Cost of illness of type 2 diabetes mellitus with a cardiovascular comorbidity and comparison with guideline recommendations: a German claims data analysis.

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a widespread disease which is often followed and exacerbated by cardiovascular disease (CVD). Both the commonness of T2DM and the co-occurrence with CVD put a considerable burden on healthcare systems. Although corresponding treatment options and guidelines are well established, publications suggest subpar adherence to treatment guidelines in daily practice.

OBJECTIVES

We aim to quantify the healthcare resource utilization (HCRU) and cost of illness in persons with T2DM and CVD while distinguishing whether treatment followed guideline recommendations.

METHODS

The study was a retrospective analysis based on statutory health insurance claims data, comprising Germans with T2DM with an incident diagnosis of CVD during an overall study period between January 2015 and December 2019. HCRU was assessed as the number of outpatient and emergency department visits, as well as the number and duration of hospitalizations. Corresponding costs were also analyzed together with related pharmacy costs. Guideline adherence was assessed using the medication possession ratio and was categorized as completely, partly, or non-adherent.

RESULTS

Among 17,175 persons with T2DM and CVD observed in total, more than half (56.0%) were hospitalized at least once during the 12-month follow-up period and spent on average 20.3 days in the hospital. In addition, almost all patients (99.1%) had at least one outpatient visit, with more than 16 cases per patient-year (PY). For a great proportion of patients, treatment of CVD revealed to be not (9.4%) or only partly adherent (48.2%) to the corresponding guidelines. Excluding costs of the index case, total costs more than doubled from baseline (€7,488/PY) to €15,743/PY after the event. Costs were mainly driven by inpatient costs, followed by pharmacy and outpatient costs. While pharmacy costs were lower in patients, who were not or only partly treated according to guidelines, lower inpatient, outpatient, and overall costs were associated with adherence to guidelines.

CONCLUSIONS

Results from this claims data analysis confirm previous findings by reporting the HCRU and economic burden of T2DM associated with CVD, which are further exacerbated by subpar adherence to the respective guidelines. With T2DM and CVD being preventable diseases, adherence to guideline recommended treatment would have two-fold benefits by improving medical outcomes, as well as reducing overall costs and HCRU.