Methods: Following the standard procedure of systematic reviews, we conducted a review of studies that assessed the cost effectiveness of diabetes interventions, published in English between 1985 and 2005. The interventions were classified as those used for preventing diabetes, screening for undiagnosed diabetes, glycemic control, preventing diabetes-related complications, diabetes education, and other comprehensive interventions. Health benefits of the intervention were measured by life-year-gained (LYG) or quality-adjusted life year (QALY). We adjusted the cost-effectiveness ratios (CER) into 2005 US dollars.
Results: A total of 76 studies in 11-country settings were included in the final data abstraction. The quality of cost-effectiveness studies varied. The cost-effectiveness ratios of interventions for preventing diabetes among high risk individuals, including intensive lifestyle and medication interventions, ranged from cost-saving to $82,000 per QALY comparing with no intervention. The CERs of screening for undiagnosed diabetes ranged from $22,000-120,000 per QALY, comparing with no screening. The CERs of interventions for glycemic control including intensive insulin therapy, pioglitzone, metformin, self-management education, and home-based diabetes management ranged from cost-saving to $24,000 per LYG or $31,000 per QALY. The CERs of medications used for lipid-control ranged from cost-saving to $14,000 per LYG, or $72,000/QALY comparing with usual care. Tight hypertension control with ACE inhibitors, or beta-blockers, or irbeartan was cost-saving. Specialist-nurse-led disease management cost $6,000/QALY comparing with usual care. A multi-disciplinary intensive diabetes education program aiming to empower patients is cost-saving comparing with usual care without the education program. Conventional therapy plus eye disease screening and treatment, and plus ACE inhibitor treatment, both separately or combined, are cost-saving comparing with conventional insulin therapy alone. If conventional therapy is replaced by intensive insulin therapy, the cost-effectiveness ratio ranges from $12,000 to $15,000/LYG.
Conclusion: The cost-effectiveness of a wide-range of interventions used for preventing and controlling diabetes has been evaluated. Many interventions could be considered being cost-effective if $50,000/per LYG or QALY were used as a threshold for adopting decisions. Future cost-effectiveness studies should follow the recommended study guidelines to reduce heterogeneity of the study.