Real-world costs of obesity-related complications over eight years: a US retrospective cohort study in 28,500 individuals

BACKGROUND: Obesity-related complications (ORCs) are associated with high costs for healthcare systems. We assessed the relationship between comorbidity burden, represented by both number and type of 14 specific ORCs, and total healthcare costs over time in people with obesity in the USA. METHODS: Adults (≥ 18 years old) identified from linked electronic medical records and administrative claims databases, with a body mass index measurement of 30–< 70 kg/m(2) between 1 January 2007 and 31 March 2012 (earliest measurement: index date), and with continuous enrolment for ≥ 1 year pre index (baseline year) and ≥ 8 years post index, were included. Individuals were grouped by type and number of ORCs during the pre-index baseline year. The primary outcome was annual total adjusted direct per-person healthcare costs. RESULTS: Of 28,583 included individuals, 12,686 had no ORCs, 7242 had one ORC, 4180 had two ORCs and 4475 had three or more ORCs in the baseline year. Annual adjusted direct healthcare costs increased with the number of ORCs and over the 8-year follow-up. Outpatient costs were the greatest contributor to baseline annual direct costs, irrespective of the number of ORCs. For specific ORCs, costs generally increased gradually over the follow-up; the largest percentage increases from year 1 to year 8 were observed for chronic kidney disease (+ 78.8%) and type 2 diabetes (+ 47.8%). CONCLUSIONS: In a US real-world setting, the number of ORCs appears to be a cost driver in people with obesity, from the time of initial obesity classification and for at least the following 8 years.