Economic Burden Associated with Receiving Inhaled Corticosteroids with Leukotriene Receptor Antagonists or Long-Acting Beta Agonists as Combination Therapy in Older Adults.

Abstract

There is a paucity of literature on the health care expenditures associated with different pharmacologic treatments in older adults with asthma that is not well controlled on inhaled corticosteroids (ICS). To compare asthma-related and all-cause health care expenditures associated with leukotriene receptor antagonists (LTRA) versus long-acting beta agonists (LABA) when added to ICS in older adults with asthma. A retrospective cohort was constructed using 2009-2010 Medicare fee-for-service medical and pharmacy claims from a 10% random sample of beneficiaries continuously enrolled in Parts A, B, and D in 2009. The sample comprised patients who were aged 65 years and older, diagnosed with asthma, and treated exclusively with ICS + LABA or ICS + LTRA. Outcomes assessed were asthma-related expenditures (medical, pharmacy, and total) and all-cause health care expenditures (medical, pharmacy, and total). Outcomes were measured from the date of the first prescription for the add-on treatment (LABA or LTRA in combination with ICS) after having at least a 4-month "wash-in" period in which patients were receiving no controller, ICS alone, or ICS plus the add-on treatment of the follow-up period. Patients were followed until death, switching to or adding the other add-on treatment, or the end of the study (December 31, 2010). Multivariable regression models with nonparametric bootstrapped standard errors were used to compare all-cause and asthma-related expenditures per patient per month (PPPM) between ICS + LABA and ICS + LTRA users. All models were adjusted for demographics, comorbidities, and county-level health care access variables. The primary analysis included 14,702 patients, of whom 12,940 were treated with ICS + LABA and 1,762 were treated with ICS + LTRA. The mean (SD) follow-up periods were 12.3 (± 5.7) months for the ICS + LABA group and 15.3 (± 5.1) months for the ICS + LTRA group. Adjusted asthma-related expenditures PPPM were $400 for the ICS + LTRA group compared with $286 for the ICS + LABA group (P < 0.001). However, adjusted total all-cause expenditure PPPM was significantly lower for patients treated with ICS + LTRA ($6,087 for ICS + LTRA compared with $6,975 for ICS + LABA, P = 0.029). Older adults with asthma often experience economic burden from asthma and other chronic illnesses. Compared with ICS + LTRA, ICS + LABA was associated with lower asthma-related expenditures but with higher all-cause expenditures in older adults. Support for this study was provided by the University of Pittsburgh School of Pharmacy and the Pittsburgh Claude D. Pepper Older Americans Independence Center (NIA P30 AGAG024827). C. Thorpe reports grants from the National Institute of Aging during the conduct of this study. The other authors have nothing to disclose.