Abstract
Objective
To investigate the effect of an asthma care support program for patients under the age of 18 years.
Study design
A 1:1 matched cohort study design was used. The purpose of matching is to find a similar comparison group in terms of observable variables. The propensity score method of matching was used to find a suitable comparison cohort, which is similar at baseline to the treatment cohort. For each treatment cohort member, a comparison cohort member was selected on the basis of having the closest estimated propensity score. Once a comparison cohort was defined, variables were compared at baseline year to ensure the similarity of the two groups. The Kruskal-Wallis test was used for comparison of variables between the treatment and comparison cohorts due to the non-Gaussian distribution of variables. Finally, variables were compared during the program year to estimate the treatment effects of the disease management program.
Patient groups
318 asthma care support program participants and 318 matched non-participants.
Main outcome measures
The rates of medical service utilization including rates of hospitalization, emergency department (ED) visits, and selected clinical indicators including allergen immunotherapy, chest x-rays, influenza vaccinations, and pneumococcal vaccinations.
Results
Baseline matching resulted in no statistically significant difference between the treatment and matched cohorts. However, during the program period the treatment cohort had 35.6% fewer inpatient admissions (p = 0.045), 32.5% fewer ED visits (p = 0.007), 56.7% fewer asthma-related inpatient admissions (p = 0.008), 50.8% fewer asthma-related ED visits (p < 0.0001), 26.8% fewer chest x-rays (p = 0.036), and 51.6% more influenza immunizations (p = 0.046).
Conclusions
Where controlled randomized clinical trials cannot be performed, the use of propensity scores provides an alternative for the purpose of estimating a treatment effect using observational data. The current study employed a propensity score-matching methodology to select a subset of comparison units most comparable to treatment units. It documented the beneficial clinical outcomes of pediatric and adolescent participation in an asthma care support program which suggested a beneficial impact of monitoring, education, and more rigorous adherence to action plans for program participants.
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Acknowledgements
The authors were employed by McKesson Corporation in Broomfield, Colorado, USA, at the time of the study.
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Berg, G.D., Johnson, A. & Fleegler, E. Clinical and Utilization Outcomes for a Pediatric and Adolescent Telephonic Asthma Care Support Program. Dis-Manage-Health-Outcomes 11, 737–743 (2003). https://doi.org/10.2165/00115677-200311110-00005
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DOI: https://doi.org/10.2165/00115677-200311110-00005