Health Care Use and Costs in Individuals With Diabetes With and Without Comorbid Depression in Germany: Results of the Crosssectional DiaDec Study
Increased healthcare utilization and costs have been reported in individuals with diabetes with comorbid depression. Knowledge regarding cost differences between individuals with diabetes alone and those with diabetes and diagnosed/undiagnosed depression is however scarce. We therefore compared utilization and costs for patients with diabetes and no depression and patients with diabetes and documented depression diagnosis or self-reported depression symptoms for several cost components, including mental healthcare costs.
Research Design and Methods
Data from a 2013 cross-sectional survey of randomly sampled members of a nationwide German statutory health insurance (SHI) provider with diabetes (n=1,634) were linked individually with SHI data covering four quarters before and after the survey. Self-reported depression symptoms were assessed using the PHQ-9, with depression diagnosis taken from SHI data. We analyzed healthcare utilization and costs, using regression analysis to calculate cost ratios adjusted for sociodemographic/socioeconomic factors and comorbidities for two groups: A) no symptoms, no diagnosis; B) symptoms or diagnosis. Our explorative sub-analysis analyzed subgroups with either symptoms or diagnosis separately.
Annual mean total healthcare costs were higher for patients with comorbid depression (€5,629 (95% CI: €4,987-€6,407)) than without (€3,252 (95% CI: €2,976-€3,675), the cost ratio being 1.25 (1.14-1.36)). Regression analysis showed that excess costs were highly associated with comorbidities. Mental healthcare costs were very low for patients without depression (€2/€4) and still relatively low for those with depression (€111/€76).
Costs were significantly higher when comorbid depression was present, either as symptoms or diagnosed. Excess costs for mental-health services were rather low.