Numerator
Number of visits to an emergency department with a first-listed diagnosis of asthma (ICD-9-CM code 493) among persons aged 65 years and over
Denominator
Number of persons aged 65 years and over
Interventions
Home-based multi-trigger, multicomponent interventions with an environmental focus for persons with asthma aim to reduce exposure to multiple indoor asthma triggers (allergens and irritants).