ordered; the total number of refills allowed in all of the statin orders; whether spacer was used; and whether nebulizer was used.
Insurance-related features	The primary payer’s insurance category (Medicaid, Medicare, Intermountain Healthcare’s own health insurance plan SelectHealth, other private insurance, or self- paid or charity) at the patient’s last visit; the number of insurances of the patient at the last visit; and the number of distinct primary payers across all of the patient’s visits.
Visit type-related features for the patient	The number of outpatient visits; the number of outpatient visits with a primary diagnosis of asthma; the number of outpatient visits to the patient’s PCP; the number of outpatient visits to specialists; the number of outpatient visits to allergists and immunologists; the number of ED visits; the length of stay of the last ED visit; the average length of stay of an ED visit; the number of inpatient stays; the total length of all of the inpatient stays; the average length of an inpatient stay; the number of admissions to intensive care; the length of the last intensive care unit stay; the average length of an intensive care unit stay; the last visit’s admission type (emergency, urgent, elective, or trauma); the most emergent one among all of the visits’ admission types; and the number of major visits for asthma.
Features related to appointment scheduling and visit status	The number of no shows; the number of cancelled appointments; the number of visits that were referred; the day of the week at the last ED visit’s admission time; the admit hour of the last ED visit; the discharge disposition location (home, left against medical advice, or other non-home location) of the last visit; the time between making the request and the actual visit of the last visit reflecting the request’s urgency; the shortest time between making the request and the actual visit among all of the visits; the number of days since the last inpatient stay; whether the last inpatient stay was through the ED; the number of days since the last outpatient visit; the number of days since the last ED visit; the number of times the patient left against medical advice; and the acuity level (resuscitation, emergent, urgent, semi-urgent, or non-urgent) of the last ED visit.
Features reflecting care continuity of the patient	The number of distinct EDs the patient visited; the number of distinct providers seen in outpatient visits; the number of distinct PCPs of the patient; the number of distinct medication prescribers; the number of distinct asthma medication prescribers; whether the patient was homeless; whether the patient had no phone number; and the number of distinct addresses the patient had, reflecting the number of times the patient moved.
Procedure-related features	The number of ICD-9 and ICD-10 procedure codes; the number of CPT/HCPCS procedure codes; the number of CPT/HCPCS procedure codes for influenza vaccination; the number of HCPCS procedure codes for home oxygen therapy; the number of CPT procedure codes for pulmonary function tests; the number of CPT procedure codes for the fractional exhaled nitric oxide (FeNO) test; and mechanical ventilation shown by ICD-9 and ICD-10 procedure codes.