915 adults newly prescribed DPP-4is (sitagliptin = 9576; vildagliptin = 1130; saxagliptin = 1126; linagliptin = 3560; and alogliptin = 523). Multivariable logistic regression model was used to compare the non-adherence (proportion of days covered [PDC] <0.80) rates whereas Cox proportional hazards regression models were used to compare switching and non-persistence (≥90-day gap) among different DPP4-is over 12-months. ResultsOverall, 36.0% (5722/15,915) of DPP-4i users were non-adherent and 30.0% (4775/15,915) were non-persistent at 12-months. Compared to sitagliptin, vildagliptin, linagliptin, and alogliptin were not associated with higher non-adherence and non-persistence. However, saxagliptin was associated with a higher likelihood of being non-adherent (odds ratio 1.41, 95% confidence interval [CI] 1.23–1.60) or non-persistent (hazard ratio 1.27, 95% CI 1.15–1.42) compared to sitagliptin. Just 3.2% of people switched between different DPP-4is. Compared to sitagliptin, people initiated on vildagliptin, saxagliptin, alogliptin, and linagliptin were more likely to switch. ConclusionsWe found no significant differences in the adherence and persistence rates between alogliptin, vildagliptin or linagliptin and sitagliptin. However, saxagliptin was associated with higher non-adherence and non-persistence compared to sitagliptin. Switching was lowest amongst users of sitagliptin.