OBJECTIVES: Type-2 diabetes mellitus (T2DM) is often accompanied by cardiovascular (CV) comorbidities. With this common disease pattern, treatment options and guidelines are well established. Rather little is known about the real-world implementation of these guidelines in daily practice.

The observational study presented here aims to characterize the CV and anti-diabetic (AD) treatment of T2DM patients with an incident CV disease throughout Germany, and analyze adherence to respective clinical guidelines with respect to specific outcomes such as mortality and (re-)hospitalization rates.

METHODS: We used 2019 German claims data and selected (prevalent) T2DM patients with the following (incident) CV comorbidities: Ischemic stroke (IS), myocardial infarction (MI), heart failure (HF), coronary artery disease (CAD), and (combined) HF/CAD. Guideline adherence was defined as "completely adherent", "partly adherent" or "non-adherent/untreated". Propensity score matching was performed to adjust for confounding.

RESULTS: CV-guideline adherence is increasing over time, with the share of completely adherent patients ranging from 29.6% (CAD/HF) to 57.5% (MI). The share of non-adherent patients is rather low, ranging from 1.8% (MI) to 14.2% (HF). One-year overall mortality was 9.2% in the patient group completely adherent to CV guidelines and 17.4% in the non-adherent patient group (p<0.0001). Similarly, one-year overall mortality was 2.6% in the patient group completely adherent to AD guidelines and 5.2% in the non-adherent patient group (p=0.0051). However, the rates for all-cause hospitalization were significantly higher in the patient group completely adherent to CV guidelines vs. non-adherent patients (66.0% vs. 62.7%, p=0.0024), most likely due to more intensive monitoring by physicians.

CONCLUSIONS: Our findings reveal potentially preventable deaths, and potential for optimization, both from a patient’s perspective (i.e., fewer hospitalizations) and an economical perspective. Adherence to guidelines must be improved, which requires joint efforts: improving the dissemination and communication of guidelines on the one hand and having continuous medical education for practitioners on the other hand.