Clinical and economic outcomes of multiple versus single long-acting inhalers in COPD.

OBJECTIVE: To compare healthcare resource utilization and healthcare costs between COPD patients who used multiple long-acting inhalers versus those who used a single long-acting inhaler.
METHODS: COPD patients meeting study inclusion criteria were identified in the Market Scan database (2004-2008) and were classified as being a multiple- or single-inhaler user. 11,747 multiple- and single-inhaler users were matched on baseline characteristics to balance disease severity. Patients were followed for 12 months. Incremental differences between the two groups were estimated for: number of exacerbations; time to first exacerbation; all-cause and COPD-related inpatient admissions, inpatient days, emergency room visits, urgent care visits, outpatient visits, and other medical services visits; all-cause and COPD-related healthcare costs. Multivariate regression analyses were also used to control for a number of potentially confounding factors.
RESULTS: After controlling for a number of potentially confounding factors, multiple-inhaler users experienced significantly more exacerbations (0.52; p < .0001) and had a higher risk of exacerbation (HR = 1.40; p < .0001) than single-inhaler users. Multiple-inhaler users also incurred significantly more inpatient admissions (IRR = 1.15; p < .0001), inpatient days (IRR = 1.20; p < .0001), urgent care visits (IRR = 1.10; p = 0.0026), outpatient visits (IRR = 1.06; p < .0001), and other medical services visits (IRR = 1.12; p = <.001) than single-inhaler users, resulting in significantly higher all-cause health care costs ($3,319; p < .0001). Results of COPD-related resource use and costs were comparable.
CONCLUSIONS: After controlling for a number of potentially confounding factors, multiple-inhaler users had more exacerbations, a higher risk of exacerbation, and higher healthcare resource utilization and costs compared to single-inhaler users.