Trends in the Dispensing and Costs of Glucose-Lowering Medications Among Older Australians: Findings from National Claims Data

Changes in the use of diabetes drugs among community-dwelling people with Alzheimer's disease

Background

Type 2 diabetes is common in persons with Alzheimer’s disease (AD). Management of diabetes in persons with AD is challenging due to changing goals of care and susceptibility to adverse drug events including hypoglycemia. The aim of this study was to investigate the prevalence of diabetes drug use from 5 years before to 5 years after the time of AD diagnosis among persons with and without AD.

Methods

This was a nationwide register-based study of persons with and without AD and diabetes in Finland. We analyzed data from the Medication Use and Alzheimer’s disease (MEDALZ) study that included 70,718 community-dwelling people diagnosed with AD from 2005 to 2011. The study population included 8418 persons with AD and 6666 matched persons without AD who were diagnosed with diabetes 5 years before AD diagnosis (index date). We defined the prevalence of diabetes drug use in three-month evaluation periods from 5 years before until 5 years after the index date.

Results

Nearly all people with diabetes (94% in both cohorts) used one or more diabetes drugs on the index date. The most prevalent drug metformin was used by 60.9% of people with AD and 59.1% of people without AD. The next most prevalent drugs were sulfonylureas and insulin. The prevalence of diabetes drug use was similar in people with and without AD but began to decline 1 year after AD diagnosis in the AD cohort compared to non-AD cohort.

Conclusions

The decline in diabetes drug use after AD diagnosis may be attributed to clinicians and patients seeking to avoid serious adverse drug events including hypoglycemia. In addition, the findings may reflect personalized glycemic control and unintentional weight loss in persons with AD reducing the need for diabetes drugs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02694-w.

Prescription trends and costs of diabetes medications in Australia between 2003 and 2019: an analysis and review of the literature

BACKGROUND

Since the turn of the century, the prevalence of diabetes mellitus in Australia has increased, primarily due to rising rates of Type 2 diabetes. Simultaneously, the landscape of diabetes medications has evolved significantly. The change in prescribing trends and public spending on diabetes medications within Australia during this period are not well defined.

AIMS

To establish the frequency and cost of dispensed diabetes medications in the Australian public healthcare system between 2003 and 2019.

METHODS

We performed a longitudinal nationwide observational study using data obtained from the Pharmaceutical Benefits Scheme (PBS) and Medicare Benefits Schedule websites, which contain information on frequency and spending of diabetes medications dispensed in Australia.

RESULTS

The total number of PBS-subsidised prescriptions dispensed for diabetes increased from 5 218 690 in 2003 to 12 188 568 in 2019, and spending increased from $117 241 031 to $598 904 983. Of the non-insulin agents, metformin was consistently the most frequently dispensed agent, with a rapid growth in metformin combination tablets. Dispensation of sulphonylureas and thiazolidinediones have declined, with a simultaneous increase in dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists.

CONCLUSIONS

Our data show a large growth in the use of diabetes medications between 2003 and 2019. The rapid growth in dispensing of drugs with proven cardiovascular and renal benefits reflect the evolving approach of diabetes treatment, from a historical approach targeting glycaemic control alone, to a modern individualised approach targeting specific co-morbidities.