Using Cost-Effectiveness Analysis to Sharpen Formulary Decision-Making: The Example of Tiotropium at the Veterans Affairs Health Care System

• Published in: Value in health 2008-09, Vol.11 (5), p.980-988
• Main Authors: Onukwugha, Ebere, PhD, Mullins, C. Daniel, PhD, DeLisle, Sylvain, MD, MBA
• Format: Article
• Language: English
• Subjects: Aged; Bronchodilator Agents - economics; Bronchodilator Agents - therapeutic use; Chronic obstructive pulmonary disease; Confidence Intervals; Cost effectiveness; Cost-Benefit Analysis - economics; Decision Making; Female; Formularies, Hospital; formulary decision-making; Health care; Hospitalization; Hospitalization - economics; Hospitalization - statistics & numerical data; Hospitals, Veterans - economics; Humans; Internal Medicine; Ipratropium - economics; Ipratropium - therapeutic use; Male; Maryland; Medical Records Systems, Computerized; Models, Economic; Prices; Pulmonary Disease, Chronic Obstructive - drug therapy; Pulmonary Disease, Chronic Obstructive - economics; Respiratory Function Tests - economics; Retrospective Studies; Scopolamine Derivatives - economics; Scopolamine Derivatives - therapeutic use; Sensitivity and Specificity; tiotropium; Tiotropium Bromide; United States; United States Department of Veterans Affairs; Veterans; veterans population
• ISSN: 1098-3015; 1524-4733
• DOI: 10.1111/j.1524-4733.2007.00314.x

Abstract Objective To identify a cost-saving subset of criteria for the use of tiotropium at a Veterans Affairs Medical Center based on a cost-effectiveness analysis with ipratropium as the comparator. Methods Retrospective analysis of electronic medical records for the calendar year 2004 was conducted. The sample was drawn from a population at the Baltimore Veterans Affairs Medical Center that had a confirmed diagnosis of chronic obstructive pulmonary disease (COPD) and had filled prescriptions for ipratropium. The tiotropium sample was based on a modeled cohort of COPD patients who had received tiotropium. The analysis was conducted from the perspective of the Veterans Affairs Health Care System. The outcome was the incremental cost-effectiveness of tiotropium versus ipratropium. Results The incremental cost-effectiveness ratio (ICER) was $2360 per avoided exacerbation. Tiotropium cost-effectiveness increased with COPD severity and was cost-saving in patients with very severe disease (ICER = $−1818) and in patients with a previous COPD-related hospitalization (ICER = $−4472). The ICER was most sensitive to the relative effectiveness and price of tiotropium. Results identified the levels of treatment effectiveness and price beyond which tiotropium would become cost-saving relative to ipratropium. Conclusions The results support the existing Veterans Affairs practice of offering tiotropium to patients with COPD-related hospitalizations. Periodic review of the effectiveness data to determine whether tiotropium would be cost-saving in patients with very severe COPD is suggested. Cost-effectiveness analyses that identify practical criteria-for-use should become an integral part of the formulary process.