Healthcare Costs Associated with Macrovascular, Microvascular, and Metabolic Complications of Type 2 Diabetes Across Time: Estimates from a Population-Based Cohort of over 0.8 Million Individuals with Up to 15 Years of Follow-Up

Objective: Developing country-specific unit-cost catalogs is a key area for advancing economic research to improve medical and policy decisions. However, little is known about how healthcare costs vary by type 2 diabetes (T2D) complications across time in Asian countries. We sought to quantify the economic burden of various T2D complications in Taiwan. Research Design and Methods: A nationwide population-based, longitudinal study was conducted to analyze 802,429 adults with newly-diagnosed T2D identified during 1999-2010 and followed-up until death or December 31, 2013. Annual healthcare costs associated with T2D complications were estimated with the multivariable generalized estimating equations models adjusting for individual characteristics. Results: The mean annual healthcare cost was $281 and $298 (2017 U.S. dollars) for a male and female, respectively, diagnosed with T2D at age <50 years, with diabetes duration of <5 years, and without comorbidities, antidiabetic treatments, and complications. Depression was the costliest comorbidity, increasing costs by 64-82%. Antidiabetic treatments increased costs by 72-126%. For non-fatal complications, costs increased from 36% (retinopathy) to 202% (stroke) in the event year, and from 13% (retinopathy or neuropathy) to 49% (heart failure) in subsequent years. Costs for the five leading costly non-fatal subtype complications increased by 201-599% (end-stage renal disease with dialysis), 37-376% (hemorrhagic/ischemic stroke), and 13-279% (upper/lower extremity amputation). For fatal complications, costs increased by 1,784-2,001% and 1,285-1,584% for cardiovascular and other-cause deaths, respectively. Conclusions: The cost estimates from this study are crucial for parameterizing diabetes economic simulation models to quantify the economic impact of clinical outcomes and determine cost-effective interventions.