Economic Evaluation of Quality Improvement Interventions Designed to Improve Glycemic Control in Diabetes: A Systematic Review and Weighted Regression Analysis

Abstract

OBJECTIVE Quality improvement (QI) interventions can improve glycemic control, but little is known about their value. We systematically reviewed economic evaluations of QI interventions for glycemic control among adults with type 1 or type 2 diabetes. RESEARCH DESIGN AND METHODS We used English-language studies from high-income countries that evaluated organizational changes and reported program and utilization-related costs, chosen from PubMed, EconLit, Centre for Reviews and Dissemination, New York Academy of Medicine's Grey Literature Report, and WorldCat (January 2004 to August 2016). We extracted data regarding intervention, study design, change in HbA1c, time horizon, perspective, incremental net cost (studies lasting ≤3 years), incremental cost-effectiveness ratio (ICER) (studies lasting ≥20 years), and study quality. Weighted least-squares regression analysis was used to estimate mean changes in HbA1c and incremental net cost. RESULTS Of 3,646 records, 46 unique studies were eligible. Across 19 randomized controlled trials (RCTs), HbA1c declined by 0.26% (95% CI 0.17–0.35) or 3 mmol/mol (2 to 4) relative to usual care. In 8 RCTs lasting ≤3 years, incremental net costs were $116 (95% CI −$612 to $843) per patient annually. Long-term ICERs were $100,000–$115,000/quality-adjusted life year (QALY) in 3 RCTs, $50,000–$99,999/QALY in 1 RCT, $0–$49,999/QALY in 4 RCTs, and dominant in 1 RCT. Results were more favorable in non-RCTs. Our limitations include the fact that the studies had diverse designs and involved moderate risk of bias. CONCLUSIONS Diverse multifaceted QI interventions that lower HbA1c appear to be a fair-to-good value relative to usual care, depending on society’s willingness to pay for improvements in health.