Impact of socioeconomic position on initiation of SGLT-2 inhibitors or GLP-1 receptor agonists in patients with type 2 diabetes – a Danish nationwide observational study

Abstract

Summary Background Low socioeconomic position may affect initiation of sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and glucacon-like-peptide-1 receptor agonists (GLP-1RA) among patients with type 2 diabetes (T2D). We examined the association between socioeconomic position and initiation of SGLT-2i or GLP-1RA in patients with T2D at time of first intensification of antidiabetic treatment. Methods Through nationwide registers, we identified all Danish patients on metformin who initiated second-line add-on therapy between December 10, 2012, and December 31, 2020. For each time period (2012-2014, 2015-2017, and 2018-2020), we used multivariable multinomial logistic regression to associate disposable income, as proxy for socioeconomic position, with the probability of initiating a specific second-line treatment at time of first intensification. We reported probabilities standardised to the distribution of demographics and comorbidities of patients included in the last period (2018-2020). Findings We included 48915 patients (median age 62 years; 61·7% men). In each time period, high-income patients were more often men and had less comorbidities as compared with low income-patients. In each time period, the standardised probability of initiating a SGLT-2i or a GLP-1RA was significantly higher in the highest income group compared with the lowest: 11·4% vs. 9·5% (probability ratio [PR] 1·21, 95 % confidence interval [CI] 1·01-1·44) in 2012-2014; 22·6% vs. 19.6% (PR 1·15, CI 1·05-1·27) in 2015-2017; and 65·8% vs. 54·8% (PR 1·20, CI 1·16-1·24) in 2018-2020. The differences by income were consistent across multiple subgroups. Interpretation Despite a universal healthcare system, low socioeconomic position was consistently associated with a lower probability of initiating a SGLT-2i or a GLP-1RA. These disparities may widen the future socioeconomic gap in cardiovascular outcomes. Funding The work was funded by unrestricted grants from ‘Region Sjaelland Den Sundhedsvidenskabelige Forskningsfond’ and ‘Murermester Lauritz Peter Christensen og hustru Kirsten Sigrid Christensens Fond’.

Understanding the restrictions in the prescription and use of potentially beneficial diabetes medications associated with low socio-economic status

“…6 Health-related behavior has been identified as a mediator of this association. 6 It is, therefore, not surprising that in the present study, a diagnosis of coronary, cerebrovascular or peripheral vascular disease, heart failure or chronic kidney disease was higher in those with a low disposable income, 5 providing more convincing reasons for a use of medications addressing these risks in those with a lower socioeconomic status, but the opposite was observed.…”

“…The initiation of any pharmacological treatment should be the result of shared decision making between patients and health care professionals. 3 The results by Falkentoft et al 5 seem to indicate that the relation of perceived benefits versus costs or potential harms of initiating SGLT-2 Is or GLP-1 RAs is different between those with high vs. low disposable incomes.…”

“…Falkentoft et al 5 now provide evidence that the likelihood for a prescription of SGLT-2 Is or GLP-1 RAs as a second glucose-lowering medication added to pre-existing metformin treatment depends on disposable income (a surrogate parameter for the socioeconomic status). They find that in Denmark, the use of SGLT-2 Is or GLP-1 RAs has increased from periods 2012-2014 (these classes were approved, but evidence for CV benefits was lacking), 2015-2017 (scientific evidence for CV benefits were first published), and 2018-2020 (strong guideline recommendations were available), but that the probability ratio was approximately 20% higher for those in the highest (compared to the lowest) income quartile.…”

“…Falkentoft et al 5 stress that in the public Danish health care system, medication costs are mainly public expenses, with a co-payment of up to 574 € per patient. This amount appears to be low, but this may be perceived in a different way by patients, considering that this represents 1.2 % of the yearly income for those in the highest, but 2.8 % in the lowest income quartile.…”

“…It appears worth mentioning that Falkentoft et al 5 only examined the situation when a second glucose-lowering medication was to be added to first-line metformin. In cardiovascular outcomes trials comparing novel glucose-lowering medications with placebo treatment, a much wider range of diabetes stages was studied, with a substantial proportion of patients using combinations of oral agents or even insulin.…”