Cost-effectiveness of surgically induced weight loss for the management of type 2 diabetes: modelled lifetime analysis

Abstract

Objective: To estimate the cost-effectiveness of surgically induced weight loss relative to conventional therapy for the management of recently diagnosed type 2 diabetes in class I/II obese patients.

Research Design and Methods: This study builds upon a within-trial cost-efficacy analysis. The analysis compares the costs and quality-adjusted life years (QALYs) lived between the two intervention groups over the lifetime. Intervention costs were extrapolated based on observed resource utilisation during the trial. The proportion of patients in each intervention group with remission of diabetes at 2 years was as observed in the trial. Healthcare costs for patients with type 2 diabetes and outcome variables required to derive estimates of QALYs were sourced from published literature. A healthcare system perspective was adopted. Costs and outcomes were discounted annually at 3%. Costs are presented in 2006 Australian Dollars (AUD) (currency exchange: 1AUD: USD0.74).

Results: The mean number of years in diabetes remission over a lifetime were 11.4 for surgical therapy patients and 2.1 for conventional therapy patients. Over the remainder of their lifetime, surgical and conventional therapy patients lived 15.7 and 14.5 discounted QALYs respectively. The mean discounted lifetime costs were AUD98,900 per surgical therapy patient and AUD101,400 per conventional therapy patient. Relative to conventional therapy, surgically induced weight loss was associated with mean healthcare savings of AUD2,400 and 1.2 additional QALYs per patient.

Conclusion: Surgically induced weight loss is a dominant intervention (both saves healthcare costs and generates health benefits) for managing recently diagnosed type 2 diabetes in obese patients in Australia.