Anti-inflammatory Medication Adherence and Cost and Utilization of Asthma Care in a Commercially Insured Population

Published In: The Journal of Asthma, v. 47, no. 3, Apr. 2010, p. 323-329

Posted on on January 01, 2010

by Soeren Mattke, Paco Martorell, Seo Yeon Hong, Priya Sharma, Alison Evans Cuellar, Nicole Lurie

Read More

Access further information on this document at Informa Plc

This article was published outside of RAND. The full text of the article can be found at the link above.

OBJECTIVE: The authors hypothesized that adherence to anti-inflammatory treatment could reduce overall cost of asthma care, as higher spending on drugs would be offset by reductions in hospital and emergency care. METHODS: A retrospective observational study using 2 years of claims data for 41,234 commercially insured asthmatics on monotherapy with either leukotriene inhibitors (LI) or inhaled corticosteriods (ICS). Patients were grouped into adherence quartiles based on the percentage of days per year they had prescriptions filled (medication possession ratio). The relationship between adherence and four outcomes was examined: (1) emergency department (ED) visits, (2) hospitalizations, (3) nondrug net payments for asthma care, (4) total net payments for asthma care (including drug costs). Multivariate and logistic regression models adjusting for demographics, comorbidities, and measures of past asthma utilization were used. RESULTS: Adherence rates were low with a median medication possession ratio of 39% for LI and 15% for ICS. Both ED and hospital use was negatively associated with adherence to LI. Patients in the lowest quartile experienced 80 (95% confidence interval (CI) = 62-102) ED visits and 34 (95% CI = 22-52) admissions per 1000 patient-years compared to 36 (95% CI = 27-49) ED visits and 13 (95% CI = 8-22) admissions in the highest quartile. In contrast, ED visits and hospital admissions did not differ significantly between adherence groups for ICS. Total payments for asthma care increased significantly with higher adherence for both LI and ICS patients. Comparing the lowest and highest adherence quartile, payments per person per month increased significantly from $65.11 (95% CI = $57.02-$73.20) to $147.46 (95% CI = $139.48-$155.44) for patients on LI and from $38.71 (95% CI = $29.52-$47.90) to 93.13 (95% CI = $83.70-$102.56) for patients on ICS. The only subgroup, for which overall asthma payments did not increase with better adherence, were patients with past ED visit or hospital admission on LI. CONCLUSIONS: In this observational study, treatment with LI, but not with ICS, appears to improve disease control, as evidenced by the reduction in the incidence of ED visits and hospitalizations in patients on LI. Savings generated by this reduction in high-cost events don't offset the increased payments for drugs in more adherence patients, except for selected high-risk patients.

This report is part of the RAND Corporation External publication series. Many RAND studies are published in peer-reviewed scholarly journals, as chapters in commercial books, or as documents published by other organizations.

Our mission to help improve policy and decisionmaking through research and analysis is enabled through our core values of quality and objectivity and our unwavering commitment to the highest level of integrity and ethical behavior. To help ensure our research and analysis are rigorous, objective, and nonpartisan, we subject our research publications to a robust and exacting quality-assurance process; avoid both the appearance and reality of financial and other conflicts of interest through staff training, project screening, and a policy of mandatory disclosure; and pursue transparency in our research engagements through our commitment to the open publication of our research findings and recommendations, disclosure of the source of funding of published research, and policies to ensure intellectual independence. For more information, visit

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.