Healthcare costs and utilization in individuals with diabetes with and without comorbid depression in Germany: Results of the cross-sectional DiaDec-Study

Einleitung:

Increased healthcare utilization and costs have been reported for individuals with diabetes and comorbid depression. Knowledge on how costs differ between individuals with documented depression diagnosis and/or self-reported depression symptoms is scarce.

Methoden:

Data of a cross-sectional survey among a random sample of a statutory health insurance (SHI) with diabetes (n = 1,634) was linked individually with SHI data covering four quarters before and after the survey. Self-reported depression symptoms were assessed using the Patient Health Questionnaire (PHQ-9). Depression diagnosis was taken from SHI data. We analyzed healthcare utilization and costs, and calculated cost ratios adjusted for sociodemographic/-economic factors and comorbidities for four groups: 1) no symptoms, no diagnosis, 2) no symptoms but diagnosis, 3) symptoms but no diagnosis, 4) symptoms and diagnosis.

Ergebnisse:

We found that annual mean total healthcare costs were higher for group 2 – 4, but costs due to psychotherapy and antidepressants were rather low (group 1: 3,342 €/2 €/4 €, group 2: 4,590 €/2 €/25 €, group 3: 5,437 €/95 €/39 €, group 4: 6,775 €/178 €/139 €). Regression analysis showed excess costs being highly associated with comorbidities. Fully adjusted cost ratios for total healthcare costs compared to group 1 were 1.26 (95% CI: 1.09 – 1.46) for group 2, 1.15 (1.03 – 1.28) for group 3, and 1.43 (1.23 – 1.67) for group 4.

Diskussion:

Combining diagnosis and symptoms of depression by data linkage helps to identify individuals with higher healthcare costs and generates knowledge on the distribution of costs. Costs were higher when comorbid depression was present. However excess costs for mental-health services were rather low, but they were unexpectedly high in group 3.