SAT-288 Trends in pharmacotherapy for diabetes in a large Australian cohort: results from the EXTEND45 study

Abstract

Aim: We sought to examine temporal trends in the prescribing patterns of glucose lowering agents in Australia in patients with diabetes. Background Rising diabetes rates are increasing the global burden of chronic kidney disease (CKD). Glycemic control remains a key strategy for retarding CKD progression. Multiple factors may influence prescribing practice of glucose lowering pharmacotherapies including health provider restrictions on therapy combinations, patient factors such as age, comorbidities and level of renal function, and contemporary recommendations in national and international guidelines. The EXTEND45 cohort study links health information on consenting participants of the 45 and Up Study (2006-2009) with administrative health information from the Medicare Benefits Schedule (MBS) and Pharmaceutical Benefits Scheme (provided by the Department of Human Services), community pathology providers and other routinely collected health information sources. Linkage was performed by the Centre for Health Record Linkage and the Sax Institute (PBS and MBS). We identified a population-based cohort (2006-2014) of people aged ≥45 years who met pre-specified criteria for diabetes: self-report of diabetes, a HbA1c result ≥6.5%, a fasting serum glucose result >7.0 mmol/L, a random serum glucose >11.1 mmol/L, dispensed oral glucose lowering (OGL) medication and/or insulin analogue. Persons were considered to have prevalent diabetes if they had any of the diagnostic criteria prior to their 45 and Up Study recruitment date, and incident diabetes if they met the criteria after this date. OGL treatment episodes were analysed from the date of recruitment into the study or the date of diabetes diagnosis, until death, relocation outside the state of NSW, or June 30 2014. Treatment episodes were defined as the period a patient adhered to a particular regimen of pharmacotherapy without any breaks in treatment of two or more standard coverage days (SCD). SCDs relate to the number of treatment days covered by a single script and vary by drug agent. Episodes were attributed to the calendar year in which they commenced and were categorised into six pre-defined patterns of glucose lowering medication use:1. Never treated with pharmacotherapy2. Monotherapy (one OGL agent)3. Dual therapy (two OGL agents)4. Triple or more therapy (three or more OGL agents)5. Insulin treatment (+/- one or more OGL agent)6. Treatment break We identified 24,236 participants with diabetes who experienced 149,532 treatment episodes over a mean follow-up period of 4.97 years. Treatment episodes included: never treated (4.4%), monotherapy (33.1%), dual therapy (17.0%), triple or more therapy (4.0%), insulin-based therapy (21.7%) and treatment break (20.3%). Metformin (a biguanide) accounted for the majority (68.5%) of monotherapy episodes, followed by sulfonlyureas (23.1%). The combination of metformin and a sulfonylurea was the most common dual therapy treatment episode (56.1%) but became less common over the study period, falling from 75.5% of episodes in 2006 to 41.1% in 2014. Most treatment episodes in our cohort were for monotherapy-based regimens. There was a temporal change in the specific OGL agents prescribed within a dual therapy regimen, likely related to the availability of newer OGL agents in Australia.