Asthma medication ratio predicts emergency department visits and hospitalizations in children with asthma

Medicare Medicaid Res Rev. 2013 Dec 16;3(4):mmrr.003.04.a05. doi: 10.5600/mmrr.003.04.a05. eCollection 2013.


Objective: To determine if the asthma medication ratio predicts subsequent emergency department (ED) visits and hospital admissions in children.

Design: Retrospective cohort with two year pairs.

Setting/participants: 2007-2009 South Carolina Medicaid recipients with persistent asthma age 2-18.

Main exposure: Controller-to-total asthma medication ratios were calculated for each patient in 2007 and 2008. Ratios range from 0-1 (1 = ideal, 0 = no controller).

Outcome measures: 2008 and 2009 asthma related ED visits, hospitalizations, and a combined outcome of ED visit or hospitalization in the subsequent 3, 6, and 12 month time periods.

Results: 19,512 patients were included. Mean age 8.9 years, 58% male, and 55% black. The ratio significantly predicted ED visits and hospitalizations over subsequent 3, 6, and 12 month time periods. The cut-point that maximized the ability to predict visits ranged from 0.4-0.6. A cutpoint of 0.5 was used in the final models. After controlling for age, race, gender, and rurality, patients with a ratio <0.5 were significantly more likely to have a subsequent emergent healthcare visit (OR 1.5-2.0). The ratio retained its predictive ability in both year-pairs for all three outcome variables, in all three time periods, with the exception of the 2008 ratio not predicting 2009 3-month and 6-month hospitalizations.

Conclusions: The asthma medication ratio is a significant predictor of ED visits and hospitalizations in children. Using a cutoff of <0.5 to signal at-risk patients may be an effective way for populations who would benefit from increased use of controller medications to reduce future emergent asthma visits. CPT only copyright XXXX-2012 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association. Applicable FARS/DFARS Apply to Government Use. Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use. The AMA does not directly or indirectly practice medicine or dispense medical services. The AMA assumes no liability for data contained or not contained herein. See attached CMS CPT 2013 end user license.

Keywords: Medicaid; chronic disease; pediatrics.

MeSH terms

  • Adolescent
  • Anti-Asthmatic Agents / therapeutic use*
  • Asthma / drug therapy*
  • Asthma / therapy
  • Child
  • Child, Preschool
  • Emergency Service, Hospital / statistics & numerical data*
  • Female
  • Hospitalization / statistics & numerical data*
  • Humans
  • Male
  • Medicaid / statistics & numerical data
  • Retrospective Studies
  • South Carolina / epidemiology
  • Treatment Outcome
  • United States


  • Anti-Asthmatic Agents