Table 1.

Variables used for matching intervention patients with controls

Variable (no. of levels)	Categories	Comments
Age (7)a	1, 2, 3, 4, 5, 6–12, 13–18	Age at time of intervention/matched date
Race/ethnicity (6)	Asian/Pacific Islander, Black, Latino, White, Native American, Other
Gender (2)	Male, Female
Insurance status (3)	Public, Private, Changed status during evaluation period	Refers to a patient’s status at the time of the intervention or a control’s status at the corresponding matched hospitalization date (reference date)
Hospital utilization history	Range: 0–73	Calculated as “total summed hospital days” at CHRCO with a first-degree or second-degree diagnosis of asthma in the 24 months prior to the intervention date or corresponding matched hospitalization date (reference date)
ED utilization history	Range: 0–38	History of asthma-related ED visits w/o hospitalization: This variable was calculated as the total number of visits to the ED that did not result in an overnight hospitalization in the 24 months prior to intervention date or corresponding matched hospitalization date
Residence	Local or non-local	Local was defined as having a primary residence in the cities of Oakland or Berkeley
Year of hospitalization	2005, 2006, 2007	Year during which the intervention hospitalization (or reference hospitalization for controls) occurred

^aEach integer should be interpreted as X < (X + 1). Thus, age 1 represents any age between the first birthday and the day before the second birthday