OBJECTIVES: Poor adherence to diabetes medications is associated with adverse clinical outcomes. The aim of this study was to characterise the patterns of switching, adherence and persistence of Sodium-glucose co-transporter 2 inhibitors (SGLT2is) use in Australia.

METHODS: Using Australian nationwide Pharmaceutical Benefits Scheme (PBS) data, we identified 11,981 adults aged ≥18 years who initiated SGLT2is (5993 dapagliflozin; 5988 empagliflozin) between September 2015 and August 2017. Adherence was measured via the proportion of days covered (PDC), persistence was defined as continuous use of SGLT2i until a gap of ≥90 consecutive days without medication on hand, and switching was defined as the first change from dapagliflozin to empagliflozin or vice versa. Generalised linear models were used to compare the adherence (PDC=continuous), logistic regression models were used to compare the likelihoods of being adherent (PDC≥0.80) and Cox proportional hazards regression models were used to compare the likelihoods of switching or being persistent between people prescribed empagliflozin and dapagliflozin over 12 months.

RESULTS: Overall, 65.8% of people dispensed SGLT2i were adherent (PDC≥0.80) and 72.1% were persistent at 12-months. The mean PDC over the 1-year was 0.79±0.27. In comparison to dapagliflozin, the use of empagliflozin was associated with higher adherence (PDC=continuous) (odds ratio [OR], 1.04, 95% confidence interval [CI] 1.03-1.05), being adherent (OR 1.39, 95% CI 1.29-1.51) and persisting for 12-months (hazard ratio [HR] 1.14, 95% CI 1.06-1.22). Just 4.3% of people switched between the SGLT2i. Compared to dapagliflozin, empagliflozin was associated with a lower likelihood of switching (HR 0.46, 95% CI 0.38-0.55).

CONCLUSIONS: Real world Australian nationwide data suggest that a considerable proportion of people prescribed SGLT2is are non-adherent or non-persistent. However, empagliflozin was found to be associated with better adherence and persistence as well as a lower likelihood of switching compared to dapagliflozin. Interventions to improve adherence among people prescribed SGLT2is are needed.